Quart 0.18 & JSONEncoders

[pgjones]

I've removed json_encoders from Quart 0.18 and replaced it with a JSONProvider interface (Flask is doing the same). I'm told this breaks Quart-Motor. Please ask if you need help migrating and thanks for maintaining this extension.

[jeanmonet]

Indeed, Quart-Motor uses following helper:

quart-motor/quart_motor/helpers.py

Line 5 in d2d6291

from quart import abort, json as quart_json

quart-motor/quart_motor/helpers.py

Lines 59 to 96 in d2d6291

	class JSONEncoder(quart_json.JSONEncoder):
	"""A JSON encoder that uses :mod:`bson.json_util` for MongoDB documents.
	.. code-block:: python
	@app.route("/cart/<ObjectId:cart_id>")
	def json_route(cart_id):
	results = mongo.db.carts.find({"_id": cart_id})
	return jsonify(results)
	# returns a Response with JSON body and application/json content-type:
	# '[{"count":12,"item":"egg"},{"count":1,"item":"apple"}]'
	Since this uses PyMongo's JSON tools, certain types may serialize
	differently than you expect. See :class:`~bson.json_util.JSONOptions`
	for details on the particular serialization that will be used.
	A :class:`~quart_motor.helpers.JSONEncoder` is automatically
	automatically installed on the :class:`~quart_motor.Motor`
	instance at creation time, using
	:const:`~bson.json_util.RELAXED_JSON_OPTIONS`. You can change the
	:class:`~bson.json_util.JSONOptions` in use by passing
	``json_options`` to the :class:`~quart_motor.Motor`
	constructor.
	.. note::
	:class:`~bson.json_util.JSONOptions` is only supported as of
	PyMongo version 3.4. For older versions of PyMongo, you will
	have less control over the JSON format that results from calls
	to :func:`~Quart.json.jsonify`.
	.. versionadded:: 2.4.0
	"""
	def __init__(self, json_options, *args, **kwargs):
	"""__init__."""
	if json_options is None:
	json_options = DEFAULT_JSON_OPTIONS
	if json_options is not None:
	self._default_kwargs = {"json_options": json_options}
	else:
	self._default_kwargs = {}
	super(JSONEncoder, self).__init__(*args, **kwargs)

Whereas Quart now uses:

https://github.com/pallets/quart/blob/547578f355b6b9438b08aefbbb65e6446c8290ef/src/quart/json/provider.py#L18-L35

class JSONProvider:
    """A standard set of JSON operations for an application. Subclasses
    of this can be used to customize JSON behavior or use different
    JSON libraries.

    To implement a provider for a specific library, subclass this base
    class and implement at least :meth:`dumps` and :meth:`loads`. All
    other methods have default implementations.

    To use a different provider, either subclass ``Quart`` and set
    :attr:`~quart.Quart.json_provider_class` to a provider class, or set
    :attr:`app.json <quart.Quart.json>` to an instance of the class.
    :param app: An application instance. This will be stored as a
        :class:`weakref.proxy` on the :attr:`_app` attribute.
    """


    def __init__(self, app: Quart) -> None:
        self._app = weakref.proxy(app)

Hoping maintainers can upgrade the code (many thanks to them).

[marirs]

Will have a look this weekend

[jeanmonet]

FYI locally I have made the following changes that seem to work (haven't tested extensively):

# --- helpers.py ---

# class JSONEncoder(quart_json.JSONEncoder):
class JSONEncoder(quart_json.provider.DefaultJSONProvider):
    ...
    def __init__(self, app, json_options, *args, **kwargs):
        #              ^^^  added "app"

# --- __init__.py ---

    # Instead of:
    self._json_encoder = partial(JSONEncoder, json_options=json_options)
    # Replaced with:
    self._json_provider_class = partial(JSONEncoder, json_options=json_options)

    # Instead of:
    app.json_encoder = self._json_encoder
    # Replaced with:
    app.json = self._json_provider_class(app=app)

Attempts to mimic https://github.com/pallets/quart/blob/547578f355b6b9438b08aefbbb65e6446c8290ef/src/quart/app.py#L291

Also, JSONEncoder probably needs to be renamed JSONProvider.

[davideandres95]

@marirs do you still plan on fixing this issue or is the project abandoned?

[JonathanBrenner]

I would also love to have this fixed. Thank you for your work on this project!

[marirs]

Hi all, sorry for the long delay, I'll have this fixed by end of coming week for sure. was so busy in a lot of personal stuff.

[marirs]

Hi @JonathanBrenner @davideandres95 - can you test it. I've released the newer version and let me know.

Thanks to @clementwanjau for taking the time to update this.

[JonathanBrenner]

@marirs The new changes do seem to work for me! I did run into another incompatibility issue with Pymongo 4.0 and opened a pull request to fix it. #6

[marirs]

@JonathanBrenner - Kindly check now, did the merge and update to pypi as well!

Thanks

[JonathanBrenner]

Everything looks good on my end. Thanks @marirs !

[marirs]

Thanks a lot and sorry again for the delay :)

closing this issue finally ;)