Question

I have two models that are linked by another model through a many to many relationship.

Here’s the models themselves

class Posts(models.Model):
    id = models.CharField(max_length=108, primary_key=True)
    tags = models.ManyToManyField('Tags', through='PostTags')


class Tags(models.Model):
    id = models.CharField(max_length=108, primary_key=True)
    posts = models.ManyToManyField('Posts', through='PostTags')

class PostTags(models.Model):
    id = models.CharField(max_length=108, primary_key=True)
    deleted = models.IntegerField()
    post_id = models.ForeignKey('Posts', db_column='post_field')
    tag_id = models.ForeignKey('Tags', db_column='tag_field')

And the tastypie resources

class PostsResource(ModelResource):
    tags = fields.ToManyField('django_app.api.TagsResource', 'tags', null=True)
    class Meta:
        queryset = Posts.objects.filter(deleted=0)
        resource_name = 'posts'

class TagsResource(ModelResource):
    posts = fields.ToManyField('django_app.api.PostsResource', 'posts', null=True)
    class Meta:
        queryset = Tags.objects.filter(deleted=0)
        resource_name = 'tags'

On the posttags table there is a deleted flag, is it possible to only return linked results when the deleted flag in PostTags is 0?

I have tried this filter attribute in tastypie but it only seems to care about the flag in the linked table(ie tags or posts) not the actual table doing the linking.

Answer 1

You can filter fields using lambda bundle attribute showing table name and field name.

tags = fields.ToManyField('django_app.api.TagsResource', attribute=lambda bundle: bundle.obj.tags.filter(tags__deleted=0))