full_dehydrate mixin to allow for field selection in Tastypie

full_dehydrateMixin.py

class fieldSelectMixin(object):
    """
    Mixin to allow field selection. full_dehydrate method.
    """
    def full_dehydrate(self, bundle, for_list=False):
        """
        Given a bundle with an object instance, extract the information from it
        to populate the resource.
        """
        use_in = ['all', 'list' if for_list else 'detail']

        # Get values if fields is set in query
        selectedFields = bundle.request.GET.get('fields')

        # If selectedFields has data turn it into a list
        if selectedFields:
            selectedFields = selectedFields.split(',')

        # Dehydrate each field.
        for field_name, field_object in self.fields.items():
            # If it's not for use in this mode, skip
            field_use_in = getattr(field_object, 'use_in', 'all')
            if callable(field_use_in):
                if not field_use_in(bundle):
                    continue
            else:
                if field_use_in not in use_in:
                    continue

            # If fields is set in query paramaters filter field_name
            # and discard any not in selectedFields
            if selectedFields:
                if field_name not in selectedFields:
                    continue

            # A touch leaky but it makes URI resolution work.
            if getattr(field_object, 'dehydrated_type', None) == 'related':
                field_object.api_name = self._meta.api_name
                field_object.resource_name = self._meta.resource_name

            bundle.data[field_name] = field_object.dehydrate(bundle, for_list=for_list)

            # Check for an optional method to do further dehydration.
            method = getattr(self, "dehydrate_%s" % field_name, None)

            if method:
                bundle.data[field_name] = method(bundle)

        bundle = self.dehydrate(bundle)
        return bundle