make modification date for media assets editable

git-svn-id: svn://svn.cy55.de/Zope3/src/cybertools/trunk@3230 fd906abe-77d9-0310-91a1-e0d9ade77398

media/interfaces.py

@@ -23,12 +23,19 @@ $Id$
 """
 
 from zope.interface import Interface, Attribute
+from zope.i18nmessageid import MessageFactory
+from zope import schema
 
-from loops.interfaces import IExternalFile
+_ = MessageFactory('cybertools.media')
 
 
 class IMediaAsset(Interface):
 
+    modified = schema.Date(
+                title=_(u'Date'),
+                description=_(u'The date/time the picture was taken.'),
+                required=False,)
+
     def getData(variant=None):
         """ Return the binary data of the media asset or one of its variants.
         """