Serializer Method for Open Framework

Question

I have the following Serializer using the Django REST Framework .

This is what I still have ...

serializer.py

class ProductSerializer(serializers.ModelSerializer): score = serializers.SerializerMethodField('get_this_score') class Meta: model = Product fields = ('id', 'title', 'active', 'score') def get_this_score(self, obj): profile = Profile.objects.get(pk=19) score = [val for val in obj.attribute_answers.all() if val in profile.attribute_answers.all()] return (len(score)) 

urls.py

  url(r'^products/(?P<profile_id>.+)/$', ProductListScore.as_view(), name='product-list-score'), 

There are several problems with this piece of code.

1) The stroller pk = 19 is hard-coded, it must be self.kwargs['profile_id']. I tried and tried, but I do not know how to pass kwarg to a method and cannot make profile_id work. that is, I cannot get it from the url.

2) If any of this code is in models? I tried adding to the models, but again I can pass the arguments.

models.py i.e. method class

  def get_score(self, profile): score = [val for val in self.attribute_answers.all() if val in profile.attribute_answers.all()] return len(score) 

Answer 1

Serializers are passed in by a context dictionary that contains an instance of the view, so you can get profile_id by doing something like this:

 view = self.context['view'] profile_id = int(view.kwargs['profile_id']) 

However, in this case, I do not think you need to do this, since in any case, "obj" will be installed in the profile instance.

And yes, you could put the get_this_score method in a model class. You'll still need SerializerMethodField, but it just calls return obj.get_this_score (...), setting any arguments from the serializer context.

Note that in the context of the serializer, "request" will also be included, so you can also access "request.user" if necessary.

Answer 2

To answer Jason’s answer question to Tom’s answer, you can access the request object through the same contextual mechanism as this. You reference query objects from the ModelMethod definition; you do not pass them. I was able to use this to access the current request.user object, as shown below:

 class ProductSerializer(serializers.ModelSerializer): score = serializers.SerializerMethodField('get_this_score') class Meta: model = Product fields = ('id', 'title', 'active', 'score') def get_this_score(self, obj): profile = self.context['request'].user score = [val for val in obj.attribute_answers.all() if val in profile.attribute_answers.all()] return (len(score))