Setting a custom UrlInfo Message on a node triggers an error in collision detection

[marcemarc]

Which Umbraco version are you using? (Please write the exact version, example: 10.1.0)

12.3.3

Bug summary

When you are building an Umbraco site, you are not limited to having Urls generated based on their position in the Umbraco Content Tree, it's possible to manipulate the generation of the Urls by using a custom UrlProvider in combination with an IContentFinder.

In some scenarios with large Umbraco sites you might want to 'hide' a particular node from the Url.

eg if your site had lots of campaign landing pages, all in the root of the site for super SEO ranking points you might want to introduce nodes in the backoffice content tree, to look like folders but which aren't part of the Url, but help editors organise their campaign mess. eg /biscuit-offers/new-custard-cream-sale would become /new-custard-cream-sale and you could achieve this with a custom UrlProvider + IContentFinder to route the page at the root when it's not at the root.

In this scenario or similar, if the editor visited the /biscuit-offers/ node in the backoffice, and switch to info panel they would get the url /biscuit-offers/ but this isn't an actual page! or you would get the message 'this page is published but it is not in the cache'

Anyway you could always tidy this scenario up wtih Umbraco's super flexibility by having something like this in your UrlProvider

if (content.ContentType.Alias == "hiddenFolderDocTypeAlias")
{
 return UrlInfo.Message("A Hidden Folder has no direct Url", culture);
}

With the expectation that this message is shown to the editor in the links section instead of a Url!

But now in V12 latest this blows up!

Stack Trace

'''
at System.Uri.CreateThis(String uri, Boolean dontEscape, UriKind uriKind, UriCreationOptions& creationOptions)
at System.Uri..ctor(String uriString)
at Umbraco.Extensions.UriExtensions.MakeAbsolute(Uri uri, Uri baseUri)
at Umbraco.Extensions.UrlProviderExtensions.DetectCollisionAsync(ILogger logger, IContent content, String url, String culture, IUmbracoContext umbracoContext, IPublishedRouter publishedRouter, ILocalizedTextService textService, IVariationContextAccessor variationContextAccessor, UriUtility uriUtility)
at Umbraco.Extensions.UrlProviderExtensions.GetContentUrlsByCultureAsync(IContent content, IEnumerable1 cultures, IPublishedRouter publishedRouter, IUmbracoContext umbracoContext, IContentService contentService, ILocalizedTextService textService, IVariationContextAccessor variationContextAccessor, ILogger logger, UriUtility uriUtility, IPublishedUrlProvider publishedUrlProvider) at Umbraco.Extensions.UrlProviderExtensions.GetContentUrlsAsync(IContent content, IPublishedRouter publishedRouter, IUmbracoContext umbracoContext, ILocalizationService localizationService, ILocalizedTextService textService, IContentService contentService, IVariationContextAccessor variationContextAccessor, ILogger1 logger, UriUtility uriUtility, IPublishedUrlProvider publishedUrlProvider)
at Umbraco.Cms.Web.BackOffice.Mapping.ContentMapDefinition.GetUrls(IContent source)
at Umbraco.Cms.Web.BackOffice.Mapping.ContentMapDefinition.Map[TVariant](IContent source, ContentItemDisplay1 target, MapperContext context) at Umbraco.Cms.Core.Mapping.UmbracoMapper.<>c__DisplayClass11_02.b__1(Object source, Object target, MapperContext context)
at Umbraco.Cms.Core.Mapping.UmbracoMapper.Map[TTarget](Object source, Type sourceType, MapperContext context)
at Umbraco.Cms.Core.Mapping.UmbracoMapper.Map[TTarget](Object source, MapperContext context)
at Umbraco.Cms.Core.Mapping.UmbracoMapper.Map[TTarget](Object source, Action`1 f)
at Umbraco.Cms.Web.BackOffice.Controllers.ContentController.MapToDisplayWithSchedule(IContent content)
at Umbraco.Cms.Web.BackOffice.Controllers.ContentController.GetById(Int32 id)
at lambda_method899(Closure, Object, Object[])
at Microsoft.AspNetCore.Mvc.Infrastructure.ActionMethodExecutor.SyncObjectResultExecutor.Execute(ActionContext actionContext, IActionResultTypeMapper mapper, ObjectMethodExecutor executor, Object controller, Object[] arguments)
at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.g__Logged|12_1(ControllerActionInvoker invoker)
at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.g__Awaited|10_0(ControllerActionInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted)
at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.Rethrow(ActionExecutedContextSealed context)
at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.Next(State& next, Scope& scope, Object& state, Boolean& isCompleted)
at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.InvokeInnerFilterAsync()
--- End of stack trace from previous location ---
at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.g__Awaited|26_0(ResourceInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted)

'''

Specifics

Digging into this further...

What UrlInfo.Message does (it's an extension method on UrlInfo - https://github.com/umbraco/Umbraco-CMS/blob/contrib/src/Umbraco.Core/Routing/UrlInfo.cs#L80) is create a UrlInfo response from the provider with the text set to be the custom message and with the all-important isUrl flag set to false - so nobody mistakes this as an actual Url and tries to do something 'Urlish' with it...

.... but ....

In the GetContentUrlsByCultureAsync method, for each culture it tries to examine each possible Url and detect any collisions.

Umbraco-CMS/src/Umbraco.Core/Routing/UrlProviderExtensions.cs

Line 107 in c6d0117

private static async Task<IEnumerable<UrlInfo>> GetContentUrlsByCultureAsync(

The PublishedUrlProvider calls GetUrl, to find the UrlInfo objects for the node from the underlying registered UrlProviders... but only returns the 'text' property as a string... not the whole UrlInfo object

then this is passed to DetectCollsionAsync -

Umbraco-CMS/src/Umbraco.Core/Routing/UrlProviderExtensions.cs

Line 156 in c6d0117

Attempt<UrlInfo?> hasCollision = await DetectCollisionAsync(logger, content, url, culture, umbracoContext, publishedRouter, textService, variationContextAccessor, uriUtility);

Attempt<UrlInfo?> hasCollision = await DetectCollisionAsync(logger, content, url, culture, umbracoContext, publishedRouter, textService, variationContextAccessor, uriUtility);

(which ironically returns a list of UrlInfos!)

These 'url strings' are used to see if there is a collision.

If a collision occurs, the collision message is added to the list of returned UrlInfos...
if no collision - a brand new UrlInfo class is constructed from the string url

But the problemtherefore is triggered inside the DetectCollisionAsync method, the first line of code converts the provided Url into a Uri

var uri = new Uri(url.TrimEnd(Constants.CharArrays.ForwardSlash), UriKind.RelativeOrAbsolute);

https://github.com/umbraco/Umbraco-CMS/blob/c6d01178c06a519423b3c37fea7bbdd0e536319f/src/Umbraco.Core/Routing/UrlProviderExtensions.cs#L215C8-L215C103

and when the Text returned from UrlProvider is a custom message 'This is a hidden folder and has no Url' rather than an actual valid routable url, this blows up!

Ways to fix?

The PublishedUrlProvider could have a GetUrlInfos method that returns UrlInfo objects from the underlying UrlProviders, and then the IsUrl property could be used to determine whether or not to detect collisions, eg no need to if isUrl is false, it can just be added to the filtered list of UrlInfos... there won't be a clash from a message!

or

we could Try and parse the Url in DetectCollsionsAsync to see if it's a valid URI, or check for starting with / or something, and again allow anything that isn't a Url to be added as a message...

or have I totally misunderstood the situation!

Happy to have a go at fixing it if it needs to be fixed and if it's not a super breaking change that can't be made til Umbraco 25 etc...

Bizarre workaround

If you set your message to be /a-hidden-folder-has-no-url/ then this gets parsed successfully as a Uri! so you avoid the error, and if you add a further custom IContentFinder, that then routes this specific Url to page not found page... then the message appears as a Url! But you can tidy this up in the EditorSendingContentNotification

Steps to reproduce

Create a Custom UrlProvider for your site (have it inherit DefaultUrlProvider), replace the DefaultUrlProvider with your custom UrlProvider with UmbracoBuilder.

In your custom UrlProvider, check for a particular doctype, and return

UrlInfo.Message("this is not a url", culture);

Then visit that DocType in the backoffice and you'll get the error.

Expected result / actual result

Expected result is to see the Custom Message appear in the Urls section for a page based on the Doc Type you are sending the custom message to.

[github-actions]

Hi there @marcemarc!

Firstly, a big thank you for raising this issue. Every piece of feedback we receive helps us to make Umbraco better.

We really appreciate your patience while we wait for our team to have a look at this but we wanted to let you know that we see this and share with you the plan for what comes next.

• We'll assess whether this issue relates to something that has already been fixed in a later version of the release that it has been raised for.
• If it's a bug, is it related to a release that we are actively supporting or is it related to a release that's in the end-of-life or security-only phase?
• We'll replicate the issue to ensure that the problem is as described.
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We wish we could work with everyone directly and assess your issue immediately but we're in the fortunate position of having lots of contributions to work with and only a few humans who are able to do it. We are making progress though and in the meantime, we will keep you in the loop and let you know when we have any questions.

Thanks, from your friendly Umbraco GitHub bot 🤖 🙂

[elit0451]

Hi @marcemarc 👋

Thank you for the investigation and the information sharing 😁 I managed to reproduce this in the latest Umbraco 10 as well. From "But now in V12 latest this blows up!" it seems like you had this working in another version of Umbraco. Can you clarify which one, so we can figure out if we are dealing with a regression bug?

For now, I will bring this with the team to discuss 🙂 and get back to you either this or next week

---

Notes:

• I managed to reproduce this in v10-v13 with the following setup and snippets:

  • 

  • 

using Microsoft.Extensions.Options;
using Umbraco.Cms.Core.Configuration.Models;
using Umbraco.Cms.Core.Models.PublishedContent;
using Umbraco.Cms.Core.Routing;
using Umbraco.Cms.Core.Services;
using Umbraco.Cms.Core.Web;

namespace Umbraco.Cms.Web.UI;

public class CustomUrlProvider : DefaultUrlProvider
{
    public CustomUrlProvider(
        IOptionsMonitor<RequestHandlerSettings> requestSettings,
        ILogger<DefaultUrlProvider> logger,
        ISiteDomainMapper siteDomainMapper,
        IUmbracoContextAccessor umbracoContextAccessor,
        UriUtility uriUtility,
        ILocalizationService localizationService)
        : base(requestSettings,
            logger,
            siteDomainMapper,
            umbracoContextAccessor,
            uriUtility,
            localizationService)
    {
    }

    public override UrlInfo? GetUrl(IPublishedContent content, UrlMode mode, string? culture, Uri current)
    {
        if (content is null)
        {
            return null;
        }

        // Only apply this to hidden folder pages
        if (content.ContentType.Alias == "hiddenFolder")
        {
            // Get the original base url that the DefaultUrlProvider would have returned,
            // it's important to call this via the base, rather than .Url, or UrlProvider.GetUrl to avoid cyclically calling this same provider in an infinite loop!!)
            UrlInfo? defaultUrlInfo = base.GetUrl(content, mode, culture, current);
            if (defaultUrlInfo is null)
            {
                return null;
            }

            if (!defaultUrlInfo.IsUrl)
            {
                // This is a message (eg published but not visible because the parent is unpublished or similar)
                return defaultUrlInfo;
            }

            // Manipulate the url somehow in a custom fashion:
            return UrlInfo.Message("This is not a url", culture);
        }

        // Otherwise return null
        return null;
    }
}

using Umbraco.Cms.Core.Composing;

namespace Umbraco.Cms.Web.UI;

public class RegisterCustomUrlProviderComposer : IComposer
{
    public void Compose(IUmbracoBuilder builder)
    {
        builder.UrlProviders().Insert<CustomUrlProvider>();
    }
}

[marcemarc]

HI @elit0451
Thanks for taking the time to reproduce.
Looking through git blame, when collision detection was introduced:

Umbraco-CMS/src/Umbraco.Web/Routing/UrlProviderExtensions.cs

Line 20 in 5f8747b

public static IEnumerable<string> GetContentUrls(this IContent content, UmbracoContext umbracoContext)

This would have worked, so around V7 time!
There is a commit Here:
github.com/umbraco/Umbraco-CMS/commit/8561d85f7af4b17681c6d84b5950a787fddabf7e#diff-cd06d5e77b193e5227cafc506b674f6620ba39c5c4f36acd55439db48ae573a0R75
Where the new URI was introduced in a commit that pulls 7.6 into 8....

... so maybe this is broken for a long time!
I guess for this length of time it hasn't affected too many people!

But I think it is meant to be possible to return a UrlInfo Message in a UrlProvider!
But if it's no longer meant to be we could stop the use of the UrlInfo.Message extension method etc

I think my suggested fix might be good though, because then the UrlInfo classes that are returned from the UrlProviders aren't discarded in favour of 'new' constructed UrlInfos!! memory allocation and all that! :-P

regards

Marc

[elit0451]

Hi again 🙂
So, I talked to the team and we agreed that this bug should be fixed. We would like some help with it so I will mark it as up for grabs. We need to make sure that if we create UrlInfo(string text, bool isUrl, string? culture) and isUrl = false we are not trying to make this a routable content

[github-actions]

Hi @marcemarc,

We're writing to let you know that we would love some help with this issue. We feel that this issue is ideal to flag for a community member to work on it. Once flagged here, folk looking for issues to work on will know to look at yours. Of course, please feel free work on this yourself ;-). If there are any changes to this status, we'll be sure to let you know.

For more information about issues and states, have a look at this blog post.

Thanks muchly, from your friendly Umbraco GitHub bot :-)