Changeset 170 for elixir/trunk/elixir/entity.py

Timestamp:

08/01/07 02:05:43 (6 years ago)

Author:

cleverdevil

Message:

First part of moving events into the core of elixir. Next, I will be moving events.py out of ext/ and directly into the elixir namespace.

Files:

• elixir/trunk/elixir/entity.py (modified) (4 diffs)

elixir/trunk/elixir/entity.py

@@ -4 +4 @@
 
 from sqlalchemy                     import Table, Integer, desc
-from sqlalchemy.orm                 import deferred, Query
+from sqlalchemy.orm                 import deferred, Query, MapperExtension
 from sqlalchemy.ext.assignmapper    import assign_mapper
 from sqlalchemy.util                import OrderedDict
@@ -18 +18 @@
 import sys
 import elixir
+import inspect
 
 __pudge_all__ = ['Entity', 'EntityMeta']
@@ -106 +107 @@
             elixir.delayed_entities.add(self)
             return
-
+        
+        self.setup_events()
         self.setup_table()
         self.setup_mapper()
@@ -120 +122 @@
         # finally, allow the statement to do any "finalization"
         Statement.finalize(self.entity)
+    
+    def setup_events(self):
+        # create a list of callbacks for each event
+        methods = {}
+        for name, func in inspect.getmembers(self.entity, inspect.ismethod):
+            if hasattr(func, '_elixir_events'):
+                for event in func._elixir_events:
+                    event_methods = methods.setdefault(event, [])
+                    event_methods.append(func)
+        
+        if not methods:
+            return
+        
+        # transform that list into methods themselves
+        for event in methods:
+            methods[event] = self.make_proxy_method(methods[event])
+        
+        # create a custom mapper extension class, tailored to our entity
+        ext = type('EventMapperExtension', (MapperExtension,), methods)()
+        
+        # then, make sure that the entity's mapper has our mapper extension
+        self.add_mapper_extension(ext)
+    
+    def make_proxy_method(self, methods):
+        def proxy_method(self, mapper, connection, instance):
+            for func in methods:
+                func(instance)
+        return proxy_method
     
     def translate_order_by(self, order_by):