Add permission inheritance by parent object. Add ACLs app model tests.

mayan/apps/acls/classes.py

@@ -9,6 +9,8 @@ logger = logging.getLogger(__name__)
 
 class ModelPermission(object):
     _registry = {}
+    _proxies = {}
+    _inheritances = {}
 
     @classmethod
     def register(cls, model, permissions):
@@ -18,6 +20,25 @@ class ModelPermission(object):
 
     @classmethod
     def get_for_instance(cls, instance):
-        permissions = cls._registry.get(type(instance), ())
+        try:
+            permissions = cls._registry[type(instance)]
+        except KeyError:
+            try:
+                permissions = cls._registry[cls._proxies[type(instance)]]
+            except KeyError:
+                permissions = ()
+
         pks = [permission.stored_permission.pk for permission in permissions]
         return StoredPermission.objects.filter(pk__in=pks)
+
+    @classmethod
+    def register_proxy(cls, source, model):
+        cls._proxies[model] = source
+
+    @classmethod
+    def register_inheritance(cls, model, related):
+        cls._inheritances[model] = related
+
+    @classmethod
+    def get_inheritance(cls, model):
+        return cls._inheritances[model]