CODEWITHSUNDEEP
djangodjango-modelstastypie
rh0dium
rh0dium

Reputation: 7032

Tastypie - Linking to a "ForeignKey"

I have two legacy models listed below. The Library.libtype_id is effectively a foreign key to LibraryType when libtype_id > 0. I want to represent this as a ForeignKey Resource in TastyPie when that condition is met.

Can someone help me out? I have seen this but I'm not sure it's the same thing? Thanks much!!

# models.py
class LibraryType(models.Model):
    id = models.AutoField(primary_key=True)
    name = models.CharField(max_length=96)

class Library(models.Model):
    id = models.AutoField(primary_key=True)
    name = models.CharField(max_length=255)
    project = models.ForeignKey('project.Project', db_column='parent')
    libtype_id = models.IntegerField(db_column='libTypeId')

Here is my api.py 

class LibraryTypeResource(ModelResource):

    class Meta:
        queryset = LibraryType.objects.all()
        resource_name = 'library_type'

class LibraryResource(ModelResource):
    project = fields.ForeignKey(ProjectResource, 'project')
    libtype = fields.ForeignKey(LibraryTypeResource, 'libtype_id' )

    class Meta:
        queryset = Library.objects.all()
        resource_name = 'library'
        exclude = ['libtype_id']

    def dehydrate_libtype(self, bundle):
        if getattr(bundle.obj, 'libtype_id', None) != 0:
            return LibraryTypeResource.get_detail(id=bundle.obj.libtype_id)

When I do this however I'm getting the following error on http://0.0.0.0:8001/api/v1/library/?format=json

"error_message": "'long' object has no attribute 'pk'",

Upvotes: 0

Views: 1070

Answers (1)

rockingskier
rockingskier

Reputation: 9346

Shouldn't

libtype = fields.ForeignKey(LibraryTypeResource, 'libtype_id' )

be

libtype = fields.ForeignKey(LibraryTypeResource, 'libtype' )

(without the '_id')

I believe that as it is you are handing the field an int and it is attempting to get the pk from it.

UPDATE:

Missed that libtype_id is an IntegerField, not a ForeignKey (whole point of the question)

Personally I would add a method to the Library to retrieve the LibraryType object. This way you have access to the LibraryType from the Library and you don't have to override any dehydrate methods.

class Library(models.Model):
    # ... other fields
    libtype_id = models.IntegerField(db_column='libTypeId')

    def get_libtype(self):
        return LibraryType.objects.get(id=self.libtype_id)

.

class LibraryResource(ModelResource):
    libtype = fields.ForeignKey(LibraryTypeResource, 'get_libtype')

Upvotes: 1

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