Merge pull request #229 from max-arnold/228-runtime-head

add View.head() method at runtime (issue #228)

djangorestframework/compat.py

@@ -65,15 +65,45 @@ except ImportError:
             environ.update(request)
             return WSGIRequest(environ)
 
-# django.views.generic.View (Django >= 1.3)
+# django.views.generic.View (1.3 <= Django < 1.4)
 try:
     from django.views.generic import View
-    if not hasattr(View, 'head'):
+
+    if django.VERSION < (1, 4):
+        from django.utils.decorators import classonlymethod
+        from django.utils.functional import update_wrapper
+
         # First implementation of Django class-based views did not include head method
         # in base View class - https://code.djangoproject.com/ticket/15668
         class ViewPlusHead(View):
-            def head(self, request, *args, **kwargs):
-                return self.get(request, *args, **kwargs)
+            @classonlymethod
+            def as_view(cls, **initkwargs):
+                """
+                Main entry point for a request-response process.
+                """
+                # sanitize keyword arguments
+                for key in initkwargs:
+                    if key in cls.http_method_names:
+                        raise TypeError(u"You tried to pass in the %s method name as a "
+                                        u"keyword argument to %s(). Don't do that."
+                                        % (key, cls.__name__))
+                    if not hasattr(cls, key):
+                        raise TypeError(u"%s() received an invalid keyword %r" % (
+                            cls.__name__, key))
+
+                def view(request, *args, **kwargs):
+                    self = cls(**initkwargs)
+                    if hasattr(self, 'get') and not hasattr(self, 'head'):
+                        self.head = self.get
+                    return self.dispatch(request, *args, **kwargs)
+
+                # take name and docstring from class
+                update_wrapper(view, cls, updated=())
+
+                # and possible attributes set by decorators
+                # like csrf_exempt from dispatch
+                update_wrapper(view, cls.dispatch, assigned=())
+                return view
         View = ViewPlusHead
 
 except ImportError:
@@ -121,6 +151,8 @@ except ImportError:
 
             def view(request, *args, **kwargs):
                 self = cls(**initkwargs)
+                if hasattr(self, 'get') and not hasattr(self, 'head'):
+                    self.head = self.get
                 return self.dispatch(request, *args, **kwargs)
 
             # take name and docstring from class
@@ -154,9 +186,6 @@ except ImportError:
             #)
             return http.HttpResponseNotAllowed(allowed_methods)
 
-        def head(self, request, *args, **kwargs):
-            return self.get(request, *args, **kwargs)
-
 # PUT, DELETE do not require CSRF until 1.4.  They should.  Make it better.
 if django.VERSION >= (1, 4):
     from django.middleware.csrf import CsrfViewMiddleware