[Checkins] SVN: z3c.form/trunk/ Make NOT_CHANGED not inherit str.

[Dan Korostelev]

Log message for revision 96360:
  Make NOT_CHANGED not inherit str.
  Check for actual NOT_CHANGED singleton object in the applyChanges instead of equal testing.
  Mention the NOT_CHANGED value as a new feature.
  
  XXX: Should'nt NOT_CHANGED be renamed to NOTCHANGED to follow the same naming style as NOVALUE, while it's not late to do so?

Changed:
  U   z3c.form/trunk/CHANGES.txt
  U   z3c.form/trunk/src/z3c/form/form.py
  U   z3c.form/trunk/src/z3c/form/interfaces.py

-=-
Modified: z3c.form/trunk/CHANGES.txt
===================================================================
--- z3c.form/trunk/CHANGES.txt	2009-02-10 02:25:49 UTC (rev 96359)
+++ z3c.form/trunk/CHANGES.txt	2009-02-10 02:43:09 UTC (rev 96360)
@@ -22,8 +22,14 @@
   - setting (sub)widgets early
   - setting subwidgets.form
 
+- Feature: the new ``z3c.form.interfaces.NOT_CHANGED`` special value
+  is available to signal that the current value should be left as is.
+  It's currently handled in the ``z3c.form.form.applyChanges`` function.
+
 - Feature: When no file is specified in the file upload widget, instead of
   overwriting the value with a missing one, the old data is retained.
+  This is done by returning the new NOT_CHANGED special value from the
+  FileUploadDataConvereter.
 
 - Feature: Added a new flag ``ignoreContext`` to the form field, so that one
   can individually select which fields should and which ones should not ignore

Modified: z3c.form/trunk/src/z3c/form/form.py
===================================================================
--- z3c.form/trunk/src/z3c/form/form.py	2009-02-10 02:25:49 UTC (rev 96359)
+++ z3c.form/trunk/src/z3c/form/form.py	2009-02-10 02:43:09 UTC (rev 96360)
@@ -38,7 +38,7 @@
             continue
         # If the value is NOT_CHANGED, ignore it, since the widget/converter
         # sent a strong message not to do so.
-        if data[name] == interfaces.NOT_CHANGED:
+        if data[name] is interfaces.NOT_CHANGED:
             continue
         # Get the datamanager and get the original value
         dm = zope.component.getMultiAdapter(

Modified: z3c.form/trunk/src/z3c/form/interfaces.py
===================================================================
--- z3c.form/trunk/src/z3c/form/interfaces.py	2009-02-10 02:25:49 UTC (rev 96359)
+++ z3c.form/trunk/src/z3c/form/interfaces.py	2009-02-10 02:43:09 UTC (rev 96360)
@@ -29,10 +29,12 @@
 DISPLAY_MODE = 'display'
 HIDDEN_MODE = 'hidden'
 
-class NOT_CHANGED(str):
+# XXX: should this be changed to NOTCHANGED to follow the
+# same naming style as NOVALUE. 
+class NOT_CHANGED(object):
     def __repr__(self):
         return '<NOT_CHANGED>'
-NOT_CHANGED = NOT_CHANGED()
+NOT_CHANGED = NOT_CHANGED() 
 
 class NOVALUE(object):
     def __repr__(self):