django serialize foreign key objects

starcorn picture starcorn · May 8, 2012 · Viewed 9k times · Source

There are couple of question asking for the same thing already. But they are from 2010, and it didn't help me so much. So I figure it maybe been some update to this front since 2010?

On google I found this link, which explain usage of natural keys. However my problem concerns of getting foreign objects from django.contrib.auth.models.User so it doesn't help.

My problem is as following. I want to serialize the QuerySet so I get the foreign key objects also, because I want to pass it as JSON to the client. The serializer from django.core doesn't do that. So in my case to simply the problem I had added another field to the model to contain the value I need from the foreign object. But it however introduce redundant data.

My example model it contains the username which I would like if possible remove, and instead get it by the foreign key.

    user = models.ForeignKey(User)
    username = models.CharField(max_length=100, null=False)

Answer

bento picture bento · May 9, 2012

One potential way around this is to construct your own dictionary object based on the returns of a queryset. You'd do something like this:

queryset = Model.objects.all()
list = [] #create list
for row in queryset: #populate list
    list.append({'title':row.title, 'body': row.body, 'name': row.user.username})
recipe_list_json = json.dumps(list) #dump list as JSON
return HttpResponse(recipe_list_json, 'application/javascript')

You need to import json for this to work.

import json