svn commit: r907788 - /subversion/trunk/subversion/bindings/swig/include/proxy.swg

[rd...@apache.org]

Author: rdonch
Date: Mon Feb  8 20:56:13 2010
New Revision: 907788

URL: http://svn.apache.org/viewvc?rev=907788&view=rev
Log:
SWIG/Python: improve the proxy class template, so that the Right Thing is done
with array/hash members on attribute retrieval.

* subversion/bindings/swig/include/proxy.swg:
  (_copy_metadata): New function.
  (<proxy>.__getattr__): Update to use _copy_metadata.


Modified:
    subversion/trunk/subversion/bindings/swig/include/proxy.swg

Modified: subversion/trunk/subversion/bindings/swig/include/proxy.swg
URL: http://svn.apache.org/viewvc/subversion/trunk/subversion/bindings/swig/include/proxy.swg?rev=907788&r1=907787&r2=907788&view=diff
==============================================================================
--- subversion/trunk/subversion/bindings/swig/include/proxy.swg (original)
+++ subversion/trunk/subversion/bindings/swig/include/proxy.swg Mon Feb  8 20:56:13 2010
@@ -28,6 +28,26 @@
  *       that lets us gracefully handle objects that are allocated from
  *       a pool that's been cleared or destroyed.
  */
+ 
+%pythoncode %{
+  def _copy_metadata(value, old_value):
+    import collections
+  
+    if value is None or old_value is None or value is old_value: return
+    
+    if isinstance(value, collections.Mapping):
+      for (k, v) in value:
+        _copy_metadata(v, old_value[k])
+    elif isinstance(value, collections.Sequence):
+      for v, old_v in zip(value, old_value):
+        _copy_metadata(v, old_v)
+    else:
+      try:
+        value.__dict__.update(old_value.__dict__)
+      except AttributeError:
+        pass
+      
+%}
 
 /* Default code for all wrapped proxy classes in Python */
 %define %proxy_pythoncode(TYPE)
@@ -52,18 +72,12 @@
 
     value = _swig_getattr(self, self.__class__, name)
 
-    # Now, if this item has changed, SWIG must have generated a new object.
-    # Copy the pool metadata from the old object over to the new one.
+    # If we got back a different object than we have, we need to copy all our
+    # metadata into it, so that it looks identical
     members = self.__dict__.get("_members")
     if members is not None:
-      old_value = members.get(name)
-      if (old_value is not None and value is not None and
-          value is not old_value):
-        try:
-          value.__dict__.update(old_value.__dict__)
-        except AttributeError:
-          pass
-
+        _copy_metadata(value, members.get(name))
+        
     # Verify that the new object is good
     if hasattr(value, "assert_valid"):
       value.assert_valid()