Including lists of resources from non-model annotated objects

[RobinRamael]

I have a Organization model with a serializer whose instances get some extra data bound to then when using a specific view. this extra data is two lists of Product objects, which is not a django model (just a plain old python object) but its representation should look like a regular relation: the attrs for the organization and then the product lists in included. I tried the following:

class OrganizationSerializer(serializers.ModelSerializer):
    included_serializers = {
        "current_cycle": ProductSerializer,
        "next_cycle": ProductSerializer,
    }

    current_cycle = ResourceRelatedField(
        many=True, read_only=True, model=Product
    )
    next_cycle = ResourceRelatedField(
        many=True, read_only=True, model=Product
    )

    class Meta:
        model = Organization
        fields = ("pk", "current_cycle", "next_cycle")

    class JSONAPIMeta:
        included_resources = ("current_cycle", "next_cycle")

But this results in AttributeError: type object 'Organization' has no attribute 'current_cycle', which happens in utils.get_related_resource_type.

Stepping through the code there, it seems like although it's checking the model attribute directly on the relation, it's not reaching into the child_relation attr when the many is set to True. It does a child attribute which in my case wasn't there although child_relation is.

Doing a quick and dirty fix by including

    elif (
        hasattr(relation, "child_relation")
        and hasattr(relation.child_relation, "model"
    )):
        relation_model = relation.child_relation.model

in the big if/elif/else in get_related_resource_type seems to work. I'm however bery new to this library and maybe I'm just missing something. Otherwise I can make a PR with this fix, of course. Any help would be greatly appreciated :) Thanks!

[sliverc]

Not 100% certain about your use case, but usually when using a plain python object the resource name should be defined on the serializer itself.

could be something like this:

class ProductSerializer(Seriaizer):
  ...
  class Meta:
    resource_name = 'products'

Does that work for you or still an exception? If there is still an exception please paste the stack trace.

[sliverc]

As there hasn't been any feedback on this I assume this issue has been resolved with above answer and closing this issue therefore. If not please comment.

[nattyg93]

I think I'm running into this. The issue can be reproduced with:

from uuid import uuid4

from django.db import models
from rest_framework_json_api import serializers, utils


class MyModel(models.Model):
    """My model class."""

    created = models.DateTimeField()

    class JSONAPIMeta:
        """JSON:API meta information."""

        resource_name = "my-models"


class NonModel:
    """Non model class."""

    def __init__(self, *, pk=None, my_models):
        """Initialise the variables."""
        if pk is None:
            pk = str(uuid4())
        self.pk = pk
        self.my_models = my_models


class NonModelSerializer(serializers.Serializer):
    """NonModel serializer."""

    my_models = serializers.ResourceRelatedField(
        model=MyModel, queryset=MyModel.objects.all(), many=True
    )

    class JSONAPIMeta:
        """JSON:API meta information."""

        resource_name = "non-models"

    def create(self, validated_data):
        """Return an instance of NonModel."""
        return NonModel(**validated_data)

Using this serializers results in:

APIException: Could not resolve resource type for relation ManyRelatedField(child_relation=ResourceRelatedField(model=<class 'MyModel'>, queryset=<QuerySet []>))

I've worked around the issue by hacking the model onto the ManyRelatedField by adding the following method to the serializer:

    def get_fields(self):
        """Set model on my_models ManyRelatedField."""
        fields = super().get_fields()
        fields["my_models"].model = fields["my_models"].child_relation.model
        return fields

[sliverc]

@nattyg93 Thanks for the example. This could be that this is the issue indeed. I am reopening this issue. PR is welcome.