Django Tastypie PATCH throws “'Bundle' object is not iterable” error

Question

I'm working on an API and for one of my endpoints I want to be able to make partial updates.

Here is the tastypie resource

class StoryResource(ModelResource):
    authors = fields.ToManyField(SimpleAuthorResource, 'authors', full=True)
    posts = fields.ToManyField(SimplePostResource, 'posts', full=True, blank=True)
    cover_photo = fields.ForeignKey(PhotoResource, 'cover_photo', full=True)
    class Meta:
        queryset = Story.objects.all()
        resource_name = 'story'
        validation = ModelFormValidation(form_class=StoryForm)
        authorization = Authorization()
        allowed_methods = ['get', 'post', 'patch', 'put']
        ordering = ['-created_ts']
    def determine_format(self, request):
        return "application/json"

And I'm using POSTMAN to make a PATCH request to update a field in the Story model.

It returns with this error:

{"error_message": "'Bundle' object is not iterable", "traceback": "Traceback (most recent call last):\n\n File \"/usr/local/lib/python2.7/dist-packages/tastypie/resources.py\", line 192, in wrapper\n response = callback(request, *args, **kwargs)\n\n File \"/usr/local/lib/python2.7/dist-packages/tastypie/resources.py\", line 406, in dispatch_detail\n return self.dispatch('detail', request, **kwargs)\n\n File \"/usr/local/lib/python2.7/dist-packages/tastypie/resources.py\", line 427, in dispatch\n response = method(request, **kwargs)\n\n File \"/usr/local/lib/python2.7/dist-packages/tastypie/resources.py\", line 1332, in patch_detail\n self.update_in_place(request, bundle, deserialized)\n\n File \"/usr/local/lib/python2.7/dist-packages/tastypie/resources.py\", line 1345, in update_in_place\n self.is_valid(original_bundle, request)\n\n File \"/usr/local/lib/python2.7/dist-packages/tastypie/resources.py\", line 991, in is_valid\n errors = self._meta.validation.is_valid(bundle, request)\n\n File \"/var/www/novella-django/novella/novella/api/validation.py\", line 55, in is_valid\n data[field] = self.uri_to_pk(data[field])\n\n File \"/var/www/novella-django/novella/novella/api/validation.py\", line 29, in uri_to_pk\n for one_uri in uris:\n\nTypeError: 'Bundle' object is not iterable\n"}

I'm not really sure whats wrong and I can't seem to find this bug anywhere else.

Blake Blake · Accepted Answer · 2012-11-09T16:03:08

Sounds like your validation is trying to iterate through your foreign key bundles with this line:

for one_uri in uris:

That's where the "Bundle" object is not iterable is coming from. If you want to iterate over those fields as resource_uris, remove full=True from those FK fields.

If you want to keep them as full=True, you'll need to update your validation to either handle bundles for those fields or exclude them from the validation by using exclude in your form Meta class:

class ModelFormValidation:
    ...

    class Meta:
        exclude = (
            authors,
            posts,
            cover_photo            
        )

Django Tastypie PATCH throws “'Bundle' object is not iterable” error

1 Answers