Fix #18991 -- Allow permission lookup by "if perm in perms"

django/contrib/auth/context_processors.py

@@ -32,6 +32,17 @@ def __iter__(self):
         # I am large, I contain multitudes.
         raise TypeError("PermWrapper is not iterable.")
 
+    def __contains__(self, perm_name):
+        """
+        Lookup by "someapp" or "someapp.someperm" in perms.
+        """
+        if '.' not in perm_name:
+            # The name refers to module.
+            return bool(self[perm_name])
+        module_name, perm_name = perm_name.split('.', 1)
+        return self[module_name][perm_name]
+
+
 def auth(request):
     """
     Returns context variables required by apps that use Django's authentication

django/contrib/auth/tests/context_processors.py

@@ -3,20 +3,22 @@
 from django.conf import global_settings
 from django.contrib.auth import authenticate
 from django.contrib.auth.tests.utils import skipIfCustomUser
+from django.contrib.auth.models import User, Permission
+from django.contrib.contenttypes.models import ContentType
 from django.contrib.auth.context_processors import PermWrapper, PermLookupDict
 from django.db.models import Q
 from django.test import TestCase
 from django.test.utils import override_settings
 
 
 class MockUser(object):
-    def has_module_perm(self, perm):
-        if perm == 'mockapp.someapp':
+    def has_module_perms(self, perm):
+        if perm == 'mockapp':
             return True
         return False
 
     def has_perm(self, perm):
-        if perm == 'someperm':
+        if perm == 'mockapp.someperm':
             return True
         return False
 
@@ -40,13 +42,19 @@ def __eq__(self, other):
 
     def test_permwrapper_in(self):
         """
-        Test that 'something' in PermWrapper doesn't end up in endless loop.
+        Test that 'something' in PermWrapper works as expected.
         """
         perms = PermWrapper(MockUser())
-        with self.assertRaises(TypeError):
-            self.EQLimiterObject() in perms
+        # Works for modules and full permissions.
+        self.assertTrue('mockapp' in perms)
+        self.assertFalse('nonexisting' in perms)
+        self.assertTrue('mockapp.someperm' in perms)
+        self.assertFalse('mockapp.nonexisting' in perms)
 
     def test_permlookupdict_in(self):
+        """
+        No endless loops if accessed with 'in' - refs #18979.
+        """
         pldict = PermLookupDict(MockUser(), 'mockapp')
         with self.assertRaises(TypeError):
             self.EQLimiterObject() in pldict
@@ -92,9 +100,28 @@ def test_session_is_accessed(self):
         self.assertContains(response, "Session accessed")
 
     def test_perms_attrs(self):
-        self.client.login(username='super', password='secret')
+        u = User.objects.create_user(username='normal', password='secret')
+        u.user_permissions.add(
+            Permission.objects.get(
+                content_type=ContentType.objects.get_for_model(Permission),
+                codename='add_permission'))
+        self.client.login(username='normal', password='secret')
         response = self.client.get('/auth_processor_perms/')
         self.assertContains(response, "Has auth permissions")
+        self.assertContains(response, "Has auth.add_permission permissions")
+        self.assertNotContains(response, "nonexisting")
+
+    def test_perm_in_perms_attrs(self):
+        u = User.objects.create_user(username='normal', password='secret')
+        u.user_permissions.add(
+            Permission.objects.get(
+                content_type=ContentType.objects.get_for_model(Permission),
+                codename='add_permission'))
+        self.client.login(username='normal', password='secret')
+        response = self.client.get('/auth_processor_perm_in_perms/')
+        self.assertContains(response, "Has auth permissions")
+        self.assertContains(response, "Has auth.add_permission permissions")
+        self.assertNotContains(response, "nonexisting")
 
     def test_message_attrs(self):
         self.client.login(username='super', password='secret')

django/contrib/auth/tests/templates/context_processors/auth_attrs_perm_in_perms.html

@@ -0,0 +1,4 @@
+{% if 'auth' in perms %}Has auth permissions{% endif %}
+{% if 'auth.add_permission' in perms %}Has auth.add_permission permissions{% endif %}
+{% if 'nonexisting' in perms %}nonexisting perm found{% endif %}
+{% if 'auth.nonexisting' in perms %}auth.nonexisting perm found{% endif %}

django/contrib/auth/tests/templates/context_processors/auth_attrs_perms.html

@@ -1 +1,4 @@
 {% if perms.auth %}Has auth permissions{% endif %}
+{% if perms.auth.add_permission %}Has auth.add_permission permissions{% endif %}
+{% if perms.nonexisting %}nonexisting perm found{% endif %}
+{% if perms.auth.nonexisting in perms %}auth.nonexisting perm found{% endif %}

django/contrib/auth/tests/urls.py

@@ -37,6 +37,10 @@ def auth_processor_perms(request):
     return render_to_response('context_processors/auth_attrs_perms.html',
         RequestContext(request, {}, processors=[context_processors.auth]))
 
+def auth_processor_perm_in_perms(request):
+    return render_to_response('context_processors/auth_attrs_perm_in_perms.html',
+        RequestContext(request, {}, processors=[context_processors.auth]))
+
 def auth_processor_messages(request):
     info(request, "Message 1")
     return render_to_response('context_processors/auth_attrs_messages.html',
@@ -58,6 +62,7 @@ def userpage(request):
     (r'^auth_processor_attr_access/$', auth_processor_attr_access),
     (r'^auth_processor_user/$', auth_processor_user),
     (r'^auth_processor_perms/$', auth_processor_perms),
+    (r'^auth_processor_perm_in_perms/$', auth_processor_perm_in_perms),
     (r'^auth_processor_messages/$', auth_processor_messages),
     url(r'^userpage/(.+)/$', userpage, name="userpage"),
 )

docs/releases/1.5.txt

@@ -155,6 +155,10 @@ Django 1.5 also includes several smaller improvements worth noting:
   objects fetched into memory. See :meth:`QuerySet.delete()
   <django.db.models.query.QuerySet.delete>` for details.
 
+* If using :class:`~django.template.RequestContext`, it is now possible to
+  look up permissions by using
+  ``{% if 'someapp.someperm' in perms %}`` in templates.
+
 Backwards incompatible changes in 1.5
 =====================================
 

docs/topics/auth.txt

@@ -1710,6 +1710,20 @@ Thus, you can check permissions in template ``{% if %}`` statements:
         <p>You don't have permission to do anything in the foo app.</p>
     {% endif %}
 
+.. versionadded:: 1.5
+    Permission lookup by "if in".
+
+It is possible to also look permissions up by ``{% if in %}`` statements.
+For example:
+
+.. code-block:: html+django
+
+    {% if 'foo' in perms %}
+        {% if 'foo.can_vote' in perms %}
+            <p>In lookup works, too.</p>
+        {% endif %}
+    {% endif %}
+
 Groups
 ======