Using portal_factory

   The portal_factory tool allows users to initiate the creation objects in a
   such a way that if they do not complete an edit form, no object is created in
   the ZODB.  The tool works by creating a temporary object in the request; when
   the request terminates, the object will be garbage collected.

   Configuring portal_factory

      Use the portal_factory's Factory Types ZMI tab to specify the types that
      should be created using portal_factory.  Types must be portal_factory 
      aware for this to work.  In Plone 2.0, the stock CMFDefault types (Document,
      News Item, Event, etc) are all portal_factory aware.  Most types in
      Archetypes should also be portal_factory aware.

   Making Types portal_factory aware

      portal_factory creates a temporary object in the REQUEST.  When the 
      request ends, the object is garbage collected.  If you want to modify an 
      object, you must first instantiate it in the ZODB.  portal_factory 
      provides a utility method that tests an object to see if it is temporary
      and, if so, instantiates it in the proper place in the ZODB.  You can
      invoke this method via::

         portal_factory.doCreate(object, id)
      
      Typically this method will be invoked in the object's edit script via
      code that looks like the following::

         Non-portal_factory-aware code:

         # parameters=id, param1, param2
         context.edit(param1, param2)
         context.plone_utils.contentEdit(context, id=id)
         ...

         portal_factory-aware code:

         # parameters=id, param1, param2
         new_context = portal_factory.doCreate(context, id)
         new_context.edit(param1, param2)
         new_context.plone_utils.contentEdit(new_context, id=id)
         ...

   Working with temporary objects

      You can manipulate temporary objects by using a URL of the form::

         http://myportal/myfolder/portal_factory/TYPE_NAME/OBJECT_ID

      For example, the following URL points to a temporary Document with id foo::

         http://myportal/myfolder/portal_factory/Document/foo

Gotchas 

      If you rename/move your object more than once when saving (move 
      from tempfolder and generate id based on title afterwards) you 
      have to commit a subtransaction to be able to do the second 
      move/rename. Otherwise you will get an error about not being able 
      to copy/move. 

      You commit a subtransaction by doing:: 

         import transaction
         transaction.savepoint(optimistic=True)