From b0853510a59934153203e11c835598c5797760b9 Mon Sep 17 00:00:00 2001 From: "Henry H. Andrews" Date: Thu, 30 May 2024 13:18:13 -0700 Subject: [PATCH 01/37] Verbose Header Object documentation (3.1.1 port of 3867 1/2, 3904) This copies the relevant Parameter Object fields to the Header Object instead of relying on implicit guidance. The text for the fields has been edited to reflect that only headers are being described. This also include an example of describing a header using the `content` field, and explaining why it is necessary to do so. --- versions/3.1.1.md | 77 +++++++++++++++++++++++++++++++++++++++++++---- 1 file changed, 71 insertions(+), 6 deletions(-) diff --git a/versions/3.1.1.md b/versions/3.1.1.md index 0e282e2c83..df59b8a492 100644 --- a/versions/3.1.1.md +++ b/versions/3.1.1.md @@ -2453,18 +2453,56 @@ Expressions can be embedded into string values by surrounding the expression wit #### Header Object -The Header Object follows the structure of the [Parameter Object](#parameterObject) with the following changes: +The Header Object is used to describe headers for [HTTP responses](#responseHeaders) and for [individual parts in `multipart` representations](#encodingHeaders); see the relevant [Header Object](#headerObject) and [Encoding Object](#encodingObject) documentation for restrictions on which headers can be described. + +The Header Object follows the structure of the [Parameter Object](#parameterObject), including determining its serialization strategy based on whether `schema` or `content` is present, with the following changes: 1. `name` MUST NOT be specified, it is given in the corresponding `headers` map. 1. `in` MUST NOT be specified, it is implicitly in `header`. -1. All traits that are affected by the location MUST be applicable to a location of `header` (for example, [`style`](#parameterStyle)). +1. All traits that are affected by the location MUST be applicable to a location of `header` (for example, [`style`](#parameterStyle)). This means that `allowEmptyValue` and `allowReserved` MUST NOT be used, and `style`, if used, MUST be limited to `simple`. + +##### Common Fixed Fields + +These fields MAY be used with either `content` or `schema`. + +Field Name | Type | Description +---|:---:|--- +description | `string` | A brief description of the header. This could contain examples of use. [CommonMark syntax](https://spec.commonmark.org/) MAY be used for rich text representation. +required | `boolean` | Determines whether this header is mandatory. The default value is `false`. + deprecated | `boolean` | Specifies that a parameter is deprecated and SHOULD be transitioned out of usage. Default value is `false`. + +##### Fixed Fields for use with `schema` + +For simpler scenarios, a [`schema`](#headerSchema) and [`style`](#headerStyle) can describe the structure and syntax of the header. +When `example` or `examples` are provided in conjunction with the `schema` object, the example MUST follow the prescribed serialization strategy for the header. + +Serializing with `schema` is NOT RECOMMENDED for headers with parameters (name=value pairs following a `;`) in their values, or where values might have non-URL-safe characters; see [Appendix D](#serializingHeadersAndCookies) for details. + +Field Name | Type | Description +---|:---:|--- +style | `string` | Describes how the header value will be serialized. The default (and only legal value for headers) is `simple`. +explode | `boolean` | When this is true, header values of type `array` or `object` generate separate header values for each value of the array or key-value pair of the map. For other types of parameters this property has no effect. The default value is `false`. +schema | [Schema Object](#schemaObject) \| [Reference Object](#referenceObject) | The schema defining the type used for the header. +example | Any | Example of the header's potential value. The example SHOULD match the specified schema and encoding properties if present. The `example` field is mutually exclusive of the `examples` field. Furthermore, if referencing a `schema` that contains an example, the `example` value SHALL _override_ the example provided by the schema. To represent examples of media types that cannot naturally be represented in JSON or YAML, a string value can contain the example with escaping where necessary. +examples | Map[ `string`, [Example Object](#exampleObject) \| [Reference Object](#referenceObject)] | Examples of the header's potential value. Each example SHOULD contain a value in the correct format as specified in the header encoding. The `examples` field is mutually exclusive of the `example` field. Furthermore, if referencing a `schema` that contains an example, the `examples` value SHALL _override_ the example provided by the schema. + +See also [Appendix C: Using RFC6570 Implementations](#usingRFC6570Implementations) for additional guidance. + +##### Fixed Fields for use with `content` + +For more complex scenarios, the [`content`](#headerContent) property can define the media type and schema of the header, as well as give examples of its use. +Using `content` with a `text/plain` media type is RECOMMENDED for headers where the `schema` strategy is not appropriate. + +Field Name | Type | Description +---|:---:|--- +content | Map[`string`, [Media Type Object](#mediaTypeObject)] | A map containing the representations for the header. The key is the media type and the value describes it. The map MUST only contain one entry. ##### Header Object Example A simple header of type `integer`: ```json -{ +"X-Rate-Limit-Limit": { "description": "The number of allowed requests in the current period", "schema": { "type": "integer" @@ -2473,9 +2511,36 @@ A simple header of type `integer`: ``` ```yaml -description: The number of allowed requests in the current period -schema: - type: integer +X-Rate-Limit-Limit: + description: The number of allowed requests in the current period + schema: + type: integer +``` + +Requiring that a strong `ETag` header (with a value starting with `"` rather than `W/`) is present. Note the use of `content`, because using `schema` and `style` would require the `"` to be percent-encoded as `%22`: + +```json +"ETag": { + "required": true, + "content": { + "text/plain": { + "schema": { + "type": "string", + "pattern": "^\"" + } + } + } +} +``` + +```yaml +ETag: + required: true + content: + text/plain: + schema: + type: string + pattern: ^" ``` #### Tag Object From 1d5934053d05b63d083443dd9d1cc0e738f6a1cf Mon Sep 17 00:00:00 2001 From: Henry Andrews Date: Tue, 4 Jun 2024 08:58:18 -0700 Subject: [PATCH 02/37] Better wording (3.1.1 port of 3867 2/2) Co-authored-by: Ralf Handl --- versions/3.1.1.md | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/versions/3.1.1.md b/versions/3.1.1.md index df59b8a492..248b41aedd 100644 --- a/versions/3.1.1.md +++ b/versions/3.1.1.md @@ -2453,7 +2453,7 @@ Expressions can be embedded into string values by surrounding the expression wit #### Header Object -The Header Object is used to describe headers for [HTTP responses](#responseHeaders) and for [individual parts in `multipart` representations](#encodingHeaders); see the relevant [Header Object](#headerObject) and [Encoding Object](#encodingObject) documentation for restrictions on which headers can be described. +Describes a single header for [HTTP responses](#responseHeaders) and for [individual parts in `multipart` representations](#encodingHeaders); see the relevant [Response Object](#responseObject) and [Encoding Object](#encodingObject) documentation for restrictions on which headers can be described. The Header Object follows the structure of the [Parameter Object](#parameterObject), including determining its serialization strategy based on whether `schema` or `content` is present, with the following changes: @@ -2469,7 +2469,7 @@ Field Name | Type | Description ---|:---:|--- description | `string` | A brief description of the header. This could contain examples of use. [CommonMark syntax](https://spec.commonmark.org/) MAY be used for rich text representation. required | `boolean` | Determines whether this header is mandatory. The default value is `false`. - deprecated | `boolean` | Specifies that a parameter is deprecated and SHOULD be transitioned out of usage. Default value is `false`. + deprecated | `boolean` | Specifies that the header is deprecated and SHOULD be transitioned out of usage. Default value is `false`. ##### Fixed Fields for use with `schema` @@ -2481,7 +2481,7 @@ Serializing with `schema` is NOT RECOMMENDED for headers with parameters (name=v Field Name | Type | Description ---|:---:|--- style | `string` | Describes how the header value will be serialized. The default (and only legal value for headers) is `simple`. -explode | `boolean` | When this is true, header values of type `array` or `object` generate separate header values for each value of the array or key-value pair of the map. For other types of parameters this property has no effect. The default value is `false`. +explode | `boolean` | When this is true, header values of type `array` or `object` generate a single header whose value is a comma-separated list of the array items or key-value pairs of the map, see [Style Examples](#style-examples). For other data types this property has no effect. The default value is `false`. schema | [Schema Object](#schemaObject) \| [Reference Object](#referenceObject) | The schema defining the type used for the header. example | Any | Example of the header's potential value. The example SHOULD match the specified schema and encoding properties if present. The `example` field is mutually exclusive of the `examples` field. Furthermore, if referencing a `schema` that contains an example, the `example` value SHALL _override_ the example provided by the schema. To represent examples of media types that cannot naturally be represented in JSON or YAML, a string value can contain the example with escaping where necessary. examples | Map[ `string`, [Example Object](#exampleObject) \| [Reference Object](#referenceObject)] | Examples of the header's potential value. Each example SHOULD contain a value in the correct format as specified in the header encoding. The `examples` field is mutually exclusive of the `example` field. Furthermore, if referencing a `schema` that contains an example, the `examples` value SHALL _override_ the example provided by the schema. From d9b2707f3b2b3098fa8f8a53994756ed35785925 Mon Sep 17 00:00:00 2001 From: "Henry H. Andrews" Date: Tue, 28 May 2024 13:44:37 -0700 Subject: [PATCH 03/37] Improve media type encoding examples (3.1.1 port of 3864) * Replace the outdated "model" terminology with "schema" * Remove the outdated `text/plain` array example, which does not correlate with current OAS requirements * Rather than replacing the `text/plain` example direclty, enhance the example of serializing `application/json` content in `application/x-www-form-urlencoeded` request bodies. --- versions/3.1.1.md | 62 ++++++++++++++++++++++------------------------- 1 file changed, 29 insertions(+), 33 deletions(-) diff --git a/versions/3.1.1.md b/versions/3.1.1.md index 248b41aedd..e4330b6a81 100644 --- a/versions/3.1.1.md +++ b/versions/3.1.1.md @@ -1411,7 +1411,7 @@ This object MAY be extended with [Specification Extensions](#specificationExtens ##### Request Body Examples -A request body with a referenced model definition. +A request body with a referenced schema definition. ```json { "description": "user to add to the system", @@ -1487,36 +1487,6 @@ content: externalValue: https://foo.bar/examples/user-example.whatever ``` -A body parameter that is an array of string values: -```json -{ - "description": "user to add to the system", - "required": true, - "content": { - "text/plain": { - "schema": { - "type": "array", - "items": { - "type": "string" - } - } - } - } -} -``` - -```yaml -description: user to add to the system -required: true -content: - text/plain: - schema: - type: array - items: - type: string -``` - - #### Media Type Object Each Media Type Object provides schema and examples for the media type identified by its key. @@ -1676,9 +1646,35 @@ requestBody: properties: {} ``` -In this example, the contents in the `requestBody` MUST be stringified per [RFC1866](https://tools.ietf.org/html/rfc1866/) when passed to the server. In addition, the `address` field complex object will be stringified. +In this example, the contents in the `requestBody` MUST be encoded per [RFC1866](https://tools.ietf.org/html/rfc1866) when passed to the server. In addition, the `address` field complex object will be serialized to a string representation prior to encoding. + +When passing complex objects in the `application/x-www-form-urlencoded` content type, the default serialization strategy of such properties is described in the [Encoding Object](#encodingObject)'s [`style`](#encodingStyle) property as `form`. -When passing complex objects in the `application/x-www-form-urlencoded` content type, the default serialization strategy of such properties is described in the [`Encoding Object`](#encodingObject)'s [`style`](#encodingStyle) property as `form`. +With this example, given an `id` of `f81d4fae-7dec-11d0-a765-00a0c91e6bf6` and a US-style address (with ZIP+4) as follows: + +```json +{ + "streetAddress": "123 Example Dr.", + "city": "Somewhere", + "state": "CA", + "zip": "99999+1234" +} +``` + +Assuming the most compact representation of the JSON value (with unnecessary whitespace removed), we would expect to see the following request body, where space characters have been replaced with `+` and `+`, `"`, `{`, and `}` have been percent-encoded to `%2B`, `%22`, `%7B`, and `%7D`, respectively: + +```urlencoded +id=f81d4fae-7dec-11d0-a765-00a0c91e6bf6&address=%7B%22streetAddress%22:%22123+Example+Dr.%22,%22city%22:%22Somewhere%22,%22state%22:%22CA%22,%22zip%22:%2299999%2B1234%22%7D +``` + +Note that the `id` keyword is treated as `text/plain` per the [Encoding Object](#encodingObject)'s default behavior, and is serialized as-is. +If it were treated as `application/json`, then the serialized value would be a JSON string including quotation marks, which would be percent-encoded as `%22`. + +Here is the `id` parameter (without `address`) serialized as `application/json` instead of `text/plain`, and then encoded per RFC1866: + +```urlencoded +id=%22f81d4fae-7dec-11d0-a765-00a0c91e6bf6%22 +``` ##### Special Considerations for `multipart` Content From f19eceaff93f64ca8b96e6f9a2551bbecda2666e Mon Sep 17 00:00:00 2001 From: "Henry H. Andrews" Date: Mon, 6 May 2024 18:53:10 -0700 Subject: [PATCH 04/37] Clarications on RFC6570-derived behavior (3.1.1 port of 3818) This aligns allowReserved with style by similarly correlating it with RFC6570 operators. This will make it easier to write a more in-depth explanation of the process in an appendix. This also adds one of several appendixes to be added to clarify the most obscure details of Parameter Object and Encoding Object serialization. This clarifies the correspondence between OAS fields and RFC6570 operators, and acknowledges that some field values and combinations do not have analogues. It provides further guidance for how to use RFC6570 implementations to support these configurations. This includes a SHOULD directive regarding using RFC6570 expansion with the non-RFC6570 styles, as the use of "explode" and "allowReserved" does not otherwise make any sense. It perhaps could be a MUST. Examples are included to show both typical usage, and how to work around the lack of exact RFC6570 equivalences for certain configurations. --- versions/3.1.1.md | 245 +++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 243 insertions(+), 2 deletions(-) diff --git a/versions/3.1.1.md b/versions/3.1.1.md index e4330b6a81..3b4c204107 100644 --- a/versions/3.1.1.md +++ b/versions/3.1.1.md @@ -1182,11 +1182,13 @@ Field Name | Type | Description ---|:---:|--- style | `string` | Describes how the parameter value will be serialized depending on the type of the parameter value. Default values (based on value of `in`): for `query` - `form`; for `path` - `simple`; for `header` - `simple`; for `cookie` - `form`. explode | `boolean` | When this is true, parameter values of type `array` or `object` generate separate parameters for each value of the array or key-value pair of the map. For other types of parameters this property has no effect. When [`style`](#parameterStyle) is `form`, the default value is `true`. For all other styles, the default value is `false`. -allowReserved | `boolean` | Determines whether the parameter value SHOULD allow reserved characters, as defined by [RFC3986](https://tools.ietf.org/html/rfc3986#section-2.2) `:/?#[]@!$&'()*+,;=` to be included without percent-encoding. This property only applies to parameters with an `in` value of `query`. The default value is `false`. +allowReserved | `boolean` | When this is true, parameter values are serialized using reserved expansion, as defined by [RFC6570](https://datatracker.ietf.org/doc/html/rfc6570#autoid-20), which allows [RFC3986's reserved character set](https://datatracker.ietf.org/doc/html/rfc3986#autoid-13), as well as percent-encoded triples, to pass through unchanged, while still percent-encoding all other disallowed characters (including `%` outside of percent-encoded triples). Applications are still responsible for percent-encoding reserved characters that are [not allowed in the query string](https://datatracker.ietf.org/doc/html/rfc3986#autoid-24) (`[`, `]`, `#`), or have a special meaning in `application/x-www-form-urlencoded` (`-`, `&`, `+`); see Appendices [C](#usingRFC6570Implementations) and [E](#percentEncodingAndFormMediaTypes) for details. This property only applies to parameters with an `in` value of `query`. The default value is `false`. schema | [Schema Object](#schemaObject) | The schema defining the type used for the parameter. example | Any | Example of the parameter's potential value; see [Working With Examples](#working-with-examples). examples | Map[ `string`, [Example Object](#exampleObject) \| [Reference Object](#referenceObject)] | Examples of the parameter's potential value; see [Working With Examples](#working-with-examples). +See also [Appendix C: Using RFC6570 Implementations](#usingRFC6570Implementations) for additional guidance. + ###### Fixed Fields and considerations for use with `content` For more complex scenarios, the [`content`](#parameterContent) property can define the media type and schema of the parameter, as well as give examples of its use. @@ -1739,10 +1741,12 @@ Field Name | Type | Description headers | Map[`string`, [Header Object](#headerObject) \| [Reference Object](#referenceObject)] | A map allowing additional information to be provided as headers, for example `Content-Disposition`. `Content-Type` is described separately and SHALL be ignored in this section. This property SHALL be ignored if the request body media type is not a `multipart`. style | `string` | Describes how a specific property value will be serialized depending on its type. See [Parameter Object](#parameterObject) for details on the [`style`](#parameterStyle) property. The behavior follows the same values as `query` parameters, including default values. This property SHALL be ignored if the request body media type is not `application/x-www-form-urlencoded` or `multipart/form-data`. If a value is explicitly defined, then the value of [`contentType`](#encodingContentType) (implicit or explicit) SHALL be ignored. explode | `boolean` | When this is true, property values of type `array` or `object` generate separate parameters for each value of the array, or key-value-pair of the map. For other types of properties this property has no effect. When [`style`](#encodingStyle) is `form`, the default value is `true`. For all other styles, the default value is `false`. This property SHALL be ignored if the request body media type is not `application/x-www-form-urlencoded` or `multipart/form-data`. If a value is explicitly defined, then the value of [`contentType`](#encodingContentType) (implicit or explicit) SHALL be ignored. -allowReserved | `boolean` | Determines whether the parameter value SHOULD allow reserved characters, as defined by [RFC3986](https://tools.ietf.org/html/rfc3986#section-2.2) `:/?#[]@!$&'()*+,;=` to be included without percent-encoding. The default value is `false`. This property SHALL be ignored if the request body media type is not `application/x-www-form-urlencoded` or `multipart/form-data`. If a value is explicitly defined, then the value of [`contentType`](#encodingContentType) (implicit or explicit) SHALL be ignored. +allowReserved | `boolean` | When this is true, parameter values are serialized using reserved expansion, as defined by [RFC6570](https://datatracker.ietf.org/doc/html/rfc6570#autoid-20), which allows [RFC3986's reserved character set](https://datatracker.ietf.org/doc/html/rfc3986#autoid-13), as well as percent-encoded triples, to pass through unchanged, while still percent-encoding all other disallowed characters (including `%` outside of percent-encoded triples). Applications are still responsible for percent-encoding reserved characters that are [not allowed in the query string](https://datatracker.ietf.org/doc/html/rfc3986#autoid-24) (`[`, `]`, `#`), or have a special meaning in `application/x-www-form-urlencoded` (`-`, `&`, `+`); see Appendices [C](#usingRFC6570Implementations) and [E](#percentEncodingAndFormMediaTypes) for details. This property only applies to parameters with an `in` value of `query`. The default value is `false`. This property SHALL be ignored if the request body media type is not `application/x-www-form-urlencoded` or `multipart/form-data`. If a value is explicitly defined, then the value of [`contentType`](#encodingContentType) (implicit or explicit) SHALL be ignored. This object MAY be extended with [Specification Extensions](#specificationExtensions). +See also [Appendix C: Using RFC6570 Implementations](#usingRFC6570Implementations) for additional guidance. + ##### Encoding Object Example `multipart/form-data` allows for binary parts: @@ -4037,6 +4041,243 @@ Version | Date | Notes ## Appendix C: Using RFC6570 Implementations +Serialization is defined in terms of RFC6570 URI Templates in two scenarios: + +Object | Condition +------ | --------- +[Parameter Object](#parameterObject) | When `schema` is present +[Encoding Object](#encodingObject) | When encoding for `application/x-www-form-urlencoded` and any of `style`, `explode`, or `allowReserved` are used + +Implementations of this specification MAY use an implementation of RFC6570 to perform variable expansion, however, some caveats apply. + +Note that when using `style: form` RFC6570 expansion to produce an `application/x-www-form-urlencoded` HTTP message body, it is necessary to remove the `?` prefix that is produced to satisfy the URI query string syntax. + +Note also that not all RFC6570 implementations support all four levels of operators, all of which are needed to fully support the OpenAPI Specification's usage. +Using an implementation with a lower level of support will require additional manual construction of URI Templates to work around the limitations. + +### Equivalences Between Fields and RFC6570 Operators + +Certain field values translate to RFC6570 operators (or lack thereof): + +field | value | equivalent +----- | ----- | ---------- +style | simple | _n/a_ +style | matrix | `;` prefix operator +style | label | `.` prefix operator +style | form | `?` prefix operator +allowReserved | `false` | _n/a_ +allowReserved | `true` | `+` prefix operator +explode | `false` | _n/a_ +explode | `true` | `*` modifier suffix + +Multiple `style: form` parameters are equivalent to a single RFC6570 [variable list](https://www.rfc-editor.org/rfc/rfc6570#section-2.2) using the `?` prefix operator: + +```YAML +parameters: +- name: foo + in: query + schema: + type: object + explode: true +- name: bar + in: query + schema: + type: string +``` + +This example is equivalent to RFC6570's `{?foo*,bar}`, and ***NOT*** `{?foo*}{&bar}`, which is problematic because if `foo` is not defined, the result will be an invalid URI. +The `&` prefix operator has no equivalent in the Parameter Object. + +Note that RFC6570 does not specify behavior for compound values beyond the single level addressed by `explode`. The results of using objects or arrays where no behavior is clearly specified for them is implementation-defined. + +### Non-RFC6570 Field Values and Combinations + +Configurations with no direct RFC6570 equivalent SHOULD also be handled according to RFC6570. +Implementations MAY create a properly delimited URI Template with variables for individual names and values using RFC6570 regular or reserved expansion (based on `allowReserved`). + +This includes: + * the styles `pipeDelimited`, `spaceDelimited`, and `deepObject`, which have no equivalents at all + * the combination of the style `form` with `allowReserved: true`, which is not allowed because only one prefix operator can be used at a time + * any parameter name that is not a legal RFC6570 variable name + +The Parameter Object's `name` field has a much more permissive syntax than [RFC6570 variable name syntax](https://www.rfc-editor.org/rfc/rfc6570#section-2.3). +A parameter name that includes characters outside of the allowed RFC6570 variable character set MUST be percent-encoded before it can be used in a URI Template. + +### Examples + +Let's say we want to use the following data in a form query string, where `formulas` is exploded, and `words` is not: + +```YAML +formulas: + a: x+y + b: x/y + c: x^y +words: +- math +- is +- fun +``` + +#### RFC6570-Equivalent Expansion + +This array of parameter objects uses regular `style: form` expansion, fully supported by RFC6570: + +```YAML +parameters: +- name: formulas + in: query + schema: + type: object + additionalProperties: + type: string + explode: true +- name: words + in: query + schema: + type: array + items: + type: string +``` + +This translates to the following URI Template: + +```urlencoded +{?formulas*,words} +``` + +when expanded with the data given earlier, we get: + +```urlencoded +?a=x%2By&b=x%2Fy&c=x%5Ey&words=math,is,fun +``` + +#### Expansion With Non-RFC6570-Supported Options + +But now let's say that (for some reason), we really want that `/` in the `b` formula to show up as-is in the query string, and we want our words to be space-separated like in a written phrase. +To do that, we'll add `allowReserved: true` to `formulas`, and change to `style: spaceDelimited` for `words`: + +```YAML +parameters: +- name: formulas + in: query + schema: + type: object + additionalProperties: + type: string + explode: true + allowReserved: true +- name: words + in: query + style: spaceDelimited + schema: + type: array + items: + type: string +``` + +We can't combine the `?` and `+` RFC6570 prefixes, and there's no way with RFC6570 to replace the `,` separator with a space character. +So we need to restructure the data to fit a manually constructed URI Template that passes all of the pieces through the right sort of expansion. + +Here is one such template, using a made-up convention of `words.0` for the first entry in the words value, `words.1` for the second. + +```urlencoded +?a={+a}&b={+b}&c={+c}&words={words.0} {words.1} {words.2} +``` + +RFC6570 [mentions](https://www.rfc-editor.org/rfc/rfc6570.html#section-2.4.2) the use of `.` "to indicate name hierarchy in substructures," but does not define any specific naming convention or behavior for it. +Since the `.` usage is not automatic, we'll need to construct an appropriate input structure for this new template. + +We'll also need to pre-process the values for `formulas` because while `/` and most other reserved characters are allowed in the query string by RFC3986, `[`, `]`, and `#` [are not](https://datatracker.ietf.org/doc/html/rfc3986#appendix-A), and `&`, `=`, and `+` all have [special behavior](https://www.rfc-editor.org/rfc/rfc1866#section-8.2.1) in the `application/x-www-form-urlencoded` format, which is what we are using in the query string. + +Setting `allowReserved: true` does _not_ make reserved characters that are not allowed in URIs allowed, it just allows them to be _passed through expansion unchanged._ +Therefore, any tooling still needs to percent-encode those characters because reserved expansion will not do it, but it _will_ leave the percent-encoded triples unchanged. +See also [Appendix E](#to indicate name hierarchy in substructures) for further guidance on percent-encoding and form media types, including guidance on handling the delimiter characters for `spaceDelimited`, `pipeDelimited`, and `deepObject` in parameter names and values. + +So here is our data structure that arranges the names and values to suit the template above, where values for `formulas` have `[]#&=+` pre-percent encoded (although only `+` appears in this example): + +```YAML +a: x%2By +b: x/y +c: x^y +words.0: math +words.1: is +words.2: fun +``` + +Expanding our manually assembled template with our restructured data yields the following query string: + +```urlencoded +?a=x%2By&b=x/y&c=x%5Ey&words=math%20is%20fun +``` +The `/` and the pre-percent-encoded `%2B` have been left alone, but the disallowed `^` character (inside a value) and space characters (in the template but outside of the expanded variables) were percent-encoded. + +#### Undefined Values and Manual URI Template Construction + +Care must be taken when manually constructing templates to handle the values that [RFC6570 considers to be _undefined_](https://datatracker.ietf.org/doc/html/rfc6570#section-2.3) correctly: + +```YAML +formulas: {} +words: +- hello +- world +``` + +Using this data with our original RFC6570-friendly URI Template, `{?formulas*,words}`, produces the following: + + +```urlencoded +?words=hello,world +``` + +This means that the manually constructed URI Template and restructured data need to leave out the `formulas` object entirely so that the `words` parameter is the first and only parameter in the query string. + +Restructured data: + +```YAML +words.0: hello +words.1: world +``` + +Manually constructed URI Template: + +```urlencoded +?words={words.0} {words.1} +``` + +Result: + +```urlencoded +?words=hello%20world +``` + +#### Illegal Variable Names as Parameter Names +In this example, the heart emoji is not legal in URI Template names (or URIs): + +```YAML +parameters: +- name: ❤️ + in: query + schema: + type: string +``` + +We can't just pass `❤️: love!` to an RFC6570 implementation. +Instead, we have to pre-percent-encode the name (which is a six-octet UTF-8 sequence) in both the data and the URI Template: + +```YAML +"%E2%9D%A4%EF%B8%8F": love! +``` + +```urlencoded +{?%E2%9D%A4%EF%B8%8F} +``` + +This will expand to the result: + +```urlencoded +?%E2%9D%A4%EF%B8%8F=love%21 +``` + ## Appendix D: Serializing Headers and Cookies ## Appendix E: Percent-Encoding and Form Media Types From 0adeccdf4449f2cc45f6658f58c184389cc2c558 Mon Sep 17 00:00:00 2001 From: "Henry H. Andrews" Date: Fri, 14 Jun 2024 15:41:59 -0700 Subject: [PATCH 05/37] Fix stray mentions of parameters (3.1.1 port of 3911 1/2) --- versions/3.1.1.md | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/versions/3.1.1.md b/versions/3.1.1.md index 3b4c204107..504b212c44 100644 --- a/versions/3.1.1.md +++ b/versions/3.1.1.md @@ -1741,7 +1741,7 @@ Field Name | Type | Description headers | Map[`string`, [Header Object](#headerObject) \| [Reference Object](#referenceObject)] | A map allowing additional information to be provided as headers, for example `Content-Disposition`. `Content-Type` is described separately and SHALL be ignored in this section. This property SHALL be ignored if the request body media type is not a `multipart`. style | `string` | Describes how a specific property value will be serialized depending on its type. See [Parameter Object](#parameterObject) for details on the [`style`](#parameterStyle) property. The behavior follows the same values as `query` parameters, including default values. This property SHALL be ignored if the request body media type is not `application/x-www-form-urlencoded` or `multipart/form-data`. If a value is explicitly defined, then the value of [`contentType`](#encodingContentType) (implicit or explicit) SHALL be ignored. explode | `boolean` | When this is true, property values of type `array` or `object` generate separate parameters for each value of the array, or key-value-pair of the map. For other types of properties this property has no effect. When [`style`](#encodingStyle) is `form`, the default value is `true`. For all other styles, the default value is `false`. This property SHALL be ignored if the request body media type is not `application/x-www-form-urlencoded` or `multipart/form-data`. If a value is explicitly defined, then the value of [`contentType`](#encodingContentType) (implicit or explicit) SHALL be ignored. -allowReserved | `boolean` | When this is true, parameter values are serialized using reserved expansion, as defined by [RFC6570](https://datatracker.ietf.org/doc/html/rfc6570#autoid-20), which allows [RFC3986's reserved character set](https://datatracker.ietf.org/doc/html/rfc3986#autoid-13), as well as percent-encoded triples, to pass through unchanged, while still percent-encoding all other disallowed characters (including `%` outside of percent-encoded triples). Applications are still responsible for percent-encoding reserved characters that are [not allowed in the query string](https://datatracker.ietf.org/doc/html/rfc3986#autoid-24) (`[`, `]`, `#`), or have a special meaning in `application/x-www-form-urlencoded` (`-`, `&`, `+`); see Appendices [C](#usingRFC6570Implementations) and [E](#percentEncodingAndFormMediaTypes) for details. This property only applies to parameters with an `in` value of `query`. The default value is `false`. This property SHALL be ignored if the request body media type is not `application/x-www-form-urlencoded` or `multipart/form-data`. If a value is explicitly defined, then the value of [`contentType`](#encodingContentType) (implicit or explicit) SHALL be ignored. +allowReserved | `boolean` | When this is true, parameter values are serialized using reserved expansion, as defined by [RFC6570](https://datatracker.ietf.org/doc/html/rfc6570#autoid-20), which allows [RFC3986's reserved character set](https://datatracker.ietf.org/doc/html/rfc3986#autoid-13), as well as percent-encoded triples, to pass through unchanged, while still percent-encoding all other disallowed characters (including `%` outside of percent-encoded triples). Applications are still responsible for percent-encoding reserved characters that are [not allowed in the query string](https://datatracker.ietf.org/doc/html/rfc3986#autoid-24) (`[`, `]`, `#`), or have a special meaning in `application/x-www-form-urlencoded` (`-`, `&`, `+`); see Appendices [C](#usingRFC6570Implementations) and [E](#percentEncodingAndFormMediaTypes) for details. The default value is `false`. This property SHALL be ignored if the request body media type is not `application/x-www-form-urlencoded` or `multipart/form-data`. If a value is explicitly defined, then the value of [`contentType`](#encodingContentType) (implicit or explicit) SHALL be ignored. This object MAY be extended with [Specification Extensions](#specificationExtensions). From 707a25d1083420dc5e6560746e113191eb9ef408 Mon Sep 17 00:00:00 2001 From: "Henry H. Andrews" Date: Wed, 22 May 2024 15:24:19 -0700 Subject: [PATCH 06/37] Appendix on converting data types to strings (3.1.1 port of 3840) It's very unclear how numbers, booleans, and other non-UTF-8-string values are converted to strings, particularly for the form media types. This adds a brief appendix that acknowledges the lack of standardization, and points to resources for the few cases that do have specifications. It highlights concerns with relying on certain JSON Schema keywords or values for serialization, and suggests defining schemas of type string and requiring applications to perform the conversion prior to schema validation as a way to control the results. This also clarifies that schema validation occurs before serialization. Also add note about RFC6570 type conversions. The spec doesn't address it, but implementations often have their own rules. --- versions/3.1.1.md | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) diff --git a/versions/3.1.1.md b/versions/3.1.1.md index 504b212c44..c1271960dc 100644 --- a/versions/3.1.1.md +++ b/versions/3.1.1.md @@ -1158,6 +1158,7 @@ There are four possible parameter locations specified by the `in` field: The rules for serialization of the parameter are specified in one of two ways. Parameter Objects MUST include either a `content` field or a `schema` field, but not both. +See [Appendix B](#dataTypeConversion) for a discussion of converting values of various types to string representations. ###### Common Fixed Fields @@ -1733,6 +1734,7 @@ An `encoding` attribute is introduced to give you control over the serialization #### Encoding Object A single encoding definition applied to a single schema property. +See [Appendix B](#dataTypeConversion) for a discussion of converting values of various types to string representations. ##### Fixed Fields Field Name | Type | Description @@ -4039,6 +4041,32 @@ Version | Date | Notes ## Appendix B: Data Type Conversion +Serializing typed data to plain text, which can occur in `text/plain` message bodies or `multipart` parts, as well as in the `application/x-www-form-urlencoded` format in either URL query strings or message bodies, involves significant implementation- or application-defined behavior. + +Schema Objects validate data based on the [JSON Schema data model](https://datatracker.ietf.org/doc/html/draft-wright-json-schema-00#section-4.2), which only recognizes four primitive data types: strings (which are [only broadly interoperable as UTF-8](https://datatracker.ietf.org/doc/html/rfc7159#section-8.1)), numbers, booleans, and `null`. +Notably, integers are not a distinct type from other numbers, with `type: integer` being a convenience defined mathematically, rather than based on the presence or absence of a decimal point in any string representation. + +The [Parameter Object](#parameterObject) and [Encoding Object](#encodingObject) offer features to control how to arrange values from array or object types. +They can also be used to control how strings are further encoded to avoid reserved or illegal characters. +However, there is no general-purpose specification for converting schema-validated non-UTF-8 primitive data types (or entire arrays or objects) to strings. + +Two cases do offer standards-based guidance: + +* [RFC3987 §3.1](https://datatracker.ietf.org/doc/html/rfc3987#section-3.1) provides guidance for converting non-Unicode strings to UTF-8, particularly in the context of URIs (and by extension, the form media types which use the same encoding rules) +* [RFC6570 §2.3](https://www.rfc-editor.org/rfc/rfc6570#section-2.3) specifies which values, including but not limited to `null`, are considered _undefined_ and therefore treated specially in the expansion process when serializing based on that specification + +Implementations of RFC6570 often have their own conventions for converting non-string values, but these are implementation-specific and not defined by the RFC itself. +This is one reason for the OpenAPI Specification to leave these conversions as implementation-defined: It allows using RFC6570 implementations regardless of how they choose to perform the conversions. + +To control the serialization of numbers, booleans, and `null` (or other values RFC6570 deems to be undefined) more precisely, schemas can be defined as `type: string` and constrained using `pattern`, `enum`, `format`, and other keywords to communicate how applications must pre-convert their data prior to schema validation. +The resulting strings would not require any further type conversion. + +The `format` keyword can assist in serialization. +Some formats (such as `date-time` or `byte`) are unambiguous, while others (such as [`decimal`](https://spec.openapis.org/registry/format/decimal.html) in the [Format Registry](https://spec.openapis.org/registry/format/)) are less clear. +However, care must be taken with `format` to ensure that the specific formats are supported by all relevant tools as unrecognized formats are ignored. + +Requiring input as pre-formatted, schema-validated strings also improves round-trip interoperability as not all programming languages and environments support the same data types. + ## Appendix C: Using RFC6570 Implementations Serialization is defined in terms of RFC6570 URI Templates in two scenarios: From 605d329b721d3ee64b702c77a3928845bcb79ad1 Mon Sep 17 00:00:00 2001 From: "Henry H. Andrews" Date: Wed, 22 May 2024 17:38:57 -0700 Subject: [PATCH 07/37] Warnings for header and cookie serialization (3.1.1 port of 3841) This makes serializing cookie paramters and most header parameters with `schema` and `style` NOT RECOMMENDED. It is not clear that any `schema`-based serialization for cookies will produce a correct value (although the reason is sufficiently obscure that many implementations might ignore it and produce cookie-compliant output anyway). With headers, there are numerous pitfalls and only the simplest scenarios will work properly, although perhaps the warning here could be reworded to emphasize the safe scenarios more clearly. The details are relegated to an appendix, because truly, most people will not want to know. But recommending against syntactically legal configurations really does need to be explained in the spec. Also, don't use - in: header name: Cookie Because... yeah. --- versions/3.1.1.md | 27 +++++++++++++++++++++++++-- 1 file changed, 25 insertions(+), 2 deletions(-) diff --git a/versions/3.1.1.md b/versions/3.1.1.md index c1271960dc..cc9be34aa3 100644 --- a/versions/3.1.1.md +++ b/versions/3.1.1.md @@ -1153,7 +1153,6 @@ There are four possible parameter locations specified by the `in` field: * header - Custom headers that are expected as part of the request. Note that [RFC7230](https://tools.ietf.org/html/rfc7230#page-22) states header names are case insensitive. * cookie - Used to pass a specific cookie value to the API. - ##### Fixed Fields The rules for serialization of the parameter are specified in one of two ways. @@ -1173,12 +1172,16 @@ Field Name | Type | Description deprecated | `boolean` | Specifies that a parameter is deprecated and SHOULD be transitioned out of usage. Default value is `false`. allowEmptyValue | `boolean` | If `true`, clients MAY pass a zero-length string value in place of parameters that would otherwise be omitted entirely, which the server SHOULD interpret as the parameter being unused. Default value is `false`. If [`style`](#parameterStyle) is used, and if behavior is `n/a` (cannot be serialized), the value of `allowEmptyValue` SHALL be ignored. Interactions between this field and the parameter's [Schema Object](#schemaObject) are implementation-defined. This field is valid only for `query` parameters. Use of this property is NOT RECOMMENDED, and it is likely to be removed in a later revision. +Note that while `"Cookie"` as a `name` is not forbidden with `in: header`, the effect of defining a cookie parameter that way is undefined; use `in: cookie` instead. + ###### Fixed Fields for use with `schema` For simpler scenarios, a [`schema`](#parameterSchema) and [`style`](#parameterStyle) can describe the structure and syntax of the parameter. When `example` or `examples` are provided in conjunction with the `schema` object, the example SHOULD match the specified schema and follow the prescribed serialization strategy for the parameter. The `example` and `examples` fields are mutually exclusive, and if either is present it SHALL _override_ any `example` in the schema. +Serializing with `schema` is NOT RECOMMENDED for `in: cookie` parameters, `in: header` parameters that use HTTP header parameters (name=value pairs following a `;`) in their values, or `in: header` parameters where values might have non-URL-safe characters; see [Appendix D](#serializingHeadersAndCookies) for details. + Field Name | Type | Description ---|:---:|--- style | `string` | Describes how the parameter value will be serialized depending on the type of the parameter value. Default values (based on value of `in`): for `query` - `form`; for `path` - `simple`; for `header` - `simple`; for `cookie` - `form`. @@ -1190,9 +1193,10 @@ Field Name | Type | Description See also [Appendix C: Using RFC6570 Implementations](#usingRFC6570Implementations) for additional guidance. -###### Fixed Fields and considerations for use with `content` +###### Fixed Fields for use with `content` For more complex scenarios, the [`content`](#parameterContent) property can define the media type and schema of the parameter, as well as give examples of its use. +Using `content` with a `text/plain` media type is RECOMMENDED for `in: header` and `in: cookie` parameters where the `schema` strategy is not appropriate. Field Name | Type | Description ---|:---:|--- @@ -4308,4 +4312,23 @@ This will expand to the result: ## Appendix D: Serializing Headers and Cookies +RFC6570's percent-encoding behavior is not always appropriate for `in: header` and `in: cookie` parameters. +In many cases, it is more appropriate to use `content` with a media type such as `text/plain` and require the application to assemble the correct string. + +For both cookies ([RFC6265](https://www.rfc-editor.org/rfc/rfc6265)) and HTTP headers using the structured fields ([RFC8941](https://www.rfc-editor.org/rfc/rfc8941)) syntax, non-ASCII content is handled using base64 encoding (`format: byte`). +Note that the standard base64 encoding alphabet includes non-URL-safe characters that are percent-encoded by RFC6570 expansion; serializing values through both encodings is NOT RECOMMENDED. + +Most HTTP headers predate the structured field syntax, and a comprehensive assessment of their syntax and encoding rules is well beyond the scope of this specification. +While [RFC8187](https://www.rfc-editor.org/rfc/rfc8187) recommends percent-encoding HTTP field (header or trailer) parameters, these parameters appear after a `;` character. +With `style: simple`, that delimiter would itself be percent-encoded, violating the general HTTP field syntax. + +Using `style: form` with `in: cookie` is ambiguous for a single value, and incorrect for multiple values. +This is true whether the multiple values are the result of using `explode: true` or not. + +This style is specified to be equivalent to RFC6570 form expansion which includes the `?` character (see Appendix C for more details), which is not part of the cookie syntax. +However, examples of this style in past versions of this specification have not included the `?` prefix, suggesting that the comparison is not exact. +Because implementations that rely on an RFC6570 implementation and those that perform custom serialization based on the style example will produce different results, it is implementation-defined as to which of the two results is correct. + +For multiple values, `style: form` is always incorrect as name=value pairs in cookies are delimited by `; ` (a semicolon followed by a space character) rather than `&`. + ## Appendix E: Percent-Encoding and Form Media Types From 21af3bb39850ca1e9afbb80783e120e9d1901fb8 Mon Sep 17 00:00:00 2001 From: "Henry H. Andrews" Date: Sun, 9 Jun 2024 10:16:49 -0700 Subject: [PATCH 08/37] Add Security Considerations (3.1.1 port of 3894) This adds the previously standalone security considerations document as a top-level section just before the appendices. --- versions/3.1.1.md | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) diff --git a/versions/3.1.1.md b/versions/3.1.1.md index cc9be34aa3..96f428e27f 100644 --- a/versions/3.1.1.md +++ b/versions/3.1.1.md @@ -4021,6 +4021,31 @@ Two examples of this: 1. The [Paths Object](#pathsObject) MAY be present but empty. It may be counterintuitive, but this may tell the viewer that they got to the right place, but can't access any documentation. They would still have access to at least the [Info Object](#infoObject) which may contain additional information regarding authentication. 2. The [Path Item Object](#pathItemObject) MAY be empty. In this case, the viewer will be aware that the path exists, but will not be able to see any of its operations or parameters. This is different from hiding the path itself from the [Paths Object](#pathsObject), because the user will be aware of its existence. This allows the documentation provider to finely control what the viewer can see. +## Security Considerations + +### OpenAPI Document Formats + +OpenAPI documents use JSON, YAML, and JSON Schema, and therefore share their security considerations: +- [JSON](https://www.iana.org/assignments/media-types/application/json) +- [YAML](https://www.iana.org/assignments/media-types/application/yaml) +- [JSON Schema Core](https://json-schema.org/draft/2020-12/json-schema-core#section-13) +- [JSON Schema Validation](https://json-schema.org/draft/2020-12/json-schema-validation#name-security-considerations) + +### Tooling and Usage Scenarios + +In addition, OpenAPI documents are processed by a wide variety of tooling for numerous different purposes, such as client code generation, documentation generation, server side routing, and API testing. OpenAPI document authors must consider the risks of the scenarios where the OpenAPI document may be used. + +### Security Schemes + +An OpenAPI document describes the security schemes used to protect the resources it defines. The security schemes available offer varying degrees of protection. Factors such as the sensitivity of the data and the potential impact of a security breach should guide the selection of security schemes for the API resources. Some security schemes, such as basic auth and OAuth Implicit flow, are supported for compatibility with existing APIs. However, their inclusion in OpenAPI does not constitute an endorsement of their use, particularly for highly sensitive data or operations. + +### Handling External Resources + +OpenAPI documents may contain references to external resources that may be dereferenced automatically by consuming tools. External resources may be hosted on different domains that may be untrusted. References in an OpenAPI document, or across OpenAPI documents may cause a cycle. Tooling must detect and handle cycles to prevent resource exhaustion. + +### Markdown and HTML Sanitization + +Certain properties allow the use of Markdown which can contain HTML including script. It is the responsibility of tooling to appropriately sanitize the Markdown. ## Appendix A: Revision History From 9f2997aa5b8fd6754b67aef4aa7246e728e87dfa Mon Sep 17 00:00:00 2001 From: "Henry H. Andrews" Date: Mon, 27 May 2024 14:04:59 -0700 Subject: [PATCH 09/37] Link to the Learn and Spec sites (3.1.1 port of 3861 1/11) Guide readers to supplemental documentation, examples, related specificatioins, and extension registries. These sites answer many questions that otherwise get raised as GitHub issues. --- versions/3.1.1.md | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/versions/3.1.1.md b/versions/3.1.1.md index 96f428e27f..53faf2933c 100644 --- a/versions/3.1.1.md +++ b/versions/3.1.1.md @@ -12,6 +12,10 @@ The OpenAPI Specification (OAS) defines a standard, language-agnostic interface An OpenAPI definition can then be used by documentation generation tools to display the API, code generation tools to generate servers and clients in various programming languages, testing tools, and many other use cases. +For examples of OpenAPI usage and additional documentation, please visit [learn.openapis.org](https://learn.openapis.org/). + +For extension registries and other specifications published by the OpenAPI Initiative, please visit [spec.openapis.org](https://spec.openapis.org/) + ## Table of Contents From a3ce61ab92d84726899bb263f49ffcc3dac6a6f9 Mon Sep 17 00:00:00 2001 From: "Henry H. Andrews" Date: Mon, 27 May 2024 14:10:42 -0700 Subject: [PATCH 10/37] Clarify "Schema" (3.1.1 port of 3861 2/11) --- versions/3.1.1.md | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/versions/3.1.1.md b/versions/3.1.1.md index 53faf2933c..2c12435c1f 100644 --- a/versions/3.1.1.md +++ b/versions/3.1.1.md @@ -322,6 +322,11 @@ Relative references in CommonMark hyperlinks are resolved in their rendered cont ### Schema +This section describes the structure of the OpenAPI Description format. +This text is the only normative description of the format. +A JSON Schema is hosted on [spec.openapis.org](https://spec.openapis.org) for informational purposes. +If the JSON Schema differs from this section, then this section MUST be considered authoritative. + In the following description, if a field is not explicitly **REQUIRED** or described with a MUST or SHALL, it can be considered OPTIONAL. #### OpenAPI Object From 35974ac5343f91e4a7e788781c89ca8bff8bc0dc Mon Sep 17 00:00:00 2001 From: "Henry H. Andrews" Date: Mon, 27 May 2024 14:17:21 -0700 Subject: [PATCH 11/37] Global HTTP case-(in)sensitivity rule (3.1.1 port of 3861 3/11) --- versions/3.1.1.md | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/versions/3.1.1.md b/versions/3.1.1.md index 2c12435c1f..22fbc2bd29 100644 --- a/versions/3.1.1.md +++ b/versions/3.1.1.md @@ -103,6 +103,11 @@ Some examples of possible media type definitions: The HTTP Status Codes are used to indicate the status of the executed operation. Status codes SHOULD be selected from the available status codes registered in the [IANA Status Code Registry](https://www.iana.org/assignments/http-status-codes/http-status-codes.xhtml). +##### HTTP and Case Sensitivity + +As most field names and values in the OpenAPI Specification are case-sensitive, this document endeavors to call out any case-insensitive names and values. +However, the case sensitivity of field names and values that map directly to HTTP concepts follow the case sensitivity rules of HTTP, even if this document does not make a note of every concept. + ##### Undefined and Implementation-Defined Behavior This specification deems certain situations to have either _undefined_ or _implementation-defined_ behavior. From d95ed15a146fe9fd718f41648bba543e70c5bc71 Mon Sep 17 00:00:00 2001 From: "Henry H. Andrews" Date: Mon, 27 May 2024 14:25:46 -0700 Subject: [PATCH 12/37] Improved description of XML examples (3.1.1 port of 3861 4/11) --- versions/3.1.1.md | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/versions/3.1.1.md b/versions/3.1.1.md index 22fbc2bd29..b58fc1f69d 100644 --- a/versions/3.1.1.md +++ b/versions/3.1.1.md @@ -3330,7 +3330,8 @@ This object MAY be extended with [Specification Extensions](#specificationExtens ##### XML Object Examples -The examples of the XML object definitions are included inside a property definition of a [Schema Object](#schemaObject) with a sample of the XML representation of it. +Each of the following examples represent the value of the `properties` keyword in a [Schema Object](#schemaObject) that is omitted for brevity. +The JSON and YAML representations of the `properties` value are followed by an example XML representation produced for the single property shown. ###### No XML Element From 35adc6e741d096dae217d314f725b1f14c2be11d Mon Sep 17 00:00:00 2001 From: "Henry H. Andrews" Date: Mon, 27 May 2024 14:45:49 -0700 Subject: [PATCH 13/37] Clarify CommonMark extensibility. (3.1.1 port of 3861 5/11) --- versions/3.1.1.md | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/versions/3.1.1.md b/versions/3.1.1.md index b58fc1f69d..8aa6b2c9e5 100644 --- a/versions/3.1.1.md +++ b/versions/3.1.1.md @@ -297,7 +297,7 @@ OAS < 3.1 | OAS 3.1 | Comments ### Rich Text Formatting Throughout the specification `description` fields are noted as supporting CommonMark markdown formatting. -Where OpenAPI tooling renders rich text it MUST support, at a minimum, markdown syntax as described by [CommonMark 0.27](https://spec.commonmark.org/0.27/). Tooling MAY choose to ignore some CommonMark features to address security concerns. +Where OpenAPI tooling renders rich text it MUST support, at a minimum, markdown syntax as described by [CommonMark 0.27](https://spec.commonmark.org/0.27/). Tooling MAY choose to implement extensions on top of CommonMark 0.27, and MAY choose to ignore some CommonMark or extension features to address security concerns. ### Relative References in API Description URIs From 6bb4cf419f4593aa7f9e9452914110ffde8c29c0 Mon Sep 17 00:00:00 2001 From: "Henry H. Andrews" Date: Mon, 27 May 2024 15:11:58 -0700 Subject: [PATCH 14/37] Add description to the Example Object (3.1.1 port of 3861 6/11) Co-authored-by: Lorna Jane Mitchell --- versions/3.1.1.md | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/versions/3.1.1.md b/versions/3.1.1.md index 8aa6b2c9e5..b0bc40e197 100644 --- a/versions/3.1.1.md +++ b/versions/3.1.1.md @@ -2131,6 +2131,11 @@ transactionCallback: #### Example Object +An object grouping an internal or external example value with basic `summary` and `description` metadata. +This object is typically used in properties named `examples` (plural), and is a [referenceable](#referenceObject) alternative to older `example` (singular) fields that do not support referencing or metadata. + +Examples allow demonstration of the usage of properties, parameters and objects within OpenAPI. + ##### Fixed Fields Field Name | Type | Description ---|:---:|--- From 1da61dd0b7fb0d0b22842f89188350fd193a2003 Mon Sep 17 00:00:00 2001 From: "Henry H. Andrews" Date: Mon, 3 Jun 2024 10:33:37 -0700 Subject: [PATCH 15/37] Mention the format registry in the data types section (3.1.1 port of 3861 7/11) Co-authored-by: Ralf Handl --- versions/3.1.1.md | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/versions/3.1.1.md b/versions/3.1.1.md index b0bc40e197..0ad36b4c95 100644 --- a/versions/3.1.1.md +++ b/versions/3.1.1.md @@ -246,7 +246,9 @@ Models are defined using the [Schema Object](#schemaObject), which is a superset As defined by the [JSON Schema Validation specification](https://tools.ietf.org/html/draft-bhutton-json-schema-validation-00#section-7.3), data types can have an optional modifier property: `format`. As described in that specification, `format` is treated as a non-validating annotation by default; the ability to validate `format` varies across implementations. -OAS defines additional formats to provide fine detail for primitive data types. +The OpenAPI Initiative also hosts a [Format Registry](https://spec.openapis.org/registry/format/) for formats defined by OAS users and other specifications. Support for any registered format is strictly OPTIONAL, and support for one registered format does not imply support for any others. + +Types that are not accompanied by a `format` property follow the type definition in the JSON Schema. Tools that do not recognize a specific `format` MAY default back to the `type` alone, as if the `format` is not specified. The formats defined by the OAS are: From c37898413904f13a686d91e1f1b8d245332b1aaf Mon Sep 17 00:00:00 2001 From: "Henry H. Andrews" Date: Tue, 4 Jun 2024 08:28:05 -0700 Subject: [PATCH 16/37] Note extension registry in extensions section. (3.1.1 port of 3861 8/11) --- versions/3.1.1.md | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/versions/3.1.1.md b/versions/3.1.1.md index 0ad36b4c95..b068014f6a 100644 --- a/versions/3.1.1.md +++ b/versions/3.1.1.md @@ -4027,9 +4027,14 @@ The extensions properties are implemented as patterned fields that are always pr Field Pattern | Type | Description ---|:---:|--- -^x- | Any | Allows extensions to the OpenAPI Schema. The field name MUST begin with `x-`, for example, `x-internal-id`. Field names beginning `x-oai-` and `x-oas-` are reserved for uses defined by the [OpenAPI Initiative](https://www.openapis.org/). The value can be `null`, a primitive, an array or an object. +^x- | Any | Allows extensions to the OpenAPI Schema. The field name MUST begin with `x-`, for example, `x-internal-id`. Field names beginning `x-oai-` and `x-oas-` are reserved for uses defined by the [OpenAPI Initiative](https://www.openapis.org/). The value can be any valid JSON format value (`null`, a primitive, an array or an object.) -The extensions may or may not be supported by the available tooling, but those may be extended as well to add requested support (if tools are internal or open-sourced). +The OpenAPI Initiative maintains several [extension registries](https://spec.openapis.org/registry/index.html), including registries for [individual extension keywords](https://spec.openapis.org/registry/extension/) and [extension keyword namespaces](https://spec.openapis.org/registry/namespace/). + +Extensions are one of the best ways to prove the viability of proposed additions to the specification. +It is therefore RECOMMENDED that implementations be designed for extensibility to support community experimentation. + +Support for any one extension is OPTIONAL, and support for one extension does not imply support for others. ### Security Filtering From 2846e7e31d95a2f6cc292541e41d8c369b8b9d4a Mon Sep 17 00:00:00 2001 From: "Henry H. Andrews" Date: Wed, 5 Jun 2024 11:28:32 -0700 Subject: [PATCH 17/37] Warn of interop issues w/Markdown extensions (3.1.1 port of 3861 9/11) Thanks to @lornajane for the review feedback. --- versions/3.1.1.md | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/versions/3.1.1.md b/versions/3.1.1.md index b068014f6a..e52b3790ae 100644 --- a/versions/3.1.1.md +++ b/versions/3.1.1.md @@ -299,7 +299,11 @@ OAS < 3.1 | OAS 3.1 | Comments ### Rich Text Formatting Throughout the specification `description` fields are noted as supporting CommonMark markdown formatting. -Where OpenAPI tooling renders rich text it MUST support, at a minimum, markdown syntax as described by [CommonMark 0.27](https://spec.commonmark.org/0.27/). Tooling MAY choose to implement extensions on top of CommonMark 0.27, and MAY choose to ignore some CommonMark or extension features to address security concerns. +Where OpenAPI tooling renders rich text it MUST support, at a minimum, markdown syntax as described by [CommonMark 0.27](https://spec.commonmark.org/0.27/). Tooling MAY choose to ignore some CommonMark or extension features to address security concerns. + +While the framing of CommonMark 0.27 as a minimum requirement means that tooling MAY choose to implement extensions on top of it, note that any such extensions are by definition implementation-defined and will not be interoperable. +OpenAPI Description authors SHOULD consider how text using such extensions will be rendered by tools that offer only the minimum support. + ### Relative References in API Description URIs From 1cb900731526ee26ca590c35520f5752ca9342f1 Mon Sep 17 00:00:00 2001 From: "Henry H. Andrews" Date: Wed, 5 Jun 2024 11:41:16 -0700 Subject: [PATCH 18/37] Clarify version (Info Object) further (3.1.1 port of 3861 10/11) --- versions/3.1.1.md | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/versions/3.1.1.md b/versions/3.1.1.md index e52b3790ae..f131caa9e5 100644 --- a/versions/3.1.1.md +++ b/versions/3.1.1.md @@ -377,7 +377,7 @@ Field Name | Type | Description termsOfService | `string` | A URI for the Terms of Service for the API. This MUST be in the form of a URI. contact | [Contact Object](#contactObject) | The contact information for the exposed API. license | [License Object](#licenseObject) | The license information for the exposed API. -version | `string` | **REQUIRED**. The version of the OpenAPI document (which is distinct from the [OpenAPI Specification version](#oasVersion) or the API implementation version). +version | `string` | **REQUIRED**. The version of the OpenAPI document (which is distinct from the [OpenAPI Specification version](#oasVersion) or the version of API being described). This object MAY be extended with [Specification Extensions](#specificationExtensions). From 8423a9ed289d36b152f6f6eb1b74731a289a73d5 Mon Sep 17 00:00:00 2001 From: "Henry H. Andrews" Date: Sat, 8 Jun 2024 13:45:01 -0700 Subject: [PATCH 19/37] Clarify confusing use of YAML "JSON Schema" (3.1.1 port of 3861 11/11) When we mention YAML's "Failsafe schema" we give it a lower-case "schem", as the YAML documentatio does. We also prefix it with "YAML". However, we capitalize "Schema" in "JSON Schema ruleset", which (given how much JSON Schema is used in the OAS) is a jarring overlap with "JSON Schema". This change aligns "YAML JSON schema ruleset" with "YAML Failsafe ruleset" and explicitly calls out that it is unrelated to JSON Schema. --- versions/3.1.1.md | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/versions/3.1.1.md b/versions/3.1.1.md index f131caa9e5..64f20ba2f1 100644 --- a/versions/3.1.1.md +++ b/versions/3.1.1.md @@ -151,7 +151,7 @@ Patterned fields MUST have unique names within the containing object. In order to preserve the ability to round-trip between YAML and JSON formats, YAML version [1.2](https://yaml.org/spec/1.2/spec.html) is RECOMMENDED along with some additional constraints: -- Tags MUST be limited to those allowed by the [JSON Schema ruleset](https://yaml.org/spec/1.2/spec.html#id2803231). +- Tags MUST be limited to those allowed by [YAML's JSON schema ruleset](https://yaml.org/spec/1.2/spec.html#id2803231), which defines a subset of the YAML syntax and is unrelated to [JSON Schema](https://tools.ietf.org/html/draft-wright-json-schema-00). - Keys used in YAML maps MUST be limited to a scalar string, as defined by the [YAML Failsafe schema ruleset](https://yaml.org/spec/1.2/spec.html#id2802346). **Note:** While APIs may be defined by OpenAPI documents in either YAML or JSON format, the API request and response bodies and other content are not required to be JSON or YAML. From 95737d2226fc8da95ec8f8eae348257e3ebfbd3b Mon Sep 17 00:00:00 2001 From: "Henry H. Andrews" Date: Sat, 25 May 2024 15:26:11 -0700 Subject: [PATCH 20/37] Encoding Object content and header clarifications (3.1.1 port of 3857 1/4) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The Encoding Object's `contentType` field takes a comma-separated list of either regular or wildcared media types. These are the "two types" mentioned in the previous wording – "two" here did *not* refer to a limit on the number of entries in the list. These are not exactly media-type or media-range values, as both of those include parameters. This change also moves the hard-to-follow list of default values out of the individual field cell and into its own table. It takes `Content-Disposition` out of the header field's cell and instead explains limitations on header usage, and explains how `Content-Disposition` is used for encoding. This explanation includes a suggestion on how other `multipart` formats could be used with an Encoding Object, since their unnamed parts otherwise cannot be supported. Finally, it clarifies the interaction between `contentType` and the three fields imported from the Parameter Object, by aligning the recommended (but not, for compatibility reasons, required) behavior with guidance added in 3.1.0. --- versions/3.1.1.md | 39 +++++++++++++++++++++++++++++++++++++-- 1 file changed, 37 insertions(+), 2 deletions(-) diff --git a/versions/3.1.1.md b/versions/3.1.1.md index 64f20ba2f1..574ac156f5 100644 --- a/versions/3.1.1.md +++ b/versions/3.1.1.md @@ -1760,19 +1760,54 @@ An `encoding` attribute is introduced to give you control over the serialization A single encoding definition applied to a single schema property. See [Appendix B](#dataTypeConversion) for a discussion of converting values of various types to string representations. +Properties are correlated with `multipart` parts using the `name` parameter to `Content-Disposition: form-data`, and with `application/x-www-form-urlencoded` using the query string paramter names. +In both cases, their order is implementation-defined. + ##### Fixed Fields Field Name | Type | Description ---|:---:|--- -contentType | `string` | The Content-Type for encoding a specific property. Default value depends on the property type: for `object` - `application/json`; for `array` – the default is defined based on the inner type; for all other cases the default is `application/octet-stream`. The value can be a specific media type (e.g. `application/json`), a wildcard media type (e.g. `image/*`), or a comma-separated list of the two types. -headers | Map[`string`, [Header Object](#headerObject) \| [Reference Object](#referenceObject)] | A map allowing additional information to be provided as headers, for example `Content-Disposition`. `Content-Type` is described separately and SHALL be ignored in this section. This property SHALL be ignored if the request body media type is not a `multipart`. +contentType | `string` | The `Content-Type` for encoding a specific property. The value is a comma-separated list, each element of which is either a specific media type (e.g. `image/png`) or a wildcard media type (e.g. `image/*`). Default value depends on the property type as shown in the table below. +headers | Map[`string`, [Header Object](#headerObject) \| [Reference Object](#referenceObject)] | A map allowing additional information to be provided as headers. `Content-Type` is described separately and SHALL be ignored in this section. This property SHALL be ignored if the request body media type is not a `multipart`. style | `string` | Describes how a specific property value will be serialized depending on its type. See [Parameter Object](#parameterObject) for details on the [`style`](#parameterStyle) property. The behavior follows the same values as `query` parameters, including default values. This property SHALL be ignored if the request body media type is not `application/x-www-form-urlencoded` or `multipart/form-data`. If a value is explicitly defined, then the value of [`contentType`](#encodingContentType) (implicit or explicit) SHALL be ignored. explode | `boolean` | When this is true, property values of type `array` or `object` generate separate parameters for each value of the array, or key-value-pair of the map. For other types of properties this property has no effect. When [`style`](#encodingStyle) is `form`, the default value is `true`. For all other styles, the default value is `false`. This property SHALL be ignored if the request body media type is not `application/x-www-form-urlencoded` or `multipart/form-data`. If a value is explicitly defined, then the value of [`contentType`](#encodingContentType) (implicit or explicit) SHALL be ignored. allowReserved | `boolean` | When this is true, parameter values are serialized using reserved expansion, as defined by [RFC6570](https://datatracker.ietf.org/doc/html/rfc6570#autoid-20), which allows [RFC3986's reserved character set](https://datatracker.ietf.org/doc/html/rfc3986#autoid-13), as well as percent-encoded triples, to pass through unchanged, while still percent-encoding all other disallowed characters (including `%` outside of percent-encoded triples). Applications are still responsible for percent-encoding reserved characters that are [not allowed in the query string](https://datatracker.ietf.org/doc/html/rfc3986#autoid-24) (`[`, `]`, `#`), or have a special meaning in `application/x-www-form-urlencoded` (`-`, `&`, `+`); see Appendices [C](#usingRFC6570Implementations) and [E](#percentEncodingAndFormMediaTypes) for details. The default value is `false`. This property SHALL be ignored if the request body media type is not `application/x-www-form-urlencoded` or `multipart/form-data`. If a value is explicitly defined, then the value of [`contentType`](#encodingContentType) (implicit or explicit) SHALL be ignored. This object MAY be extended with [Specification Extensions](#specificationExtensions). +The default values for `contentType` are as follows: + +Property Type | Property Format | Default `contentType` +------------- | --------------- | --------------------- +`string` | `binary` | `application/octet-stream` +`string`, `number`, `integer`, or `boolean` | _n/a_ | `text/plain` +`object` | _n/a_ | `application/json` +`array` | _n/a_ | according to the `type` and `format` of the `items` schema + See also [Appendix C: Using RFC6570 Implementations](#usingRFC6570Implementations) for additional guidance. +###### Encoding `multipart` Media Types + +The `form-data` disposition and its `name` parameter are mandatory for `multipart/form-data` ([RFC7578 §4.2](https://www.rfc-editor.org/rfc/rfc7578.html#section-4.2)). +Array properties are handled by applying the same `name` to multiple parts, as is recommended by [RFC7578 §4.2](https://www.rfc-editor.org/rfc/rfc7578.html#section-4.3) for supplying multiple values per form field. +See [RFC7578 §5](https://www.rfc-editor.org/rfc/rfc7578.html#section-5) for guidance regarding non-ASCII part names. + +Various other `multipart` types, most notable `multipart/mixed` ([RFC2046 §5.1.3](https://www.rfc-editor.org/rfc/rfc2046.html#section-5.1.3)) neither require nor forbid specific `Content-Disposition` values, which means care must be taken to ensure that any values used are supported by all relevant software. +It is not currently possible to correlate schema properties with unnamed, ordered parts in media types such as `multipart/mixed`, but implementations MAY choose to support such types when `Content-Disposition: form-data` is used with a `name` parameter. + +Note that there are significant restrictions on what headers can be used with `multipart` media types in general ([RFC2046 §5.1](https://www.rfc-editor.org/rfc/rfc2046.html#section-5.1)) and `multi-part/form-data` in particular ([RFC7578 §4.8](https://www.rfc-editor.org/rfc/rfc7578.html#section-4.8)). + +Note also that `Content-Transfer-Encoding` is deprecated for `multipart/form-data` ([RFC7578 §4.7](https://www.rfc-editor.org/rfc/rfc7578.html#section-4.7)) where binary data is supported, as it is in HTTP. +Using `format: byte` for a multipart field is equivalent to setting `Content-Transfer-Encoding: base64`. +If `format: byte` is used along with setting a different `Content-Transfer-Encoding` value with the `headers` field, the result is undefined. + +###### Encoding the `application/x-www-form-urlencoded` Media Type + +The role of `contentType` with `application/x-www-form-urlencoded` request bodies was not described in detail in version 3.0.3 and earlier of this specification. +To match the intent of these fields and be compatible with version 3.1 of this specification, it is RECOMMENDED that whenever any of `style`, `explode`, or `allowReserved` are present with an explicit values, that the value of `contentType`, whether it is explicitly defined or has the default value, be ignored. +Likewise, if all three of those fields are absent, it is RECOMMENDED that they be ignored, and that encoding be based on `contentType` alone. + +This makes the presence of at least one of `style`, `explode`, or `allowReserved` with an explicit value equivalent to using `schema` with `in: query` Parameter Objects, and their absence the equivalent of using `content`, but with the media type specified in `contentType` rather than through a Media Type Object. + ##### Encoding Object Example `multipart/form-data` allows for binary parts: From 2d5f229701a618271b373bc4e560304f1c02d699 Mon Sep 17 00:00:00 2001 From: "Henry H. Andrews" Date: Wed, 5 Jun 2024 11:19:01 -0700 Subject: [PATCH 21/37] Reword default handling (3.1.1 port of 3857 2/4) Thanks to @notEthan for the comments! --- versions/3.1.1.md | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/versions/3.1.1.md b/versions/3.1.1.md index 574ac156f5..a6aa94ec71 100644 --- a/versions/3.1.1.md +++ b/versions/3.1.1.md @@ -1803,8 +1803,15 @@ If `format: byte` is used along with setting a different `Content-Transfer-Encod ###### Encoding the `application/x-www-form-urlencoded` Media Type The role of `contentType` with `application/x-www-form-urlencoded` request bodies was not described in detail in version 3.0.3 and earlier of this specification. -To match the intent of these fields and be compatible with version 3.1 of this specification, it is RECOMMENDED that whenever any of `style`, `explode`, or `allowReserved` are present with an explicit values, that the value of `contentType`, whether it is explicitly defined or has the default value, be ignored. -Likewise, if all three of those fields are absent, it is RECOMMENDED that they be ignored, and that encoding be based on `contentType` alone. +To match the intent of these fields and be compatible with version 3.1 of this specification, it is RECOMMENDED that whenever any of `style`, `explode`, or `allowReserved` are present with an explicit value: + +* The value of `contentType`, whether it is explicitly defined or has the default value, is to be ignored +* If any of `style`, `explode`, or `allowReserved` are _not_ present with explicit values, then they are to be treated as if they were present with their default values + +However, if all three of `style`, `explode`, and `allowReserved` fields are absent, it is RECOMMENDED that: + +* All three keywords are to be entirely ignored, rather than treated as having their default values +* Encoding is to be based on `contentType` alone, whether it is present with an explicit value or absent and treated as having its default value This makes the presence of at least one of `style`, `explode`, or `allowReserved` with an explicit value equivalent to using `schema` with `in: query` Parameter Objects, and their absence the equivalent of using `content`, but with the media type specified in `contentType` rather than through a Media Type Object. From f1e04f196162d13c2ca3b071cb1e19ee95c4bc14 Mon Sep 17 00:00:00 2001 From: "Henry H. Andrews" Date: Mon, 10 Jun 2024 16:25:51 -0700 Subject: [PATCH 22/37] Split up Encoding fields like Param/Header (3.1.1 port of 3857 3/4) This splits the Encoding Object's fixed fields table to make the usage more clear, and closer to how it is presented for the Parameter and Header Objects --- versions/3.1.1.md | 46 ++++++++++++++++++++++++++-------------------- 1 file changed, 26 insertions(+), 20 deletions(-) diff --git a/versions/3.1.1.md b/versions/3.1.1.md index a6aa94ec71..47757e4a9c 100644 --- a/versions/3.1.1.md +++ b/versions/3.1.1.md @@ -1763,14 +1763,14 @@ See [Appendix B](#dataTypeConversion) for a discussion of converting values of v Properties are correlated with `multipart` parts using the `name` parameter to `Content-Disposition: form-data`, and with `application/x-www-form-urlencoded` using the query string paramter names. In both cases, their order is implementation-defined. -##### Fixed Fields +###### Common Fixed Fields + +These fields MAY be used either with or without the RFC6570-style serialization fields defined in the next section below. + Field Name | Type | Description ---|:---:|--- contentType | `string` | The `Content-Type` for encoding a specific property. The value is a comma-separated list, each element of which is either a specific media type (e.g. `image/png`) or a wildcard media type (e.g. `image/*`). Default value depends on the property type as shown in the table below. headers | Map[`string`, [Header Object](#headerObject) \| [Reference Object](#referenceObject)] | A map allowing additional information to be provided as headers. `Content-Type` is described separately and SHALL be ignored in this section. This property SHALL be ignored if the request body media type is not a `multipart`. -style | `string` | Describes how a specific property value will be serialized depending on its type. See [Parameter Object](#parameterObject) for details on the [`style`](#parameterStyle) property. The behavior follows the same values as `query` parameters, including default values. This property SHALL be ignored if the request body media type is not `application/x-www-form-urlencoded` or `multipart/form-data`. If a value is explicitly defined, then the value of [`contentType`](#encodingContentType) (implicit or explicit) SHALL be ignored. -explode | `boolean` | When this is true, property values of type `array` or `object` generate separate parameters for each value of the array, or key-value-pair of the map. For other types of properties this property has no effect. When [`style`](#encodingStyle) is `form`, the default value is `true`. For all other styles, the default value is `false`. This property SHALL be ignored if the request body media type is not `application/x-www-form-urlencoded` or `multipart/form-data`. If a value is explicitly defined, then the value of [`contentType`](#encodingContentType) (implicit or explicit) SHALL be ignored. -allowReserved | `boolean` | When this is true, parameter values are serialized using reserved expansion, as defined by [RFC6570](https://datatracker.ietf.org/doc/html/rfc6570#autoid-20), which allows [RFC3986's reserved character set](https://datatracker.ietf.org/doc/html/rfc3986#autoid-13), as well as percent-encoded triples, to pass through unchanged, while still percent-encoding all other disallowed characters (including `%` outside of percent-encoded triples). Applications are still responsible for percent-encoding reserved characters that are [not allowed in the query string](https://datatracker.ietf.org/doc/html/rfc3986#autoid-24) (`[`, `]`, `#`), or have a special meaning in `application/x-www-form-urlencoded` (`-`, `&`, `+`); see Appendices [C](#usingRFC6570Implementations) and [E](#percentEncodingAndFormMediaTypes) for details. The default value is `false`. This property SHALL be ignored if the request body media type is not `application/x-www-form-urlencoded` or `multipart/form-data`. If a value is explicitly defined, then the value of [`contentType`](#encodingContentType) (implicit or explicit) SHALL be ignored. This object MAY be extended with [Specification Extensions](#specificationExtensions). @@ -1783,24 +1783,15 @@ Property Type | Property Format | Default `contentType` `object` | _n/a_ | `application/json` `array` | _n/a_ | according to the `type` and `format` of the `items` schema -See also [Appendix C: Using RFC6570 Implementations](#usingRFC6570Implementations) for additional guidance. +##### Fixed Fields for RFC6570-style Serialization -###### Encoding `multipart` Media Types - -The `form-data` disposition and its `name` parameter are mandatory for `multipart/form-data` ([RFC7578 §4.2](https://www.rfc-editor.org/rfc/rfc7578.html#section-4.2)). -Array properties are handled by applying the same `name` to multiple parts, as is recommended by [RFC7578 §4.2](https://www.rfc-editor.org/rfc/rfc7578.html#section-4.3) for supplying multiple values per form field. -See [RFC7578 §5](https://www.rfc-editor.org/rfc/rfc7578.html#section-5) for guidance regarding non-ASCII part names. - -Various other `multipart` types, most notable `multipart/mixed` ([RFC2046 §5.1.3](https://www.rfc-editor.org/rfc/rfc2046.html#section-5.1.3)) neither require nor forbid specific `Content-Disposition` values, which means care must be taken to ensure that any values used are supported by all relevant software. -It is not currently possible to correlate schema properties with unnamed, ordered parts in media types such as `multipart/mixed`, but implementations MAY choose to support such types when `Content-Disposition: form-data` is used with a `name` parameter. - -Note that there are significant restrictions on what headers can be used with `multipart` media types in general ([RFC2046 §5.1](https://www.rfc-editor.org/rfc/rfc2046.html#section-5.1)) and `multi-part/form-data` in particular ([RFC7578 §4.8](https://www.rfc-editor.org/rfc/rfc7578.html#section-4.8)). - -Note also that `Content-Transfer-Encoding` is deprecated for `multipart/form-data` ([RFC7578 §4.7](https://www.rfc-editor.org/rfc/rfc7578.html#section-4.7)) where binary data is supported, as it is in HTTP. -Using `format: byte` for a multipart field is equivalent to setting `Content-Transfer-Encoding: base64`. -If `format: byte` is used along with setting a different `Content-Transfer-Encoding` value with the `headers` field, the result is undefined. +Field Name | Type | Description +---|:---:|--- +style | `string` | Describes how a specific property value will be serialized depending on its type. See [Parameter Object](#parameterObject) for details on the [`style`](#parameterStyle) property. The behavior follows the same values as `query` parameters, including default values. This property SHALL be ignored if the request body media type is not `application/x-www-form-urlencoded` or `multipart/form-data`. If a value is explicitly defined, then the value of [`contentType`](#encodingContentType) (implicit or explicit) SHALL be ignored. +explode | `boolean` | When this is true, property values of type `array` or `object` generate separate parameters for each value of the array, or key-value-pair of the map. For other types of properties this property has no effect. When [`style`](#encodingStyle) is `form`, the default value is `true`. For all other styles, the default value is `false`. This property SHALL be ignored if the request body media type is not `application/x-www-form-urlencoded` or `multipart/form-data`. If a value is explicitly defined, then the value of [`contentType`](#encodingContentType) (implicit or explicit) SHALL be ignored. +allowReserved | `boolean` | When this is true, parameter values are serialized using reserved expansion, as defined by [RFC6570](https://datatracker.ietf.org/doc/html/rfc6570#autoid-20), which allows [RFC3986's reserved character set](https://datatracker.ietf.org/doc/html/rfc3986#autoid-13), as well as percent-encoded triples, to pass through unchanged, while still percent-encoding all other disallowed characters (including `%` outside of percent-encoded triples). Applications are still responsible for percent-encoding reserved characters that are [not allowed in the query string](https://datatracker.ietf.org/doc/html/rfc3986#autoid-24) (`[`, `]`, `#`), or have a special meaning in `application/x-www-form-urlencoded` (`-`, `&`, `+`); see Appendices [C](#usingRFC6570Implementations) and [E](#percentEncodingAndFormMediaTypes) for details. The default value is `false`. This property SHALL be ignored if the request body media type is not `application/x-www-form-urlencoded` or `multipart/form-data`. If a value is explicitly defined, then the value of [`contentType`](#encodingContentType) (implicit or explicit) SHALL be ignored. -###### Encoding the `application/x-www-form-urlencoded` Media Type +See also [Appendix C: Using RFC6570 Implementations](#usingRFC6570Implementations) for additional guidance. The role of `contentType` with `application/x-www-form-urlencoded` request bodies was not described in detail in version 3.0.3 and earlier of this specification. To match the intent of these fields and be compatible with version 3.1 of this specification, it is RECOMMENDED that whenever any of `style`, `explode`, or `allowReserved` are present with an explicit value: @@ -1815,6 +1806,21 @@ However, if all three of `style`, `explode`, and `allowReserved` fields are abse This makes the presence of at least one of `style`, `explode`, or `allowReserved` with an explicit value equivalent to using `schema` with `in: query` Parameter Objects, and their absence the equivalent of using `content`, but with the media type specified in `contentType` rather than through a Media Type Object. +###### Encoding `multipart` Media Types + +The `form-data` disposition and its `name` parameter are mandatory for `multipart/form-data` ([RFC7578 §4.2](https://www.rfc-editor.org/rfc/rfc7578.html#section-4.2)). +Array properties are handled by applying the same `name` to multiple parts, as is recommended by [RFC7578 §4.3](https://www.rfc-editor.org/rfc/rfc7578.html#section-4.3) for supplying multiple values per form field. +See [RFC7578 §5](https://www.rfc-editor.org/rfc/rfc7578.html#section-5) for guidance regarding non-ASCII part names. + +Various other `multipart` types, most notable `multipart/mixed` ([RFC2046 §5.1.3](https://www.rfc-editor.org/rfc/rfc2046.html#section-5.1.3)) neither require nor forbid specific `Content-Disposition` values, which means care must be taken to ensure that any values used are supported by all relevant software. +It is not currently possible to correlate schema properties with unnamed, ordered parts in media types such as `multipart/mixed`, but implementations MAY choose to support such types when `Content-Disposition: form-data` is used with a `name` parameter. + +Note that there are significant restrictions on what headers can be used with `multipart` media types in general ([RFC2046 §5.1](https://www.rfc-editor.org/rfc/rfc2046.html#section-5.1)) and `multi-part/form-data` in particular ([RFC7578 §4.8](https://www.rfc-editor.org/rfc/rfc7578.html#section-4.8)). + +Note also that `Content-Transfer-Encoding` is deprecated for `multipart/form-data` ([RFC7578 §4.7](https://www.rfc-editor.org/rfc/rfc7578.html#section-4.7)) where binary data is supported, as it is in HTTP. +Using `format: byte` for a multipart field is equivalent to setting `Content-Transfer-Encoding: base64`. +If `format: byte` is used along with setting a different `Content-Transfer-Encoding` value with the `headers` field, the result is undefined. + ##### Encoding Object Example `multipart/form-data` allows for binary parts: From 137dfcbab7482838f41394c5ba37dda7a68474f2 Mon Sep 17 00:00:00 2001 From: "Henry H. Andrews" Date: Tue, 11 Jun 2024 11:21:09 -0700 Subject: [PATCH 23/37] Discuss null values and contentType (3.1.1 port of 3857 4/4) --- versions/3.1.1.md | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/versions/3.1.1.md b/versions/3.1.1.md index 47757e4a9c..31d306e767 100644 --- a/versions/3.1.1.md +++ b/versions/3.1.1.md @@ -1774,15 +1774,20 @@ Field Name | Type | Description This object MAY be extended with [Specification Extensions](#specificationExtensions). -The default values for `contentType` are as follows: +The default values for `contentType` are as follows, where an _n/a_ in the `format` column means that the presence or value of `format` is irrelevant: -Property Type | Property Format | Default `contentType` +Property `type` | Property `format` | Default `contentType` ------------- | --------------- | --------------------- `string` | `binary` | `application/octet-stream` -`string`, `number`, `integer`, or `boolean` | _n/a_ | `text/plain` +`string` | _none, or any except `binary`_ | `text/plain` +`number`, `integer`, or `boolean` | _n/a_ | `text/plain` `object` | _n/a_ | `application/json` `array` | _n/a_ | according to the `type` and `format` of the `items` schema +Determining how to handle `null` values if `nullable: true` is present depends on how `null` values are being serialized. +If `null` values are entirely omitted, then the `contentType` is irrelevant. +See [Appendix B](#dataTypeConversion) for a discussion of data type conversion options. + ##### Fixed Fields for RFC6570-style Serialization Field Name | Type | Description From 9ac976ae6764a3b7fb5a8b077bb1127b80c21a67 Mon Sep 17 00:00:00 2001 From: "Henry H. Andrews" Date: Sat, 25 May 2024 15:50:29 -0700 Subject: [PATCH 24/37] Appendix for percent-encoding concerns (3.1.1 port of 3859 1/3) Percent-encoding is a minefield, although in practice it mostly works. This appendix attempts to acknowledge the concerns and then define enough terminology and link to enough other specifications that interested readers will be able to research further details. --- versions/3.1.1.md | 102 ++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 98 insertions(+), 4 deletions(-) diff --git a/versions/3.1.1.md b/versions/3.1.1.md index 31d306e767..0a4120935b 100644 --- a/versions/3.1.1.md +++ b/versions/3.1.1.md @@ -1166,6 +1166,8 @@ Describes a single operation parameter. A unique parameter is defined by a combination of a [name](#parameterName) and [location](#parameterIn). +See [Appendix E](#percentEncodingAndFormMediaTypes) for a detailed examination of percent-encoding concerns, including interactions with the `application/x-www-form-urlencoded` query string format. + ##### Parameter Locations There are four possible parameter locations specified by the `in` field: * path - Used together with [Path Templating](#pathTemplating), where the parameter value is actually part of the operation's URL. This does not include the host or base path of the API. For example, in `/items/{itemId}`, the path parameter is `itemId`. @@ -1236,7 +1238,7 @@ spaceDelimited | `array`, `object` | `query` | Space separated array values or o pipeDelimited | `array`, `object` | `query` | Pipe separated array values or object properties and values. This option replaces `collectionFormat` equal to `pipes` from OpenAPI 2.0. deepObject | `object` | `query` | Allows objects with scalar properties to be represented using form parameters. The representation of array or object properties is not defined. -The behavior of applying a style that uses a delimiter to data containing that delimiter is not defined, and is therefore NOT RECOMMENDED. To ensure interoperability, any such delimiter characters need to be escaped prior to serializing with the style, and unescaped after parsing. In the case of `spaceDelimited`, care must be taken to avoid confusing interactions with URL parameter encoding of spaces. +See [Appendix E](#percentEncodingAndFormMediaTypes) for a discussion of percent-encoding, including when delimiters need to be percent-encoded and options for handling collisions with percent-encoded data. ##### Style Examples @@ -1247,7 +1249,8 @@ Assume a parameter named `color` has one of the following values: array -> ["blue","black","brown"] object -> { "R": 100, "G": 200, "B": 150 } ``` -The following table shows examples of rendering differences for each value. +The following table shows examples of the different serializations for each value. +The examples are percent-encoded as required by RFC6570 and RFC3986; see [Appendix E](#percentEncodingAndFormMediaTypes) for a thorough discussion of percent-encoding concerns, including why unencoded `|` (`%7C`), `[` (`%5B`), and `]` (`%5D`) seem to work in some environments despite not being compliant. [`style`](#styleValues) | `explode` | `empty` | `string` | `array` | `object` ----------- | ------ | -------- | -------- | -------- | ------- @@ -1260,8 +1263,8 @@ simple | true | n/a | blue | blue,black,brown | R=100,G=200,B=150 form | false | color= | color=blue | color=blue,black,brown | color=R,100,G,200,B,150 form | true | color= | color=blue | color=blue&color=black&color=brown | R=100&G=200&B=150 spaceDelimited | false | n/a | n/a | color=blue%20black%20brown | color=R%20100%20G%20200%20B%20150 -pipeDelimited | false | n/a | n/a | color=blue\|black\|brown | color=R\|100\|G\|200\|B\|150 -deepObject | true | n/a | n/a | n/a | color[R]=100&color[G]=200&color[B]=150 +pipeDelimited | false | n/a | n/a | color=blue%7Cblack%7Cbrown | color=R%7C100%7CG%7C200%7CB%7C150 +deepObject | true | n/a | n/a | n/a | color%5BR%5D=100&color%5BG%5D=200&color%5BB%5D=150 This object MAY be extended with [Specification Extensions](#specificationExtensions). @@ -1703,6 +1706,8 @@ Here is the `id` parameter (without `address`) serialized as `application/json` id=%22f81d4fae-7dec-11d0-a765-00a0c91e6bf6%22 ``` +See [Appendix E](#percentEncodingAndFormMediaTypes) for a detailed examination of percent-encoding concerns for form media types. + ##### Special Considerations for `multipart` Content It is common to use `multipart/form-data` as a `Content-Type` when transferring request bodies to operations. In contrast to 2.0, a `schema` is REQUIRED to define the input parameters to the operation when using `multipart` content. This supports complex structures as well as supporting mechanisms for multiple file uploads. @@ -1763,6 +1768,8 @@ See [Appendix B](#dataTypeConversion) for a discussion of converting values of v Properties are correlated with `multipart` parts using the `name` parameter to `Content-Disposition: form-data`, and with `application/x-www-form-urlencoded` using the query string paramter names. In both cases, their order is implementation-defined. +See [Appendix E](#percentEncodingAndFormMediaTypes) for a detailed examination of percent-encoding concerns for form media types. + ###### Common Fixed Fields These fields MAY be used either with or without the RFC6570-style serialization fields defined in the next section below. @@ -4441,3 +4448,90 @@ Because implementations that rely on an RFC6570 implementation and those that pe For multiple values, `style: form` is always incorrect as name=value pairs in cookies are delimited by `; ` (a semicolon followed by a space character) rather than `&`. ## Appendix E: Percent-Encoding and Form Media Types + +_**NOTE:** In this section, the `application/x-www-form-urlencoded` and `multipart/form-data` media types are abbreviated as `form-urlencoded` and `form-data`, respectively, for readability._ + +Percent-encoding is used in URIs and media types that derive their syntax from URIs. +This process is concerned with three sets of characters, the names of which vary among specifications but are defined as follows for the purposes of this section: + +* _unreserved_ characters do not need to be percent-encoded; while it is safe to percent-encode them, doing so produces a URI that is [not normalized](https://datatracker.ietf.org/doc/html/rfc3986#section-6.2.2.2) +* _reserved_ characters either have special behavior in the URI syntax (such as delimiting components) or are reserved for other specifications that need to define special behavior (e.g. `form-urlencoded` defines special behavior for `=`, `&`, and `+`) +* _unsafe_ characters are known to cause problems when parsing URIs in certain environments + +Unless otherwise specified, this section uses RFC3986's definition of [reserved](https://datatracker.ietf.org/doc/html/rfc3986#section-2.2) and [unreserved](https://datatracker.ietf.org/doc/html/rfc3986#section-2.3), and defines the unsafe set as all characters not included in either of those sets. + +### Percent-Encoding and `form-urlencoded` + +Each URI component (such as the query string) considers some of the reserved characters to be unsafe, either because they serve as delimiters between the components (e.g. `#`), or (in the case of `[` and `]`) were historically considered globally unsafe but were later given reserved status for limited purposes. + +Reserved characters with no special meaning defined within a component can be left un-percent encoded. +However, other specifications can define special meanings, requiring percent-encoding for those characters outside of the additional special meanings. + +The `form-urlencoded` media type defines special meanings for `=` and `&` as delimiters, and `+` as the replacement for the space character (instead of its percent-encoded form of `%20`). +This means that while these three characters are reserved-but-allowed in query strings by RFC3986, they must be percent-encoded in `form-urlencoded` query strings except when used for their `form-urlencoded` purposes; see [Appendix C](#usingRFC6570Implementations) for an example of handling `+` in form values. + +### Percent-Encoding and `form-data` + +[RFC7578 §2](https://datatracker.ietf.org/doc/html/rfc7578#section-2) suggests RFC3986-based percent-encoding as a mechanism to keep text-based per-part header data such as file names within the ASCII character set. +This suggestion was not part of older (pre-2015) specifications for `form-data`, so care must be taken to ensure interoperability. + +The `form-data` media type allows arbitrary text or binary data in its parts, so percent-encoding is not needed and is likely to cause interoperability problems unless the `Content-Type` of the part is defined to require it. + +### Generating and Validating URIs and `form-urlencoded` Strings + +URI percent encoding and the `form-urlencoded` media type have complex specification histories spanning multiple revisions and, in some cases, conflicting claims of ownership by different standards bodies. +Unfortunately, these specifications each define slightly different percent-encoding rules, which need to be taken into account if the URIs or `form-urlencoded` message bodies will be subject to strict validation. +(Note that many URI parsers do not perform validation by default.) + +This specification normatively cites the following relevant standards: + +Specification | Date | OAS Usage | Percent-Encoding | Notes +------------- | ---- | --------- | ----- | ----- +[RFC3986 URI Generic Syntax](https://datatracker.ietf.org/doc/html/rfc3986) | 01/2005 | URI/URL syntax | RFC3986 | obsoletes RFC1738, RFC2396 +[RFC6570 URI Template](https://datatracker.ietf.org/doc/html/rfc6570) | 03/2012 | style-based serialization | RFC3986 | does not use `+` for form‑urlencoded +[RFC1866 §8.2.1 form‑urlencoded](https://datatracker.ietf.org/doc/html/rfc1866#section-8.2.1) | 11/1995 | content-based serialization | RFC1738 | obsoleted by [HTML 4.01 §17.13.4.1](https://www.w3.org/TR/html401/interact/forms.html#h-17.13.4.1), [WHATWG URL §5](https://url.spec.whatwg.org/#urlencoded-serializing) + +Style-based serialization is used in the [Parameter Object](#parameterObject) when `schema` is present, and in the [Encoding Object](#encodingObject) when at least one of `style`, `explode`, or `allowReserved` is present. +See [Appendix C](#usingRFC6570Implementations) for more details of RFC6570's two different approaches to percent-encoding, including an example involving `+`. + +Content-based serialization is defined by the [Media Type Object](#mediaTypeObject), and used with the [Parameter Object](#parameterObject) when the `content` field is present, and with the [Encoding Object](#encodingObject) based on the `contentType` field when the style fields listed in the previous section are absent. +Each part is encoded based on the media type (e.g. `text/plain` or `application/json`), and must then be percent-encoded for use in a `form-urlencoded` string. + +Note that content-based serialization for `form-data` does not expect or require percent-encoding in the data, only in per-part header values. + +#### Interoperability with Historical Specifications + +In most cases, generating query strings in strict compliance with RFC3986 is sufficient to pass validation (including JSON Schema's `format: uri` and `format: uri-reference`), but some `form-urlencoded` implementations still expect the slightly more restrictive RFC1738 rules to be used. + +Since all RFC1738-compliant URIs are compliant with RFC3986, applications needing to ensure historical interoperability SHOULD use RFC1738's rules. + +#### Interoperability with Web Browser Environments + +WHATWG is a [web browser-oriented](https://whatwg.org/faq#what-is-the-whatwg-working-on) standards group that has defined a "URL Living Standard" for parsing and serializing URLs in a browser context, including parsing and serializing `form-urlencoded` data. +WHATWG's percent-encoding rules for query strings are different depending on whether the query string is [being treated as `form-urlencoded`](https://url.spec.whatwg.org/#application-x-www-form-urlencoded-percent-encode-set) (where it requires more percent-encoding than RFC1738) or [as part of the generic syntax](https://url.spec.whatwg.org/#query-percent-encode-set), where it allows characters that RFC3986 forbids. + +Implementations needing maximum compatibility with web browsers SHOULD use WHATWG's `form-urlencoded` percent-encoding rules. +However, they SHOULD NOT rely on WHATWG's less stringent generic query string rules, as the resulting URLs would fail RFC3986 validation, including JSON Schema's `format: uri` and `format: uri-reference`. + +### Decoding URIs and `form-urlencoded` Strings + +The percent-decoding algorithm does not care which characters were or were not percent-decoded, which means that URIs percent-encoded according to any specification will be decoded correctly. + +Similarly, all `form-urlencoded` decoding algorithms simply add `+`-for-space handling to the percent-decoding algorithm, and will work regardless of the encoding specification used. + +However, care must be taken to use `form-urlencoded` decoding if `+` represents a space, and to use regular percent-decoding if `+` represents itself as a literal value. + +### Percent-Encoding and Illegal or Reserved Delimiters + +The `[` and `]`, `|`, and space characters, which are used as delimiters for the `deepObject`, `pipeDelimited`, and `spaceDelimited` styles, respectively, all MUST be percent-encoded to comply with RFC3986. +This requires users to pre-encode the character(s) in some other way in parameter names and values to distinguish them from the delimiter usage when using one of these styles. + +The space character is always illegal and encoded in some way by all implementations of all versions of the relevant standards. +While one could use the `form-urlencoded` convention of `+` to distinguish spaces in parameter names and values from `spaceDelimited` delimiters encoded as `%20`, the specifications define the decoding as a single pass, making it impossible to distinguish the different usages in the decoded result. + +Some environments use `[`, `]`, and possibly `|` unencoded in query strings without apparent difficulties, and WHATWG's generic query string rules do not require percent-encoding them. +Code that relies on leaving these delimiters unencoded, while using regular percent-encoding for them within names and values, is not guaranteed to be interoperable across all implementations. + +For maximum interoperability, it is RECOMMENDED to either define and document an additional escape convention while percent-encoding the delimiters for these styles, or to avoid these styles entirely. +The exact method of additional encoding/escaping is left to the API designer, and is expected to be performed before serialization and encoding described in this specification, and reversed after this specification's encoding and serialization steps are reversed. +This keeps it outside of the processes governed by this specification. From 2e79a5470b5541bea1436a03bcef89fbe41eddd1 Mon Sep 17 00:00:00 2001 From: "Henry H. Andrews" Date: Sat, 8 Jun 2024 15:43:46 -0700 Subject: [PATCH 25/37] Further clarify style+explode examples (3.1.1 port of 3859 2/3) This aligns all examples with RFC6570 operator prefixing behavior, which was previously only shown for `matrix` and `label`. The non-RFC6570 styles (`spaceDelimited`, `pipeDelimited`, and `deepObject`) are treated as analogues of `form` and therefore prefixed with a `?`. The lack of suitablity of this for cookie parameters has been addressed with an appendix in another change, and the appendix has been stubbed out here to ensure that the link is valid. Switch the "empty" column heading to "undefined" to align with RFC6570 and make clear that it is not about `allowEmptyValue` --- versions/3.1.1.md | 40 +++++++++++++++++++++++++--------------- 1 file changed, 25 insertions(+), 15 deletions(-) diff --git a/versions/3.1.1.md b/versions/3.1.1.md index 0a4120935b..af927c4155 100644 --- a/versions/3.1.1.md +++ b/versions/3.1.1.md @@ -1181,6 +1181,8 @@ The rules for serialization of the parameter are specified in one of two ways. Parameter Objects MUST include either a `content` field or a `schema` field, but not both. See [Appendix B](#dataTypeConversion) for a discussion of converting values of various types to string representations. +This object MAY be extended with [Specification Extensions](#specificationExtensions). + ###### Common Fixed Fields These fields MAY be used with either `content` or `schema`. @@ -1192,7 +1194,7 @@ Field Name | Type | Description description | `string` | A brief description of the parameter. This could contain examples of use. [CommonMark syntax](https://spec.commonmark.org/) MAY be used for rich text representation. required | `boolean` | Determines whether this parameter is mandatory. If the [parameter location](#parameterIn) is `"path"`, this property is **REQUIRED** and its value MUST be `true`. Otherwise, the property MAY be included and its default value is `false`. deprecated | `boolean` | Specifies that a parameter is deprecated and SHOULD be transitioned out of usage. Default value is `false`. - allowEmptyValue | `boolean` | If `true`, clients MAY pass a zero-length string value in place of parameters that would otherwise be omitted entirely, which the server SHOULD interpret as the parameter being unused. Default value is `false`. If [`style`](#parameterStyle) is used, and if behavior is `n/a` (cannot be serialized), the value of `allowEmptyValue` SHALL be ignored. Interactions between this field and the parameter's [Schema Object](#schemaObject) are implementation-defined. This field is valid only for `query` parameters. Use of this property is NOT RECOMMENDED, and it is likely to be removed in a later revision. + allowEmptyValue | `boolean` | If `true`, clients MAY pass a zero-length string value in place of parameters that would otherwise be omitted entirely, which the server SHOULD interpret as the parameter being unused. Default value is `false`. If [`style`](#parameterStyle) is used, and if [behavior is _n/a_ (cannot be serialized)](#style-examples), the value of `allowEmptyValue` SHALL be ignored. Interactions between this field and the parameter's [Schema Object](#schemaObject) are implementation-defined. This field is valid only for `query` parameters. Use of this property is NOT RECOMMENDED, and it is likely to be removed in a later revision. Note that while `"Cookie"` as a `name` is not forbidden with `in: header`, the effect of defining a cookie parameter that way is undefined; use `in: cookie` instead. @@ -1207,7 +1209,7 @@ Serializing with `schema` is NOT RECOMMENDED for `in: cookie` parameters, `in: h Field Name | Type | Description ---|:---:|--- style | `string` | Describes how the parameter value will be serialized depending on the type of the parameter value. Default values (based on value of `in`): for `query` - `form`; for `path` - `simple`; for `header` - `simple`; for `cookie` - `form`. -explode | `boolean` | When this is true, parameter values of type `array` or `object` generate separate parameters for each value of the array or key-value pair of the map. For other types of parameters this property has no effect. When [`style`](#parameterStyle) is `form`, the default value is `true`. For all other styles, the default value is `false`. +explode | `boolean` | When this is true, parameter values of type `array` or `object` generate separate parameters for each value of the array or key-value pair of the map. For other types of parameters this property has no effect. When [`style`](#parameterStyle) is `form`, the default value is `true`. For all other styles, the default value is `false`. Note that despite `false` being the default for `deepObject`, the combination of `false` with `deepObject` is undefined. allowReserved | `boolean` | When this is true, parameter values are serialized using reserved expansion, as defined by [RFC6570](https://datatracker.ietf.org/doc/html/rfc6570#autoid-20), which allows [RFC3986's reserved character set](https://datatracker.ietf.org/doc/html/rfc3986#autoid-13), as well as percent-encoded triples, to pass through unchanged, while still percent-encoding all other disallowed characters (including `%` outside of percent-encoded triples). Applications are still responsible for percent-encoding reserved characters that are [not allowed in the query string](https://datatracker.ietf.org/doc/html/rfc3986#autoid-24) (`[`, `]`, `#`), or have a special meaning in `application/x-www-form-urlencoded` (`-`, `&`, `+`); see Appendices [C](#usingRFC6570Implementations) and [E](#percentEncodingAndFormMediaTypes) for details. This property only applies to parameters with an `in` value of `query`. The default value is `false`. schema | [Schema Object](#schemaObject) | The schema defining the type used for the parameter. example | Any | Example of the parameter's potential value; see [Working With Examples](#working-with-examples). @@ -1249,8 +1251,15 @@ Assume a parameter named `color` has one of the following values: array -> ["blue","black","brown"] object -> { "R": 100, "G": 200, "B": 150 } ``` -The following table shows examples of the different serializations for each value. -The examples are percent-encoded as required by RFC6570 and RFC3986; see [Appendix E](#percentEncodingAndFormMediaTypes) for a thorough discussion of percent-encoding concerns, including why unencoded `|` (`%7C`), `[` (`%5B`), and `]` (`%5D`) seem to work in some environments despite not being compliant. + +The following table shows examples, as would be shown with the `example` or `examples` keywords, of the different serializations for each value. + +* The value _empty_ denotes the empty string, and is unrelated to the `allowEmptyValue` field +* The behavior of combinations marked _n/a_ is undefined +* The `undefined` replaces the `empty` column in previous versions of this specification in order to better align with [RFC6570 §2.3](https://www.rfc-editor.org/rfc/rfc6570.html#section-2.3) terminology, which describes certain values including but not limited to `null` as "undefined" values with special handling; notably, the empty string is _not_ undefined +* For `form` and the non-RFC6570 query string styles `spaceDelimited`, `pipeDelimited`, and `deepObject`, each example is shown prefixed with `?` as if it were the only query parameter; see [Appendix C](#usingRFC6570Implementations) for more information on constructing query strings from multiple parameters, and [Appendix D](#serializingHeadersAndCookies) for warnings regarding `form` and cookie parameters +* Note that the `?` prefix is not appropriate for serializing `application/x-www-form-urlencoded` HTTP message bodies, and MUST be stripped or (if constructing the string manually) not added when used in that context; see the [Encoding Object](#encodingObject) for more information +* The examples are percent-encoded as required by RFC6570 and RFC3986; see [Appendix E](#percentEncodingAndFormMediaTypes) for a thorough discussion of percent-encoding concerns, including why unencoded `|` (`%7C`), `[` (`%5B`), and `]` (`%5D`) seem to work in some environments despite not being compliant. [`style`](#styleValues) | `explode` | `empty` | `string` | `array` | `object` ----------- | ------ | -------- | -------- | -------- | ------- @@ -1258,15 +1267,16 @@ matrix | false | ;color | ;color=blue | ;color=blue,black,brown | ;color=R,100,G matrix | true | ;color | ;color=blue | ;color=blue;color=black;color=brown | ;R=100;G=200;B=150 label | false | . | .blue | .blue,black,brown | .R,100,G,200,B,150 label | true | . | .blue | .blue.black.brown | .R=100.G=200.B=150 -simple | false | n/a | blue | blue,black,brown | R,100,G,200,B,150 -simple | true | n/a | blue | blue,black,brown | R=100,G=200,B=150 -form | false | color= | color=blue | color=blue,black,brown | color=R,100,G,200,B,150 -form | true | color= | color=blue | color=blue&color=black&color=brown | R=100&G=200&B=150 -spaceDelimited | false | n/a | n/a | color=blue%20black%20brown | color=R%20100%20G%20200%20B%20150 -pipeDelimited | false | n/a | n/a | color=blue%7Cblack%7Cbrown | color=R%7C100%7CG%7C200%7CB%7C150 -deepObject | true | n/a | n/a | n/a | color%5BR%5D=100&color%5BG%5D=200&color%5BB%5D=150 - -This object MAY be extended with [Specification Extensions](#specificationExtensions). +simple | false | _empty_ | blue | blue,black,brown | R,100,G,200,B,150 +simple | true | _empty_ | blue | blue,black,brown | R=100,G=200,B=150 +form | false | ?color= | ?color=blue | ?color=blue,black,brown | ?color=R,100,G,200,B,150 +form | true | ?color= | ?color=blue | ?color=blue&color=black&color=brown | ?R=100&G=200&B=150 +spaceDelimited | false | _n/a_ | _n/a_ | ?color=blue%20black%20brown | ?color=R%20100%20G%20200%20B%20150 +spaceDelimited | true | _n/a_ | _n/a_ | _n/a_ | _n/a_ +pipeDelimited | false | _n/a_ | _n/a_ | ?color=blue%7Cblack%7Cbrown | ?color=R%7C100%7CG%7C200%7CB%7C150 +pipeDelimited | true | _n/a_ | _n/a_ | _n/a_ | _n/a_ +deepObject | false | _n/a_ | _n/a_ | _n/a_ | _n/a_ +deepObject | true | _n/a_ | _n/a_ | _n/a_ | ?color%5BR%5D=100&color%5BG%5D=200&color%5BB%5D=150 ##### Parameter Object Examples @@ -1799,8 +1809,8 @@ See [Appendix B](#dataTypeConversion) for a discussion of data type conversion o Field Name | Type | Description ---|:---:|--- -style | `string` | Describes how a specific property value will be serialized depending on its type. See [Parameter Object](#parameterObject) for details on the [`style`](#parameterStyle) property. The behavior follows the same values as `query` parameters, including default values. This property SHALL be ignored if the request body media type is not `application/x-www-form-urlencoded` or `multipart/form-data`. If a value is explicitly defined, then the value of [`contentType`](#encodingContentType) (implicit or explicit) SHALL be ignored. -explode | `boolean` | When this is true, property values of type `array` or `object` generate separate parameters for each value of the array, or key-value-pair of the map. For other types of properties this property has no effect. When [`style`](#encodingStyle) is `form`, the default value is `true`. For all other styles, the default value is `false`. This property SHALL be ignored if the request body media type is not `application/x-www-form-urlencoded` or `multipart/form-data`. If a value is explicitly defined, then the value of [`contentType`](#encodingContentType) (implicit or explicit) SHALL be ignored. +style | `string` | Describes how a specific property value will be serialized depending on its type. See [Parameter Object](#parameterObject) for details on the [`style`](#parameterStyle) property. The behavior follows the same values as `query` parameters, including default values. Note that the initial `?` using in query strings is not used in `applcation/x-www-form-urlencoded` message bodies, and MUST be removed (if using an RFC6570 implementation) or simply not added (if constructing the string manually). This property SHALL be ignored if the request body media type is not `application/x-www-form-urlencoded` or `multipart/form-data`. If a value is explicitly defined, then the value of [`contentType`](#encodingContentType) (implicit or explicit) SHALL be ignored. +explode | `boolean` | When this is true, property values of type `array` or `object` generate separate parameters for each value of the array, or key-value-pair of the map. For other types of properties this property has no effect. When [`style`](#encodingStyle) is `form`, the default value is `true`. For all other styles, the default value is `false`. Note that despite `false` being the default for `deepObject`, the combination of `false` with `deepObject` is undefined. This property SHALL be ignored if the request body media type is not `application/x-www-form-urlencoded` or `multipart/form-data`. If a value is explicitly defined, then the value of [`contentType`](#encodingContentType) (implicit or explicit) SHALL be ignored. allowReserved | `boolean` | When this is true, parameter values are serialized using reserved expansion, as defined by [RFC6570](https://datatracker.ietf.org/doc/html/rfc6570#autoid-20), which allows [RFC3986's reserved character set](https://datatracker.ietf.org/doc/html/rfc3986#autoid-13), as well as percent-encoded triples, to pass through unchanged, while still percent-encoding all other disallowed characters (including `%` outside of percent-encoded triples). Applications are still responsible for percent-encoding reserved characters that are [not allowed in the query string](https://datatracker.ietf.org/doc/html/rfc3986#autoid-24) (`[`, `]`, `#`), or have a special meaning in `application/x-www-form-urlencoded` (`-`, `&`, `+`); see Appendices [C](#usingRFC6570Implementations) and [E](#percentEncodingAndFormMediaTypes) for details. The default value is `false`. This property SHALL be ignored if the request body media type is not `application/x-www-form-urlencoded` or `multipart/form-data`. If a value is explicitly defined, then the value of [`contentType`](#encodingContentType) (implicit or explicit) SHALL be ignored. See also [Appendix C: Using RFC6570 Implementations](#usingRFC6570Implementations) for additional guidance. From fe71ea3aee5be1c5d78341fc83b7ed308f3170b2 Mon Sep 17 00:00:00 2001 From: "Henry H. Andrews" Date: Mon, 10 Jun 2024 15:40:42 -0700 Subject: [PATCH 26/37] Update Header for changes to copied fields (3.1.1 port of 3859 3/3, 3911 2/2) --- versions/3.1.1.md | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/versions/3.1.1.md b/versions/3.1.1.md index af927c4155..35faeb14c4 100644 --- a/versions/3.1.1.md +++ b/versions/3.1.1.md @@ -2579,13 +2579,16 @@ When `example` or `examples` are provided in conjunction with the `schema` objec Serializing with `schema` is NOT RECOMMENDED for headers with parameters (name=value pairs following a `;`) in their values, or where values might have non-URL-safe characters; see [Appendix D](#serializingHeadersAndCookies) for details. +When `example` or `examples` are provided in conjunction with the `schema` object, the example SHOULD match the specified schema and follow the prescribed serialization strategy for the header. +The `example` and `examples` fields are mutually exclusive, and if either is present it SHALL _override_ any `example` in the schema. + Field Name | Type | Description ---|:---:|--- style | `string` | Describes how the header value will be serialized. The default (and only legal value for headers) is `simple`. explode | `boolean` | When this is true, header values of type `array` or `object` generate a single header whose value is a comma-separated list of the array items or key-value pairs of the map, see [Style Examples](#style-examples). For other data types this property has no effect. The default value is `false`. schema | [Schema Object](#schemaObject) \| [Reference Object](#referenceObject) | The schema defining the type used for the header. -example | Any | Example of the header's potential value. The example SHOULD match the specified schema and encoding properties if present. The `example` field is mutually exclusive of the `examples` field. Furthermore, if referencing a `schema` that contains an example, the `example` value SHALL _override_ the example provided by the schema. To represent examples of media types that cannot naturally be represented in JSON or YAML, a string value can contain the example with escaping where necessary. -examples | Map[ `string`, [Example Object](#exampleObject) \| [Reference Object](#referenceObject)] | Examples of the header's potential value. Each example SHOULD contain a value in the correct format as specified in the header encoding. The `examples` field is mutually exclusive of the `example` field. Furthermore, if referencing a `schema` that contains an example, the `examples` value SHALL _override_ the example provided by the schema. +example | Any | Example of the header's potential value; see [Working With Examples](#working-with-examples). +examples | Map[ `string`, [Example Object](#exampleObject) \| [Reference Object](#referenceObject)] | Examples of the header's potential value; see [Working With Examples](#working-with-examples). See also [Appendix C: Using RFC6570 Implementations](#usingRFC6570Implementations) for additional guidance. From 6b635803342f70b7b2b057d6374b85db8dac1501 Mon Sep 17 00:00:00 2001 From: "Henry H. Andrews" Date: Sat, 15 Jun 2024 09:44:24 -0700 Subject: [PATCH 27/37] Include Header Object in data serialization list (3.1.1 port of 3917) The PR adding Appendix B pre-dated giving the Header Object its own field tables. This adds "Header Object" to the list of relevant Objects along with the Paramter Object and the Encoding Object. --- versions/3.1.1.md | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/versions/3.1.1.md b/versions/3.1.1.md index 35faeb14c4..b695bdbcde 100644 --- a/versions/3.1.1.md +++ b/versions/3.1.1.md @@ -4179,7 +4179,7 @@ Serializing typed data to plain text, which can occur in `text/plain` message bo Schema Objects validate data based on the [JSON Schema data model](https://datatracker.ietf.org/doc/html/draft-wright-json-schema-00#section-4.2), which only recognizes four primitive data types: strings (which are [only broadly interoperable as UTF-8](https://datatracker.ietf.org/doc/html/rfc7159#section-8.1)), numbers, booleans, and `null`. Notably, integers are not a distinct type from other numbers, with `type: integer` being a convenience defined mathematically, rather than based on the presence or absence of a decimal point in any string representation. -The [Parameter Object](#parameterObject) and [Encoding Object](#encodingObject) offer features to control how to arrange values from array or object types. +The [Parameter Object](#parameterObject), [Header Object](#headerObject) and [Encoding Object](#encodingObject) offer features to control how to arrange values from array or object types. They can also be used to control how strings are further encoded to avoid reserved or illegal characters. However, there is no general-purpose specification for converting schema-validated non-UTF-8 primitive data types (or entire arrays or objects) to strings. From 4c59363629d5c460f35fa66e828a0b6a482616ad Mon Sep 17 00:00:00 2001 From: "Henry H. Andrews" Date: Sun, 9 Jun 2024 10:55:39 -0700 Subject: [PATCH 28/37] Fix XML namespace syntax (3.1.1 port of 3905) The XML Object's namespace field was changed from "URL" to "absolute URI" because relative references in a namespace are deprecated by XML, and the base URI to use for resolving them in the context of an OpenAPI Description is unclear. However, XML namespaces can include fragments, and the correct term is "non-relative URI" rather than "absolute URI" which forbids fragments. This change includes additional guidance on how XML usage and the requirements of this specification do not quite align. --- versions/3.1.1.md | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/versions/3.1.1.md b/versions/3.1.1.md index b695bdbcde..e38a190cb2 100644 --- a/versions/3.1.1.md +++ b/versions/3.1.1.md @@ -3405,13 +3405,19 @@ See examples for expected behavior. Field Name | Type | Description ---|:---:|--- name | `string` | Replaces the name of the element/attribute used for the described schema property. When defined within `items`, it will affect the name of the individual XML elements within the list. When defined alongside `type` being `array` (outside the `items`), it will affect the wrapping element and only if `wrapped` is `true`. If `wrapped` is `false`, it will be ignored. -namespace | `string` | The URI of the namespace definition. This MUST be in the form of an absolute URI. +namespace | `string` | The URI of the namespace definition. Value MUST be in the form of a non-relative URI. prefix | `string` | The prefix to be used for the [name](#xmlName). attribute | `boolean` | Declares whether the property definition translates to an attribute instead of an element. Default value is `false`. wrapped | `boolean` | MAY be used only for an array definition. Signifies whether the array is wrapped (for example, ``) or unwrapped (``). Default value is `false`. The definition takes effect only when defined alongside `type` being `array` (outside the `items`). This object MAY be extended with [Specification Extensions](#specificationExtensions). +The `namespace` keyword is intended to match the syntax of [XML namespaces](https://www.w3.org/TR/xml-names11/), although there are a few caveats: + +* Version 3.0.3 and earlier of this specification erroneously used the term "absolute URI" instead of "non-relative URI", so authors using namespaces that include a fragment should check tooling support carefully. +* XML allows but discourages relative URI-references, while this specification outright forbids them. +* XML 1.1 allows IRIs ([RFC3987](https://datatracker.ietf.org/doc/html/rfc3987)) as namespaces, and specifies that namespaces are compared without any encoding or decoding, which means that IRIs encoded to meet this specification's URI syntax requirement cannot be compared to IRIs as-is. + ##### XML Object Examples Each of the following examples represent the value of the `properties` keyword in a [Schema Object](#schemaObject) that is omitted for brevity. From 56042d7df424778e7b4f44adccb8e821067b96a7 Mon Sep 17 00:00:00 2001 From: "Henry H. Andrews" Date: Thu, 13 Jun 2024 12:22:08 -0700 Subject: [PATCH 29/37] Clarify discriminator non-impact on validation (3.1.1 port of 3907) Be very explicit that discriminator MUST NOT change the validation outcome, and explain the implication for the "allOf" use case. --- versions/3.1.1.md | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/versions/3.1.1.md b/versions/3.1.1.md index e38a190cb2..f1c7dbfc06 100644 --- a/versions/3.1.1.md +++ b/versions/3.1.1.md @@ -3249,6 +3249,8 @@ When request bodies or response payloads may be one of a number of different sch This hint can be used to aid in serialization, deserialization, and validation. The Discriminator Object does this by implicitly or explicitly associating the possible values of a named property with alternative schemas. +Note that `discriminator` MUST NOT change the validation outcome of the schema. + ##### Fixed Fields Field Name | Type | Description ---|:---:|--- @@ -3259,9 +3261,14 @@ This object MAY be extended with [Specification Extensions](#specificationExtens ##### Conditions for Using the Discriminator Object The Discriminator Object is legal only when using one of the composite keywords `oneOf`, `anyOf`, `allOf`. + In both the `oneOf` and `anyOf` use cases, where those keywords are adjacent to `discriminator`, all possible schemas MUST be listed explicitly. + To avoid redundancy, the discriminator MAY be added to a parent schema definition, and all schemas building on the parent schema via an `allOf` construct may be used as an alternate schema. +The `allOf` form of `discriminator` is _only_ useful for non-validation use cases; validation with the parent schema with this form of `discriminator` _does not_ perform a search for child schemas or use them in validation in any way. +This is because `discriminator` cannot change the validation outcome, and no standard JSON Schema keyword connects the parent schema to the child schemas. + The behavior of any configuration of `oneOf`, `anyOf`, `allOf` and `discriminator` that is not described above is undefined. ##### Options for Mapping Values to Schemas From 0332c770948714028adafa03d53c55b20781b1a5 Mon Sep 17 00:00:00 2001 From: "Henry H. Andrews" Date: Mon, 17 Jun 2024 11:36:56 -0700 Subject: [PATCH 30/37] Consisent x- Param/Encoding/Header wording (3.1.1 port of 3919) It was a bit challenging to figure out where to put the wording about allowing extension parameters when there are multiple fixed fields tables, each in their own subsection. For the Parameter Object (the only one with multiple tables in past releases), it had been after the last table, but that got further and further away from what felt like the main part of the Object description. I thought I had put it consistently after the initial "Common Fixed Fields" table, but I put it even before that in one place (which we don't do anywhere), and I forgot to include it in the Header Object at all. This change puts it after the Common Fixed Fields table for all three, which means that for all Objects it is immediately after the first Fixed Fields table. --- versions/3.1.1.md | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/versions/3.1.1.md b/versions/3.1.1.md index f1c7dbfc06..06a54589ac 100644 --- a/versions/3.1.1.md +++ b/versions/3.1.1.md @@ -1181,8 +1181,6 @@ The rules for serialization of the parameter are specified in one of two ways. Parameter Objects MUST include either a `content` field or a `schema` field, but not both. See [Appendix B](#dataTypeConversion) for a discussion of converting values of various types to string representations. -This object MAY be extended with [Specification Extensions](#specificationExtensions). - ###### Common Fixed Fields These fields MAY be used with either `content` or `schema`. @@ -1196,6 +1194,8 @@ Field Name | Type | Description deprecated | `boolean` | Specifies that a parameter is deprecated and SHOULD be transitioned out of usage. Default value is `false`. allowEmptyValue | `boolean` | If `true`, clients MAY pass a zero-length string value in place of parameters that would otherwise be omitted entirely, which the server SHOULD interpret as the parameter being unused. Default value is `false`. If [`style`](#parameterStyle) is used, and if [behavior is _n/a_ (cannot be serialized)](#style-examples), the value of `allowEmptyValue` SHALL be ignored. Interactions between this field and the parameter's [Schema Object](#schemaObject) are implementation-defined. This field is valid only for `query` parameters. Use of this property is NOT RECOMMENDED, and it is likely to be removed in a later revision. +This object MAY be extended with [Specification Extensions](#specificationExtensions). + Note that while `"Cookie"` as a `name` is not forbidden with `in: header`, the effect of defining a cookie parameter that way is undefined; use `in: cookie` instead. ###### Fixed Fields for use with `schema` @@ -2572,6 +2572,8 @@ Field Name | Type | Description required | `boolean` | Determines whether this header is mandatory. The default value is `false`. deprecated | `boolean` | Specifies that the header is deprecated and SHOULD be transitioned out of usage. Default value is `false`. +This object MAY be extended with [Specification Extensions](#specificationExtensions). + ##### Fixed Fields for use with `schema` For simpler scenarios, a [`schema`](#headerSchema) and [`style`](#headerStyle) can describe the structure and syntax of the header. From 9739dfe5afa8cb6fce5f64bbde04eb5f300658bc Mon Sep 17 00:00:00 2001 From: "Henry H. Andrews" Date: Sat, 15 Jun 2024 16:51:23 -0700 Subject: [PATCH 31/37] Minor editiorial and link target fixes (3.1.1 port of 3920) * Fix a copy-paste error that broke a link in an appendix * Fix a sentence that just kind of... wandered off * Prevent line breaks after the `?` in the form examples --- versions/3.1.1.md | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) diff --git a/versions/3.1.1.md b/versions/3.1.1.md index 06a54589ac..aab4ae1a2d 100644 --- a/versions/3.1.1.md +++ b/versions/3.1.1.md @@ -1269,14 +1269,14 @@ label | false | . | .blue | .blue,black,brown | .R,100,G,200,B,150 label | true | . | .blue | .blue.black.brown | .R=100.G=200.B=150 simple | false | _empty_ | blue | blue,black,brown | R,100,G,200,B,150 simple | true | _empty_ | blue | blue,black,brown | R=100,G=200,B=150 -form | false | ?color= | ?color=blue | ?color=blue,black,brown | ?color=R,100,G,200,B,150 -form | true | ?color= | ?color=blue | ?color=blue&color=black&color=brown | ?R=100&G=200&B=150 -spaceDelimited | false | _n/a_ | _n/a_ | ?color=blue%20black%20brown | ?color=R%20100%20G%20200%20B%20150 +form | false | ?color= | ?color=blue | ?color=blue,black,brown | ?color=R,100,G,200,B,150 +form | true | ?color= | ?color=blue | ?color=blue&color=black&color=brown | ?R=100&G=200&B=150 +spaceDelimited | false | _n/a_ | _n/a_ | ?color=blue%20black%20brown | ?color=R%20100%20G%20200%20B%20150 spaceDelimited | true | _n/a_ | _n/a_ | _n/a_ | _n/a_ -pipeDelimited | false | _n/a_ | _n/a_ | ?color=blue%7Cblack%7Cbrown | ?color=R%7C100%7CG%7C200%7CB%7C150 +pipeDelimited | false | _n/a_ | _n/a_ | ?color=blue%7Cblack%7Cbrown | ?color=R%7C100%7CG%7C200%7CB%7C150 pipeDelimited | true | _n/a_ | _n/a_ | _n/a_ | _n/a_ deepObject | false | _n/a_ | _n/a_ | _n/a_ | _n/a_ -deepObject | true | _n/a_ | _n/a_ | _n/a_ | ?color%5BR%5D=100&color%5BG%5D=200&color%5BB%5D=150 +deepObject | true | _n/a_ | _n/a_ | _n/a_ | ?color%5BR%5D=100&color%5BG%5D=200&color%5BB%5D=150 ##### Parameter Object Examples @@ -4119,7 +4119,7 @@ The extensions properties are implemented as patterned fields that are always pr Field Pattern | Type | Description ---|:---:|--- -^x- | Any | Allows extensions to the OpenAPI Schema. The field name MUST begin with `x-`, for example, `x-internal-id`. Field names beginning `x-oai-` and `x-oas-` are reserved for uses defined by the [OpenAPI Initiative](https://www.openapis.org/). The value can be any valid JSON format value (`null`, a primitive, an array or an object.) +^x- | Any | Allows extensions to the OpenAPI Schema. The field name MUST begin with `x-`, for example, `x-internal-id`. Field names beginning `x-oai-` and `x-oas-` are reserved for uses defined by the [OpenAPI Initiative](https://www.openapis.org/). The value can be any valid JSON value (`null`, a primitive, an array or an object.) The OpenAPI Initiative maintains several [extension registries](https://spec.openapis.org/registry/index.html), including registries for [individual extension keywords](https://spec.openapis.org/registry/extension/) and [extension keyword namespaces](https://spec.openapis.org/registry/namespace/). @@ -4354,7 +4354,7 @@ parameters: We can't combine the `?` and `+` RFC6570 prefixes, and there's no way with RFC6570 to replace the `,` separator with a space character. So we need to restructure the data to fit a manually constructed URI Template that passes all of the pieces through the right sort of expansion. -Here is one such template, using a made-up convention of `words.0` for the first entry in the words value, `words.1` for the second. +Here is one such template, using a made-up convention of `words.0` for the first entry in the words value, `words.1` for the second, and `words.2` for the third: ```urlencoded ?a={+a}&b={+b}&c={+c}&words={words.0} {words.1} {words.2} @@ -4367,7 +4367,7 @@ We'll also need to pre-process the values for `formulas` because while `/` and m Setting `allowReserved: true` does _not_ make reserved characters that are not allowed in URIs allowed, it just allows them to be _passed through expansion unchanged._ Therefore, any tooling still needs to percent-encode those characters because reserved expansion will not do it, but it _will_ leave the percent-encoded triples unchanged. -See also [Appendix E](#to indicate name hierarchy in substructures) for further guidance on percent-encoding and form media types, including guidance on handling the delimiter characters for `spaceDelimited`, `pipeDelimited`, and `deepObject` in parameter names and values. +See also [Appendix E](#percentEncodingAndFormMediaTypes) for further guidance on percent-encoding and form media types, including guidance on handling the delimiter characters for `spaceDelimited`, `pipeDelimited`, and `deepObject` in parameter names and values. So here is our data structure that arranges the names and values to suit the template above, where values for `formulas` have `[]#&=+` pre-percent encoded (although only `+` appears in this example): From f4c2f93f8ba0797f867de8493a0ad74d08dcaf69 Mon Sep 17 00:00:00 2001 From: "Henry H. Andrews" Date: Sat, 15 Jun 2024 13:54:26 -0700 Subject: [PATCH 32/37] Remove 3.0-specific encoding guidance (3.1.1 adjustment to 3857) These lines were added to clarify in 3.0 what was already fixed properly in 3.1. Remove most of them, but keep (and reword) the explanation of how they correlate with how the Parameter Object fields are used. --- versions/3.1.1.md | 14 ++------------ 1 file changed, 2 insertions(+), 12 deletions(-) diff --git a/versions/3.1.1.md b/versions/3.1.1.md index aab4ae1a2d..dc79ba0f47 100644 --- a/versions/3.1.1.md +++ b/versions/3.1.1.md @@ -1815,18 +1815,8 @@ Field Name | Type | Description See also [Appendix C: Using RFC6570 Implementations](#usingRFC6570Implementations) for additional guidance. -The role of `contentType` with `application/x-www-form-urlencoded` request bodies was not described in detail in version 3.0.3 and earlier of this specification. -To match the intent of these fields and be compatible with version 3.1 of this specification, it is RECOMMENDED that whenever any of `style`, `explode`, or `allowReserved` are present with an explicit value: - -* The value of `contentType`, whether it is explicitly defined or has the default value, is to be ignored -* If any of `style`, `explode`, or `allowReserved` are _not_ present with explicit values, then they are to be treated as if they were present with their default values - -However, if all three of `style`, `explode`, and `allowReserved` fields are absent, it is RECOMMENDED that: - -* All three keywords are to be entirely ignored, rather than treated as having their default values -* Encoding is to be based on `contentType` alone, whether it is present with an explicit value or absent and treated as having its default value - -This makes the presence of at least one of `style`, `explode`, or `allowReserved` with an explicit value equivalent to using `schema` with `in: query` Parameter Objects, and their absence the equivalent of using `content`, but with the media type specified in `contentType` rather than through a Media Type Object. +Note that the presence of at least one of `style`, `explode`, or `allowReserved` with an explicit value is equivalent to using `schema` with `in: query` Parameter Objects. +The absence of all three of those fields is the equivalent of using `content`, but with the media type specified in `contentType` rather than through a Media Type Object. ###### Encoding `multipart` Media Types From 70df1b32db518061049df05c5752a30578b78e3e Mon Sep 17 00:00:00 2001 From: "Henry H. Andrews" Date: Sat, 15 Jun 2024 09:38:14 -0700 Subject: [PATCH 33/37] Note RFC6570 issues with form-data (3.1.1 add-on to 3818) OAS 3.1 allows using RFC6570-style serialization with `multipart/form-data`, but this can interact with the requirements of the media type in unexpected and arguably incorrect ways. --- versions/3.1.1.md | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/versions/3.1.1.md b/versions/3.1.1.md index dc79ba0f47..4cd54f5da8 100644 --- a/versions/3.1.1.md +++ b/versions/3.1.1.md @@ -4218,6 +4218,10 @@ Implementations of this specification MAY use an implementation of RFC6570 to pe Note that when using `style: form` RFC6570 expansion to produce an `application/x-www-form-urlencoded` HTTP message body, it is necessary to remove the `?` prefix that is produced to satisfy the URI query string syntax. +When using `style` and similar keywords to produce a `multipart/form-data` body, the query string names are placed in the `name` parameter to the `Content-Disposition` part header, and the values are placed in the corresponding part body; the `?`, `=`, and `&` characters are not used. +Note that while [RFC7578](https://datatracker.ietf.org/doc/html/rfc7578) allows using RFC3986 percent-encoding in "file names", it does not otherwise address the use of percent-encoding within the format. +RFC7578 discusses character set and encoding issues for `multipart/form-data` in detail, and it is RECOMMENDED that OpenAPI Description authors read this guidance carefully before deciding to use RFC6570-based serialization with this media type. + Note also that not all RFC6570 implementations support all four levels of operators, all of which are needed to fully support the OpenAPI Specification's usage. Using an implementation with a lower level of support will require additional manual construction of URI Templates to work around the limitations. From 49d542dc61709e7d09dbe1e132c71c82a918b915 Mon Sep 17 00:00:00 2001 From: "Henry H. Andrews" Date: Sat, 15 Jun 2024 13:56:06 -0700 Subject: [PATCH 34/37] Note issues with encoding form-data (3.1.1 add-on to 3857) In the link to Appendix C, call out that multipart/form-data encoding with `style`, etc. can have problematic interactions with `multipart/form-data`. --- versions/3.1.1.md | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/versions/3.1.1.md b/versions/3.1.1.md index 4cd54f5da8..ef06fd645d 100644 --- a/versions/3.1.1.md +++ b/versions/3.1.1.md @@ -1813,7 +1813,7 @@ Field Name | Type | Description explode | `boolean` | When this is true, property values of type `array` or `object` generate separate parameters for each value of the array, or key-value-pair of the map. For other types of properties this property has no effect. When [`style`](#encodingStyle) is `form`, the default value is `true`. For all other styles, the default value is `false`. Note that despite `false` being the default for `deepObject`, the combination of `false` with `deepObject` is undefined. This property SHALL be ignored if the request body media type is not `application/x-www-form-urlencoded` or `multipart/form-data`. If a value is explicitly defined, then the value of [`contentType`](#encodingContentType) (implicit or explicit) SHALL be ignored. allowReserved | `boolean` | When this is true, parameter values are serialized using reserved expansion, as defined by [RFC6570](https://datatracker.ietf.org/doc/html/rfc6570#autoid-20), which allows [RFC3986's reserved character set](https://datatracker.ietf.org/doc/html/rfc3986#autoid-13), as well as percent-encoded triples, to pass through unchanged, while still percent-encoding all other disallowed characters (including `%` outside of percent-encoded triples). Applications are still responsible for percent-encoding reserved characters that are [not allowed in the query string](https://datatracker.ietf.org/doc/html/rfc3986#autoid-24) (`[`, `]`, `#`), or have a special meaning in `application/x-www-form-urlencoded` (`-`, `&`, `+`); see Appendices [C](#usingRFC6570Implementations) and [E](#percentEncodingAndFormMediaTypes) for details. The default value is `false`. This property SHALL be ignored if the request body media type is not `application/x-www-form-urlencoded` or `multipart/form-data`. If a value is explicitly defined, then the value of [`contentType`](#encodingContentType) (implicit or explicit) SHALL be ignored. -See also [Appendix C: Using RFC6570 Implementations](#usingRFC6570Implementations) for additional guidance. +See also [Appendix C: Using RFC6570 Implementations](#usingRFC6570Implementations) for additional guidance, including on difficulties caused by the interaction between RFC6570's percent-encoding rules and the `multipart/form-data` media type. Note that the presence of at least one of `style`, `explode`, or `allowReserved` with an explicit value is equivalent to using `schema` with `in: query` Parameter Objects. The absence of all three of those fields is the equivalent of using `content`, but with the media type specified in `contentType` rather than through a Media Type Object. From 31d23da8dc55d13c4cd16e15b07194df376dbc7f Mon Sep 17 00:00:00 2001 From: "Henry H. Andrews" Date: Sat, 15 Jun 2024 16:24:16 -0700 Subject: [PATCH 35/37] Migrate 3.0 format guidance to content* (3.1.1 port add-on) Various updates ported over from 3.0.4 mention using the `format` values `byte` or `binary`, which have been replaced by the `contentMediaType` and `contentEncoding` keywords. This change updates those ported chagnes accordingly. --- versions/3.1.1.md | 33 +++++++++++++++++++-------------- 1 file changed, 19 insertions(+), 14 deletions(-) diff --git a/versions/3.1.1.md b/versions/3.1.1.md index ef06fd645d..5827f20992 100644 --- a/versions/3.1.1.md +++ b/versions/3.1.1.md @@ -1751,17 +1751,20 @@ requestBody: type: object properties: {} profileImage: - # Content-Type for properties with type string and contentEncoding is `application/octet-stream` + # default Content-Type for properties with type string and a contentEncoding + # is `application/octet-stream`, so `image/png` must be set using contentMediaType type: string contentMediaType: image/png contentEncoding: base64 children: - # default Content-Type for arrays is based on the _inner_ type (`text/plain` here) + # default Content-Type for arrays is based on the items subschema type, which + # is a string, producing a default of `text/plain` type: array items: type: string addresses: - # default Content-Type for arrays is based on the _inner_ type (object shown, so `application/json` in this example) + # default Content-Type for arrays is based on the items subschema type, which + # is an object, producing a default of `application/json` type: array items: type: object @@ -1791,17 +1794,18 @@ Field Name | Type | Description This object MAY be extended with [Specification Extensions](#specificationExtensions). -The default values for `contentType` are as follows, where an _n/a_ in the `format` column means that the presence or value of `format` is irrelevant: +The default values for `contentType` are as follows, where an _n/a_ in the `contentEncoding` column means that the presence or value of `contentEncoding` is irrelevant: -Property `type` | Property `format` | Default `contentType` -------------- | --------------- | --------------------- -`string` | `binary` | `application/octet-stream` -`string` | _none, or any except `binary`_ | `text/plain` +Property `type` | Property `contentEncoding` | Default `contentType` +--------------- | -------------------------- | --------------------- +_absent_ | _n/a_ | `application/octet-stream` +`string` | _present_ | `application/octet-stream` +`string` | _absent_ | `text/plain` `number`, `integer`, or `boolean` | _n/a_ | `text/plain` `object` | _n/a_ | `application/json` -`array` | _n/a_ | according to the `type` and `format` of the `items` schema +`array` | _n/a_ | according to the `type` of the `items` schema -Determining how to handle `null` values if `nullable: true` is present depends on how `null` values are being serialized. +Determining how to handle a `type` value of `null` depends on how `null` values are being serialized. If `null` values are entirely omitted, then the `contentType` is irrelevant. See [Appendix B](#dataTypeConversion) for a discussion of data type conversion options. @@ -1830,8 +1834,8 @@ It is not currently possible to correlate schema properties with unnamed, ordere Note that there are significant restrictions on what headers can be used with `multipart` media types in general ([RFC2046 §5.1](https://www.rfc-editor.org/rfc/rfc2046.html#section-5.1)) and `multi-part/form-data` in particular ([RFC7578 §4.8](https://www.rfc-editor.org/rfc/rfc7578.html#section-4.8)). Note also that `Content-Transfer-Encoding` is deprecated for `multipart/form-data` ([RFC7578 §4.7](https://www.rfc-editor.org/rfc/rfc7578.html#section-4.7)) where binary data is supported, as it is in HTTP. -Using `format: byte` for a multipart field is equivalent to setting `Content-Transfer-Encoding: base64`. -If `format: byte` is used along with setting a different `Content-Transfer-Encoding` value with the `headers` field, the result is undefined. +Using `contentEncoding` is equivalent to setting `Content-Transfer-Encoding` to the same value. +If `contentEncoding` is used along with setting a different `Content-Transfer-Encoding` value with the `headers` field, the result is undefined. ##### Encoding Object Example @@ -4200,7 +4204,7 @@ To control the serialization of numbers, booleans, and `null` (or other values R The resulting strings would not require any further type conversion. The `format` keyword can assist in serialization. -Some formats (such as `date-time` or `byte`) are unambiguous, while others (such as [`decimal`](https://spec.openapis.org/registry/format/decimal.html) in the [Format Registry](https://spec.openapis.org/registry/format/)) are less clear. +Some formats (such as `date-time`) are unambiguous, while others (such as [`decimal`](https://spec.openapis.org/registry/format/decimal.html) in the [Format Registry](https://spec.openapis.org/registry/format/)) are less clear. However, care must be taken with `format` to ensure that the specific formats are supported by all relevant tools as unrecognized formats are ignored. Requiring input as pre-formatted, schema-validated strings also improves round-trip interoperability as not all programming languages and environments support the same data types. @@ -4453,8 +4457,9 @@ This will expand to the result: RFC6570's percent-encoding behavior is not always appropriate for `in: header` and `in: cookie` parameters. In many cases, it is more appropriate to use `content` with a media type such as `text/plain` and require the application to assemble the correct string. -For both cookies ([RFC6265](https://www.rfc-editor.org/rfc/rfc6265)) and HTTP headers using the structured fields ([RFC8941](https://www.rfc-editor.org/rfc/rfc8941)) syntax, non-ASCII content is handled using base64 encoding (`format: byte`). +For both cookies ([RFC6265](https://www.rfc-editor.org/rfc/rfc6265)) and HTTP headers using the structured fields ([RFC8941](https://www.rfc-editor.org/rfc/rfc8941)) syntax, non-ASCII content is handled using base64 encoding (`contentEncoding: base64`). Note that the standard base64 encoding alphabet includes non-URL-safe characters that are percent-encoded by RFC6570 expansion; serializing values through both encodings is NOT RECOMMENDED. +While `contentEncoding` also supports the `base64url` encoding, which is URL-safe, the header and cookie RFCs do not mention this encoding. Most HTTP headers predate the structured field syntax, and a comprehensive assessment of their syntax and encoding rules is well beyond the scope of this specification. While [RFC8187](https://www.rfc-editor.org/rfc/rfc8187) recommends percent-encoding HTTP field (header or trailer) parameters, these parameters appear after a `;` character. From 4fb5225e84af0ec49973435518caee98070b75cc Mon Sep 17 00:00:00 2001 From: Henry Andrews Date: Thu, 20 Jun 2024 07:39:14 -0700 Subject: [PATCH 36/37] Fix version of JSON Schema cited in change ported from 3.0.4 Co-authored-by: Ralf Handl --- versions/3.1.1.md | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/versions/3.1.1.md b/versions/3.1.1.md index 5827f20992..7dc9bfed92 100644 --- a/versions/3.1.1.md +++ b/versions/3.1.1.md @@ -151,7 +151,7 @@ Patterned fields MUST have unique names within the containing object. In order to preserve the ability to round-trip between YAML and JSON formats, YAML version [1.2](https://yaml.org/spec/1.2/spec.html) is RECOMMENDED along with some additional constraints: -- Tags MUST be limited to those allowed by [YAML's JSON schema ruleset](https://yaml.org/spec/1.2/spec.html#id2803231), which defines a subset of the YAML syntax and is unrelated to [JSON Schema](https://tools.ietf.org/html/draft-wright-json-schema-00). +- Tags MUST be limited to those allowed by [YAML's JSON schema ruleset](https://yaml.org/spec/1.2/spec.html#id2803231), which defines a subset of the YAML syntax and is unrelated to [JSON Schema](https://tools.ietf.org/html/draft-bhutton-json-schema-00). - Keys used in YAML maps MUST be limited to a scalar string, as defined by the [YAML Failsafe schema ruleset](https://yaml.org/spec/1.2/spec.html#id2802346). **Note:** While APIs may be defined by OpenAPI documents in either YAML or JSON format, the API request and response bodies and other content are not required to be JSON or YAML. From 5e8a41b43c74ff7859a3f8c3a77c9f9cd67a5cd4 Mon Sep 17 00:00:00 2001 From: Henry Andrews Date: Thu, 20 Jun 2024 07:41:43 -0700 Subject: [PATCH 37/37] Fix mention of versions in ported text from 3.0.4 Co-authored-by: Ralf Handl --- versions/3.1.1.md | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/versions/3.1.1.md b/versions/3.1.1.md index 7dc9bfed92..ab531b1a41 100644 --- a/versions/3.1.1.md +++ b/versions/3.1.1.md @@ -3417,7 +3417,7 @@ This object MAY be extended with [Specification Extensions](#specificationExtens The `namespace` keyword is intended to match the syntax of [XML namespaces](https://www.w3.org/TR/xml-names11/), although there are a few caveats: -* Version 3.0.3 and earlier of this specification erroneously used the term "absolute URI" instead of "non-relative URI", so authors using namespaces that include a fragment should check tooling support carefully. +* Versions 3.1.0, 3.0.3, and earlier of this specification erroneously used the term "absolute URI" instead of "non-relative URI", so authors using namespaces that include a fragment should check tooling support carefully. * XML allows but discourages relative URI-references, while this specification outright forbids them. * XML 1.1 allows IRIs ([RFC3987](https://datatracker.ietf.org/doc/html/rfc3987)) as namespaces, and specifies that namespaces are compared without any encoding or decoding, which means that IRIs encoded to meet this specification's URI syntax requirement cannot be compared to IRIs as-is.