[Checkins] SVN: z3c.form/trunk/src/z3c/form/converter. Fix the converter when the incoming value is an mepty

[Stephan Richter]

Log message for revision 76275:
  Fix the converter when the incoming value is an mepty 
  string. An empty string really means that we have no value 
  and it is thus missing. At least in the UI we cannot easily 
  separate the two.
  

Changed:
  U   z3c.form/trunk/src/z3c/form/converter.py
  U   z3c.form/trunk/src/z3c/form/converter.txt

-=-
Modified: z3c.form/trunk/src/z3c/form/converter.py
===================================================================
--- z3c.form/trunk/src/z3c/form/converter.py	2007-06-04 05:50:34 UTC (rev 76274)
+++ z3c.form/trunk/src/z3c/form/converter.py	2007-06-04 06:19:18 UTC (rev 76275)
@@ -44,6 +44,8 @@
 
     def toFieldValue(self, value):
         """See interfaces.IDataConverter"""
+        if value == u'':
+            return self.field.missing_value
         return self.field.fromUnicode(value)
 
     def __repr__(self):

Modified: z3c.form/trunk/src/z3c/form/converter.txt
===================================================================
--- z3c.form/trunk/src/z3c/form/converter.txt	2007-06-04 05:50:34 UTC (rev 76274)
+++ z3c.form/trunk/src/z3c/form/converter.txt	2007-06-04 06:19:18 UTC (rev 76275)
@@ -42,6 +42,13 @@
   >>> conv.toFieldValue('34')
   34
 
+An empty string means simply that the value is missing and the missing value
+of the field is returned:
+
+  >>> age.missing_value = -1
+  >>> conv.toFieldValue('')
+  -1
+
 Of course, trying to convert a non-integer string representation fails in a
 conversion error: