Add NamespacedSerializer class

It is able to prepend the view names with a namespace

api/serializers.py

@@ -1,14 +1,35 @@
 # -*- coding: utf-8 -*-
+from django.core.exceptions import ImproperlyConfigured
 from rest_framework import serializers
 
 from booking.models import Duck
 
-class DuckSerializer(serializers.HyperlinkedModelSerializer):
+class NamespacedSerializer(serializers.HyperlinkedModelSerializer):
+    def __init__(self, *args, **kwargs):
+        if not hasattr(self.Meta, 'url_namespace') or self.Meta.url_namespace is None:
+            raise ImproperlyConfigured("namespace must be set!")
+
+        self.url_namespace = self.Meta.url_namespace
+
+        if not self.url_namespace.endswith(':'):
+            self.url_namespace += ':'
+
+        return super(NamespacedSerializer, self).__init__(*args, **kwargs)
+
+    def build_url_field(self, field_name, model_class):
+        field_class, field_kwargs = super(NamespacedSerializer, self) \
+                                    .build_url_field(field_name,
+                                                     model_class)
+
+        view_name = field_kwargs.get('view_name')
+
+        if not view_name.startswith(self.url_namespace):
+            field_kwargs['view_name'] = self.url_namespace + view_name
+
+        return field_class, field_kwargs
+
+class DuckSerializer(NamespacedSerializer):
     class Meta:
+        url_namespace = 'api'
         model = Duck
         fields = ('url', 'name', 'color',)
-        extra_kwargs = {
-            'url': {
-                'view_name': 'api:duck-detail',
-            }
-        }