Merge branch 'master' of github.com:Pylons/pyramid

CHANGES.txt

@@ -54,3 +54,7 @@ Features
   result for the view being called. The uri format using an asset spec is 
   package:path/to/template#defname.mako. The old way of returning a tuple 
   from the view is supported for backward compatibility, ('defname', {}).
+
+- When there is a predicate mismatch exception (seen when no view matches for
+  a given request due to predicates not working), the exception now contains
+  a textual description of the predicate which didn't match.

pyramid/config/util.py

@@ -113,6 +113,12 @@ def make_predicates(xhr=None, request_method=None, path_info=None,
     # any predicates get an order of MAX_ORDER, meaning that they will
     # be tried very last.
 
+    # NB: each predicate callable constructed by this function (or examined
+    # by this function, in the case of custom predicates) must leave this
+    # function with a ``__text__`` attribute.  The subsystem which reports
+    # errors when no predicates match depends upon the existence of this
+    # attribute on each predicate callable.
+
     predicates = []
     weights = []
     h = md5()
@@ -273,6 +279,7 @@ def traverse_predicate(context, request):
             tvalue = tgenerate(m) # tvalue will be urlquoted string
             m['traverse'] = traversal_path(tvalue) # will be seq of unicode
             return True
+        traverse_predicate.__text__ = 'traverse matchdict pseudo-predicate'
         # This isn't actually a predicate, it's just a infodict
         # modifier that injects ``traverse`` into the matchdict.  As a
         # result, the ``traverse_predicate`` function above always

pyramid/config/views.py

@@ -276,11 +276,13 @@ def predicated_view(self, view):
         if not predicates:
             return view
         def predicate_wrapper(context, request):
-            if all((predicate(context, request) for predicate in predicates)):
-                return view(context, request)
-            view_name = getattr(view, '__name__', view)
-            raise PredicateMismatch(
-                'predicate mismatch for view %s' % view_name)
+            for predicate in predicates:
+                if not predicate(context, request):
+                    view_name = getattr(view, '__name__', view)
+                    raise PredicateMismatch(
+                         'predicate mismatch for view %s (%s)' % (
+                         view_name, predicate.__text__))
+            return view(context, request)        
         def checker(context, request):
             return all((predicate(context, request) for predicate in
                         predicates))

pyramid/tests/test_config/test_views.py

@@ -2905,14 +2905,16 @@ def test_predicate_mismatch_view_has_no_name(self):
         view = lambda *arg: response
         def predicate1(context, request):
             return False
+        predicate1.__text__ = 'text'
         deriver = self._makeOne(predicates=[predicate1])
         result = deriver(view)
         request = self._makeRequest()
         request.method = 'POST'
         try:
             result(None, None)
         except PredicateMismatch as e:
-            self.assertEqual(e.detail, 'predicate mismatch for view <lambda>')
+            self.assertEqual(e.detail,
+                             'predicate mismatch for view <lambda> (text)')
         else: # pragma: no cover
             raise AssertionError
 
@@ -2921,14 +2923,37 @@ def test_predicate_mismatch_view_has_name(self):
         def myview(request): pass
         def predicate1(context, request):
             return False
+        predicate1.__text__ = 'text'
         deriver = self._makeOne(predicates=[predicate1])
         result = deriver(myview)
         request = self._makeRequest()
         request.method = 'POST'
         try:
             result(None, None)
         except PredicateMismatch as e:
-            self.assertEqual(e.detail, 'predicate mismatch for view myview')
+            self.assertEqual(e.detail,
+                             'predicate mismatch for view myview (text)')
+        else: # pragma: no cover
+            raise AssertionError
+
+    def test_predicate_mismatch_exception_has_text_in_detail(self):
+        from pyramid.exceptions import PredicateMismatch
+        def myview(request): pass
+        def predicate1(context, request):
+            return True
+        predicate1.__text__ = 'pred1'
+        def predicate2(context, request):
+            return False
+        predicate2.__text__ = 'pred2'
+        deriver = self._makeOne(predicates=[predicate1, predicate2])
+        result = deriver(myview)
+        request = self._makeRequest()
+        request.method = 'POST'
+        try:
+            result(None, None)
+        except PredicateMismatch as e:
+            self.assertEqual(e.detail,
+                             'predicate mismatch for view myview (pred2)')
         else: # pragma: no cover
             raise AssertionError
 
@@ -2974,9 +2999,11 @@ def test_with_predicates_notall(self):
         def predicate1(context, request):
             predicates.append(True)
             return True
+        predicate1.__text__ = 'text'
         def predicate2(context, request):
             predicates.append(True)
             return False
+        predicate2.__text__ = 'text'
         deriver = self._makeOne(predicates=[predicate1, predicate2])
         result = deriver(view)
         request = self._makeRequest()