Am făcut o migrare în Plone.

În upgrades/configure.zcml:

  <genericsetup:upgradeStep
    title="Upgrade my.addon to v3"
    description="Update bla bla items"
    source="2"
    destination="3"
    handler=".update.update_to_3"
    profile="my.addon:default" />

În /profiles/default/metadata.xml:

<version>3</version>

În /upgrades/update.py:

def update_to_3(context):
    logger.info("Upgrading to 3.")

    catalog = portal.get_tool(name='portal_catalog')
    query = {'portal_type': [
        'my.contenttype.blabla',
        'my.contenttype.foobar',
    ]}
    results = catalog.searchResults(**query)
    logger.info('Got %s results.' % len(results))
    items_count = 0

    for brain in results:
        obj = brain.getObject()

        if items_count % 100 == 0:
            logger.info('Went through %s brains' % items_count)
        items_count += 1
        modified = False

        if some_conditions:
            new_value = "something"
            modified = True

        if modified is True:
            logger.info('Updating %s' % obj.absolute_url())
            logger.info("NEW VALUE %s" % new_value)
            obj.blablafield = new_value
            obj.reindexObject()
            obj._p_changed = True
    logger.info("Finished upgrade 3.")

Deschizi /@@overview-controlpanel, mergi la Add-ons, cauți my.addon, rulezi upgrade.

Sau: /manage_main, portal_setup, Upgrades (/portal_setup/manage_upgrades), selectezi profil, show old upgrades, selectezi, rulezi.