Add add_exception_view

2 files changed, 149 insertions, 0 deletions

diff --git a/pyramid/config/views.py b/pyramid/config/views.py
index 198fde5e8..b13885833 100644
--- a/pyramid/config/views.py
+++ b/pyramid/config/views.py
@@ -1613,6 +1613,71 @@ class ViewsConfiguratorMixin(object):
 
     set_notfound_view = add_notfound_view # deprecated sorta-bw-compat alias
 
+    @viewdefaults
+    @action_method
+    def add_exception_view(
+        self,
+        view=None,
+        context=None,
+        attr=None,
+        renderer=None,
+        wrapper=None,
+        route_name=None,
+        request_type=None,
+        request_method=None,
+        request_param=None,
+        containment=None,
+        xhr=None,
+        accept=None,
+        header=None,
+        path_info=None,
+        custom_predicates=(),
+        decorator=None,
+        mapper=None,
+        match_param=None,
+        **view_options
+            ):
+        """ Add a view for an exception to the current configuration state.
+        The view will be called when Pyramid or application code raises an
+        the given exception.
+
+        .. versionadded:: 1.8
+        """
+        for arg in (
+            'name', 'permission', 'for_', 'http_cache',
+            'require_csrf', 'exception_only',
+        ):
+            if arg in view_options:
+                raise ConfigurationError(
+                    '%s may not be used as an argument to add_exception_view'
+                    % arg
+                    )
+        if context is None:
+            raise ConfigurationError('context exception must be specified')
+        settings = dict(
+            view=view,
+            context=context,
+            wrapper=wrapper,
+            renderer=renderer,
+            request_type=request_type,
+            request_method=request_method,
+            request_param=request_param,
+            containment=containment,
+            xhr=xhr,
+            accept=accept,
+            header=header,
+            path_info=path_info,
+            custom_predicates=custom_predicates,
+            decorator=decorator,
+            mapper=mapper,
+            match_param=match_param,
+            route_name=route_name,
+            permission=NO_PERMISSION_REQUIRED,
+            require_csrf=False,
+            exception_only=True,
+            )
+        return self.add_view(**settings)
+
     @action_method
     def set_view_mapper(self, mapper):
         """
diff --git a/pyramid/tests/test_config/test_views.py b/pyramid/tests/test_config/test_views.py
index c93175ff9..1adde9225 100644
--- a/pyramid/tests/test_config/test_views.py
+++ b/pyramid/tests/test_config/test_views.py
@@ -1847,6 +1847,90 @@ class TestViewsConfigurationMixin(unittest.TestCase):
             config.add_view, view, context=NotAnException, exception_only=True
             )
 
+    def test_add_exception_view(self):
+        from zope.interface import implementedBy
+        from pyramid.interfaces import IRequest
+        from pyramid.renderers import null_renderer
+        view1 = lambda *arg: 'OK'
+        config = self._makeOne(autocommit=True)
+        config.add_exception_view(view=view1, context=Exception, renderer=null_renderer)
+        wrapper = self._getViewCallable(
+            config, ctx_iface=implementedBy(Exception), exception_view=True,
+            )
+        context = Exception()
+        request = self._makeRequest(config)
+        self.assertEqual(wrapper(context, request), 'OK')
+
+    def test_add_exception_view_disallows_name(self):
+        config = self._makeOne(autocommit=True)
+        self.assertRaises(ConfigurationError,
+                          config.add_exception_view,
+                          context=Exception(),
+                          name='foo')
+
+    def test_add_exception_view_disallows_permission(self):
+        config = self._makeOne(autocommit=True)
+        self.assertRaises(ConfigurationError,
+                          config.add_exception_view,
+                          context=Exception(),
+                          permission='foo')
+
+    def test_add_exception_view_disallows_for_(self):
+        config = self._makeOne(autocommit=True)
+        self.assertRaises(ConfigurationError,
+                          config.add_exception_view,
+                          context=Exception(),
+                          for_='foo')
+
+    def test_add_exception_view_disallows_http_cache(self):
+        config = self._makeOne(autocommit=True)
+        self.assertRaises(ConfigurationError,
+                          config.add_exception_view,
+                          context=Exception(),
+                          http_cache='foo')
+
+    def test_add_exception_view_disallows_exception_only(self):
+        config = self._makeOne(autocommit=True)
+        self.assertRaises(ConfigurationError,
+                          config.add_exception_view,
+                          context=Exception(),
+                          exception_only=True)
+
+    def test_add_exception_view_requires_context(self):
+        config = self._makeOne(autocommit=True)
+        view = lambda *a: 'OK'
+        self.assertRaises(ConfigurationError,
+                          config.add_exception_view, view=view)
+
+    def test_add_exception_view_with_view_defaults(self):
+        from pyramid.renderers import null_renderer
+        from pyramid.exceptions import PredicateMismatch
+        from pyramid.httpexceptions import HTTPNotFound
+        from zope.interface import directlyProvides
+        from zope.interface import implementedBy
+        class view(object):
+            __view_defaults__ = {
+                'containment':'pyramid.tests.test_config.IDummy'
+                }
+            def __init__(self, request):
+                pass
+            def __call__(self):
+                return 'OK'
+        config = self._makeOne(autocommit=True)
+        config.add_exception_view(
+            view=view,
+            context=Exception,
+            renderer=null_renderer)
+        wrapper = self._getViewCallable(
+            config, ctx_iface=implementedBy(Exception), exception_view=True)
+        context = DummyContext()
+        directlyProvides(context, IDummy)
+        request = self._makeRequest(config)
+        self.assertEqual(wrapper(context, request), 'OK')
+        context = DummyContext()
+        request = self._makeRequest(config)
+        self.assertRaises(PredicateMismatch, wrapper, context, request)
+
     def test_derive_view_function(self):
         from pyramid.renderers import null_renderer
         def view(request):