diff options
Diffstat (limited to 'rest_framework/generics.py')
| -rw-r--r-- | rest_framework/generics.py | 58 |
1 files changed, 34 insertions, 24 deletions
diff --git a/rest_framework/generics.py b/rest_framework/generics.py index e38c52b1..77deb8e4 100644 --- a/rest_framework/generics.py +++ b/rest_framework/generics.py @@ -25,6 +25,7 @@ def strict_positive_int(integer_string, cutoff=None): ret = min(ret, cutoff) return ret + def get_object_or_404(queryset, *filter_args, **filter_kwargs): """ Same as Django's standard shortcut, but make sure to raise 404 @@ -43,6 +44,10 @@ class GenericAPIView(views.APIView): # You'll need to either set these attributes, # or override `get_queryset()`/`get_serializer_class()`. + # If you are overriding a view method, it is important that you call + # `get_queryset()` instead of accessing the `queryset` property directly, + # as `queryset` will get evaluated only once, and those results are cached + # for all subsequent requests. queryset = None serializer_class = None @@ -158,10 +163,11 @@ class GenericAPIView(views.APIView): raise Http404(_("Page is not 'last', nor can it be converted to an int.")) try: page = paginator.page(page_number) - except InvalidPage as e: - raise Http404(_('Invalid page (%(page_number)s): %(message)s') % { - 'page_number': page_number, - 'message': str(e) + except InvalidPage as exc: + error_format = _('Invalid page (%(page_number)s): %(message)s') + raise Http404(error_format % { + 'page_number': page_number, + 'message': str(exc) }) if deprecated_style: @@ -185,7 +191,13 @@ class GenericAPIView(views.APIView): """ Returns the list of filter backends that this view requires. """ - filter_backends = self.filter_backends or [] + if self.filter_backends is None: + filter_backends = [] + else: + # Note that we are returning a *copy* of the class attribute, + # so that it is safe for the view to mutate it if needed. + filter_backends = list(self.filter_backends) + if not filter_backends and self.filter_backend: warnings.warn( 'The `filter_backend` attribute and `FILTER_BACKEND` setting ' @@ -195,12 +207,11 @@ class GenericAPIView(views.APIView): DeprecationWarning, stacklevel=2 ) filter_backends = [self.filter_backend] - return filter_backends + return filter_backends - ######################## - ### The following methods provide default implementations - ### that you may want to override for more complex cases. + # The following methods provide default implementations + # that you may want to override for more complex cases. def get_paginate_by(self, queryset=None): """ @@ -258,6 +269,10 @@ class GenericAPIView(views.APIView): This must be an iterable, and may be a queryset. Defaults to using `self.queryset`. + This method should always be used rather than accessing `self.queryset` + directly, as `self.queryset` gets evaluated only once, and those results + are cached for all subsequent requests. + You may want to override this if you need to provide different querysets depending on the incoming request. @@ -269,8 +284,8 @@ class GenericAPIView(views.APIView): if self.model is not None: return self.model._default_manager.all() - raise ImproperlyConfigured("'%s' must define 'queryset' or 'model'" - % self.__class__.__name__) + error_format = "'%s' must define 'queryset' or 'model'" + raise ImproperlyConfigured(error_format % self.__class__.__name__) def get_object(self, queryset=None): """ @@ -324,12 +339,11 @@ class GenericAPIView(views.APIView): return obj - ######################## - ### The following are placeholder methods, - ### and are intended to be overridden. - ### - ### The are not called by GenericAPIView directly, - ### but are used by the mixin methods. + # The following are placeholder methods, + # and are intended to be overridden. + # + # The are not called by GenericAPIView directly, + # but are used by the mixin methods. def pre_save(self, obj): """ @@ -401,10 +415,8 @@ class GenericAPIView(views.APIView): return ret -########################################################## -### Concrete view classes that provide method handlers ### -### by composing the mixin classes with the base view. ### -########################################################## +# Concrete view classes that provide method handlers +# by composing the mixin classes with the base view. class CreateAPIView(mixins.CreateModelMixin, GenericAPIView): @@ -519,9 +531,7 @@ class RetrieveUpdateDestroyAPIView(mixins.RetrieveModelMixin, return self.destroy(request, *args, **kwargs) -########################## -### Deprecated classes ### -########################## +# Deprecated classes class MultipleObjectAPIView(GenericAPIView): def __init__(self, *args, **kwargs): |