Using a computed property as a relationship

[cpa]

Hello! I'm struggling to include a computed property as a relationship of my model.
I have the following models:

class Language(BaseModel):
    iso_code = models.CharField(max_length=2)

class Sentence(BaseModel):
    body = models.TextField()
    language = models.ForeignKey(Language)

class Dataset(BaseModel):
    name = models.CharField(max_length=100)
    description = models.TextField()
    sentences = models.ManyToManyField(Sentence, blank=True, related_name='datasets', related_query_name='dataset')

Now, I want my Dataset model to have a Language relationship: it should be the list of all (distinct) languages in the sentences of my dataset.

I tried to add:

    @property
    def get_languages(self, obj):
        return TODO

in my Dataset model definition and

    languages = relations.SerializerMethodResourceRelatedField(
        source='get_languages', many=True, model=Language, read_only=True)

in my DataSerializer, but to no avail (getting AttributeError: 'property' object has no attribute 'parent'). What is the correct way to go? Thanks!

[jerel]

@cpa if your function is a property on the model then you don't want SerializerMethodResourceRelatedField as it is analogous to DRF's SerializerMethodField. You likely want ResourceRelatedField.

If this doesn't solve your issue I can reopen.

[cpa]

Thanks for the answer!
Turns out that ResourceRelatedField doesn't work when many=True, which is my use case. See this PR : #151

[jsenecal]

If you want to work on #151 help yourself :) the original submitter seem to have abandoned the request.

[jerel]

Fixed by #223