问题

Context

I have been having conflict. Currenly, I am creating a question answer application. Each question has a tag, and I want to show the most popular tags (e.g. tags that have the most questions associated with it).

Specifics

I am using django-taggit's TaggableManager to do so. Here is the model definition of the Question:

class Question(models.Model):
    tags = TaggableManager()
    date = models.DateTimeField(default=timezone.now)
    text = models.TextField(null=True)

So now I have the several tags attached to questions.

Question

How do I make a tastypie resource to display the tags and sort them by which tag has the most questions associated with it?

My attempts

I have really only had one decently successful attempt at making this work. Here is the tastypie resource:

class TagResource_min(ModelResource):
     def dehydrate(self, bundle):
          bundle.data['total_questions'] len(Question.objects.filter(tags__slug=bundle.obj.slug))
          return bundle  
     class Meta:
          queryset=Tag.objects.all()

Returns a nice JSON with a variable called total_questions with the number of questions associated with it. Although, dehydrate is after the sort_by part of the request cycle specified here, so I cannot sort the resource by total_questions. Here is the JSON:

{

    "meta": {
        "limit": 20,
        "next": null,
        "offset": 0,
        "previous": null,
        "total_count": 13
    },
    "objects": [
        {
            "id": 1,
            "name": "testing tag",
            "resource_uri": "/full/tag/1/",
            "slug": "testing-tag",
            "total_questions": 2
        },
        ...]
}

Another attempt I had went a different way trying to make the queryset be formed from the Question model:

 queryset=Question.objects.filter(~Q(tags__slug=None)).values('tags', 'tags__slug').annotate(total_questions=Count(Tag))

The problem with this was that the filter function turns the result to dict type instead of models.Model type. The key difference was that models.Model has the attribute pk which is a type of identification, and the dict does not have that.

Any contribution is much appriciated! Thank you!

来源：https://stackoverflow.com/questions/41325395/finding-most-popular-tag-taggit-tastypie-django

标签

python