Initial tests for hyperlinked relationships

rest_framework/fields.py

@@ -4,7 +4,8 @@ import inspect
 import warnings
 
 from django.core import validators
-from django.core.exceptions import ValidationError
+from django.core.exceptions import ObjectDoesNotExist, ValidationError
+from django.core.urlresolvers import resolve
 from django.conf import settings
 from django.utils.encoding import is_protected_type, smart_unicode
 from django.utils.translation import ugettext_lazy as _
@@ -223,9 +224,9 @@ class RelatedField(WritableField):
         into[(self.source or field_name) + '_id'] = self.from_native(value)
 
 
-class ManyRelatedField(RelatedField):
+class ManyRelatedMixin(object):
     """
-    Base class for related model managers.
+    Mixin to convert a related field to a many related field.
     """
     def field_to_native(self, obj, field_name):
         value = getattr(obj, self.source or field_name)
@@ -244,6 +245,15 @@ class ManyRelatedField(RelatedField):
         into[field_name] = [self.from_native(item) for item in value]
 
 
+class ManyRelatedField(ManyRelatedMixin, RelatedField):
+    """
+    Base class for related model managers.
+    """
+    pass
+
+
+### PrimaryKey relationships
+
 class PrimaryKeyRelatedField(RelatedField):
     """
     Serializes a related field or related object to a pk value.
@@ -283,6 +293,83 @@ class ManyPrimaryKeyRelatedField(ManyRelatedField):
         return [self.to_native(item.pk) for item in queryset.all()]
 
 
+### Hyperlinked relationships
+
+class HyperlinkedRelatedField(RelatedField):
+    pk_url_kwarg = 'pk'
+    slug_url_kwarg = 'slug'
+    slug_field = 'slug'
+
+    def __init__(self, *args, **kwargs):
+        try:
+            self.view_name = kwargs.pop('view_name')
+        except:
+            raise ValueError("Hyperlinked field requires 'view_name' kwarg")
+        super(HyperlinkedRelatedField, self).__init__(*args, **kwargs)
+
+    def to_native(self, obj):
+        view_name = self.view_name
+        request = self.context.get('request', None)
+        kwargs = {self.pk_url_kwarg: obj.pk}
+        try:
+            return reverse(view_name, kwargs=kwargs, request=request)
+        except:
+            pass
+
+        slug = getattr(obj, self.slug_field, None)
+
+        if not slug:
+            raise ValidationError('Could not resolve URL for field using view name "%s"', view_name)
+
+        kwargs = {self.slug_url_kwarg: slug}
+        try:
+            return reverse(self.view_name, kwargs=kwargs, request=request)
+        except:
+            pass
+
+        kwargs = {self.pk_url_kwarg: obj.pk, self.slug_url_kwarg: slug}
+        try:
+            return reverse(self.view_name, kwargs=kwargs, request=request)
+        except:
+            pass
+
+        raise ValidationError('Could not resolve URL for field using view name "%s"', view_name)
+
+    def from_native(self, value):
+        # Convert URL -> model instance pk
+        try:
+            match = resolve(value)
+        except:
+            raise ValidationError('Invalid hyperlink - No URL match')
+
+        if match.url_name != self.view_name:
+            raise ValidationError('Invalid hyperlink - Incorrect URL match')
+
+        pk = match.kwargs.get(self.pk_url_kwarg, None)
+        slug = match.kwargs.get(self.slug_url_kwarg, None)
+
+        # Try explicit primary key.
+        if pk is not None:
+            return pk
+        # Next, try looking up by slug.
+        elif slug is not None:
+            slug_field = self.get_slug_field()
+            queryset = self.queryset.filter(**{slug_field: slug})
+        # If none of those are defined, it's an error.
+        else:
+            raise ValidationError('Invalid hyperlink')
+
+        try:
+            obj = queryset.get()
+        except ObjectDoesNotExist:
+            raise ValidationError('Invalid hyperlink - object does not exist.')
+        return obj.pk
+
+
+class ManyHyperlinkedRelatedField(ManyRelatedMixin, HyperlinkedRelatedField):
+    pass
+
+
 class HyperlinkedIdentityField(Field):
     """
     A field that represents the model's identity using a hyperlink.

rest_framework/serializers.py

@@ -422,13 +422,13 @@ class HyperlinkedModelSerializer(ModelSerializer):
     def __init__(self, *args, **kwargs):
         super(HyperlinkedModelSerializer, self).__init__(*args, **kwargs)
         if self.opts.view_name is None:
-            self.opts.view_name = self._get_default_view_name()
+            self.opts.view_name = self._get_default_view_name(self.opts.model)
 
-    def _get_default_view_name(self):
+    def _get_default_view_name(self, model):
         """
         Return the view name to use if 'view_name' is not specified in 'Meta'
         """
-        model_meta = self.opts.model._meta
+        model_meta = model._meta
         format_kwargs = {
             'app_label': model_meta.app_label,
             'model_name': model_meta.object_name.lower()
@@ -437,3 +437,19 @@ class HyperlinkedModelSerializer(ModelSerializer):
 
     def get_pk_field(self, model_field):
         return None
+
+    def get_related_field(self, model_field):
+        """
+        Creates a default instance of a flat relational field.
+        """
+        # TODO: filter queryset using:
+        # .using(db).complex_filter(self.rel.limit_choices_to)
+        rel = model_field.rel.to
+        queryset = rel._default_manager
+        kwargs = {
+            'queryset': queryset,
+            'view_name': self._get_default_view_name(rel)
+        }
+        if isinstance(model_field, models.fields.related.ManyToManyField):
+            return ManyHyperlinkedRelatedField(**kwargs)
+        return HyperlinkedRelatedField(**kwargs)

rest_framework/tests/hyperlinkedserializers.py

@@ -2,7 +2,7 @@ from django.conf.urls.defaults import patterns, url
 from django.test import TestCase
 from django.test.client import RequestFactory
 from rest_framework import generics, status, serializers
-from rest_framework.tests.models import BasicModel
+from rest_framework.tests.models import Anchor, BasicModel, ManyToManyModel
 
 factory = RequestFactory()
 
@@ -17,13 +17,31 @@ class BasicDetail(generics.RetrieveUpdateDestroyAPIView):
     model_serializer_class = serializers.HyperlinkedModelSerializer
 
 
+class AnchorDetail(generics.RetrieveAPIView):
+    model = Anchor
+    model_serializer_class = serializers.HyperlinkedModelSerializer
+
+
+class ManyToManyList(generics.ListAPIView):
+    model = ManyToManyModel
+    model_serializer_class = serializers.HyperlinkedModelSerializer
+
+
+class ManyToManyDetail(generics.RetrieveAPIView):
+    model = ManyToManyModel
+    model_serializer_class = serializers.HyperlinkedModelSerializer
+
+
 urlpatterns = patterns('',
     url(r'^basic/$', BasicList.as_view(), name='basicmodel-list'),
     url(r'^basic/(?P<pk>\d+)/$', BasicDetail.as_view(), name='basicmodel-detail'),
+    url(r'^anchor/(?P<pk>\d+)/$', AnchorDetail.as_view(), name='anchor-detail'),
+    url(r'^manytomany/$', ManyToManyList.as_view(), name='manytomanymodel-list'),
+    url(r'^manytomany/(?P<pk>\d+)/$', ManyToManyDetail.as_view(), name='manytomanymodel-detail'),
 )
 
 
-class TestHyperlinkedView(TestCase):
+class TestBasicHyperlinkedView(TestCase):
     urls = 'rest_framework.tests.hyperlinkedserializers'
 
     def setUp(self):
@@ -45,7 +63,7 @@ class TestHyperlinkedView(TestCase):
         """
         GET requests to ListCreateAPIView should return list of objects.
         """
-        request = factory.get('/')
+        request = factory.get('/basic/')
         response = self.list_view(request).render()
         self.assertEquals(response.status_code, status.HTTP_200_OK)
         self.assertEquals(response.data, self.data)
@@ -54,7 +72,55 @@ class TestHyperlinkedView(TestCase):
         """
         GET requests to ListCreateAPIView should return list of objects.
         """
-        request = factory.get('/1')
+        request = factory.get('/basic/1')
+        response = self.detail_view(request, pk=1).render()
+        self.assertEquals(response.status_code, status.HTTP_200_OK)
+        self.assertEquals(response.data, self.data[0])
+
+
+class TestManyToManyHyperlinkedView(TestCase):
+    urls = 'rest_framework.tests.hyperlinkedserializers'
+
+    def setUp(self):
+        """
+        Create 3 BasicModel intances.
+        """
+        items = ['foo', 'bar', 'baz']
+        anchors = []
+        for item in items:
+            anchor = Anchor(text=item)
+            anchor.save()
+            anchors.append(anchor)
+
+        manytomany = ManyToManyModel()
+        manytomany.save()
+        manytomany.rel.add(*anchors)
+
+        self.data = [{
+            'url': 'http://testserver/manytomany/1/',
+            'rel': [
+                'http://testserver/anchor/1/',
+                'http://testserver/anchor/2/',
+                'http://testserver/anchor/3/',
+            ]
+        }]
+        self.list_view = ManyToManyList.as_view()
+        self.detail_view = ManyToManyDetail.as_view()
+
+    def test_get_list_view(self):
+        """
+        GET requests to ListCreateAPIView should return list of objects.
+        """
+        request = factory.get('/manytomany/')
+        response = self.list_view(request).render()
+        self.assertEquals(response.status_code, status.HTTP_200_OK)
+        self.assertEquals(response.data, self.data)
+
+    def test_get_detail_view(self):
+        """
+        GET requests to ListCreateAPIView should return list of objects.
+        """
+        request = factory.get('/manytomany/1/')
         response = self.detail_view(request, pk=1).render()
         self.assertEquals(response.status_code, status.HTTP_200_OK)
         self.assertEquals(response.data, self.data[0])