404 not found on tastypie resource's POST method

I am facing a really strange problem with django-tastypie. Well, this is a bit over complicated so let me start off with the tech stack of my application.

Tech Stack

1. django - Version 1.4.1
2. django-tastypie - Version 0.9.11
3. angularjs - Version 1.0.4

Problem

I have a comment model and two user models Student and Teacher which are derived from subclassing a base user model. Something like the following.

## Base User
class BaseUser(models.Model):
    first_name = models.CharField(max_length=50)
    last_name = models.CharField(max_length=50)
    # some more common fields here

## Teacher Model
class Teacher(BaseUser):
    college = models.ForeignKey(College)


## Student Model
class Student(BaseUser):
    Address = models.OneToOneField(Address)


## Comment Model
class Comment(models.Model):
    date = models.DateTimeField(auto_now_add=True)
    user = models.ForeignKey(backend.models.CustomUser)
    body = models.TextField()
    # Generic Relation with other models
    content_type = models.ForeignKey(ContentType)
    object_id = models.PositiveIntegerField()
    user = generic.GenericForeignKey('content_type', 'object_id')

Now as you can see in my comment model i use GenericForeignKey so that a user can comment on any other model.

I have the resources defined in my tastypie api.py file as follows:

class TeacherResource(BaseModelResource):
    college = fields.ToOneField(CollegeResource, 'college', full=True)

    class Meta(BaseModelResource.Meta):
        queryset = models.Teacher.objects.all()
        resource_name = 'teacher'

    def dehydrate(self, bundle):
        # Add content type url
        ctype = models.ContentType.objects.get_for_model(models.Teacher)
        bundle.data['content_type_id'] = ctype.id
        bundle.data['content_type'] = '/api/v1/contrib/contenttype/%i' % ctype.id
        return bundle


class StudentResource(BaseModelResource):

    class Meta(BaseModelResource.Meta):
        queryset = models.Student.objects.all()
        resource_name = 'student'

    def dehydrate(self, bundle):
        # Add content type url
        ctype = models.ContentType.objects.get_for_model(\
                models.ProspectiveCandidate)
        bundle.data['content_type_id'] = ctype.id
        bundle.data['content_type'] = '/api/v1/contrib/contenttype/%i' % ctype.id
        return bundle


class CommentResource(BaseModelResource):
    custom_user = fields.ToOneField(CustomUserResource,
                                 'custom_user', full=True)
    user = fields.ToOneField(ContentTypeResource, 'content_type')

    class Meta(MarketingResource.Meta):
        queryset = models.Comment.objects.all()
        resource_name = 'comment'
        always_return_data = True
        filtering = {
            'user' : ALL_WITH_RELATIONS,
            'object_id': ALL_WITH_RELATIONS
        }

    def hydrate(self, bundle):
        print bundle.data
        bundle.obj.user = models.ContentType.objects.get_for_id(\
                int(bundle.data['object_id']))
        bundle.obj.object_id = int(bundle.data['object_id'])
        bundle.obj.employee = bundle.request.user.custom_user
        return bundle

    def dehydrate(self, bundle):
        if bundle.obj.date:
            bundle.data['date'] = timesince.timesince(bundle.obj.date)
        return bundle

All the above resources are correctly registered. The GET method for each of the resources work perfectly. I use angularjs' $resource to make calls to the tastypie's REST api. The following is a generic method that i use to send a post request to CommentResource in order to create a new commetn object.

function make_comment(service, scope){
    service.save({
        "user": scope.user.content_type,
        "object_id": scope.user.id,
        "comments": $("textarea#comment").val()
    }, function(data){
        // Success callback Method
        scope.comments.push(data);
    }); 
}

pretty simple eh ? Now in the above method a scope.user can either be a teacher object or a student object and the method simply uses the service to make a POST request with the given data to:

http://127.0.0.1:8000/api/v1/comment

The problem is that when the scope.user is a student object and i call the above method i get a 201 created response but when it is a teacher object it gives me a 404 Not Found error.

Debugging

• I have made sure that the data passed in is correct.
• I have made sure that the teacher object exists.
• I have made sure the contenttype passed in correct.

• The data passed in while using student and teacher objects is pretty similar(which is as follows):

  for a student data passed in and response is:

  data = {'user': '/api/v1/contrib/contenttype/15', 'object_id': '16', 'comments': 'sadfsadfsadfasdf'} response = [19/Mar/2013 18:08:47] "POST /api/v1/comment HTTP/1.1" 201 741

  for a teacher data passed in is:

  data = {'user': '/api/v1/contrib/contenttype/14', 'object_id': '62', 'comments': 'test comment'} response = [19/Mar/2013 18:09:44] "POST /marketing/api/v1/comment HTTP/1.1" 404 3211

I am not able to understand why using the same code would work for one model and not for the other ? Could you please give me some pointers. Thanks.

update

So I was using a custom http error tracking middleware which will send the response as 404 Not Found and when I switched it off i get the following error now.

ContentType matching query does not exist

I looked up the database and the contenttype with id 14 is the Teacher and it is there in the database.