Add a ICustomMigrator interface to the migration framework, which ca…

…n be used

  to register custom migrator adapters. This can be useful to add custom
  migrators to more than one or all content types. For example for
  schemaextenders, which are registered on a interface, which is provided by
  several content types.

CHANGES.rst

@@ -4,6 +4,13 @@ Changelog
 1.2a2 (unreleased)
 ------------------
 
+- Add a ICustomMigrator interface to the migration framework, which can be used
+  to register custom migrator adapters. This can be useful to add custom
+  migrators to more than one or all content types, for example for
+  schemaextenders, which are registered on a interface, which is provided by
+  several content types.
+  [thet]
+
 - In the migration framework, fix queries for Archetype objects, where only
   interfaces are used to skip brains with no or Dexterity meta_type. In some
   cases Dexterity and Archetype objects might provide the same marker

plone/app/contenttypes/migration/configure.zcml

@@ -63,4 +63,6 @@
       name="plone.app.contenttypes.migration.extendedtypes"
       provides="zope.schema.interfaces.IVocabularyFactory" />
 
+  <adapter name="nullmigrator" factory=".migration.BaseCustomMigator"/>
+
 </configure>

plone/app/contenttypes/migration/migration.py

@@ -26,11 +26,16 @@
 from plone.namedfile.file import NamedBlobFile
 from plone.namedfile.file import NamedBlobImage
 from z3c.relationfield import RelationValue
+from zope.component import adapter
+from zope.component import getAdapters
 from zope.component import getUtility
 from zope.event import notify
+from zope.interface import Interface
+from zope.interface import implementer
 from zope.intid.interfaces import IIntIds
 from zope.lifecycleevent import ObjectModifiedEvent
 
+
 import logging
 logger = logging.getLogger(__name__)
 
@@ -191,10 +196,39 @@ def migrate_relatedItems(self):
         self.new._relatedItemsOrder = self.old._relatedItemsOrder
 
 
-class ATCTBaseMigrator(CMFItemMigrator, ReferenceMigrator):
+class ICustomMigrator(Interface):
+    """Adapter implementer interface for custom migrators.
+    Please note that you have to register named adapters in order to be able to
+    register multiple adapters to the same adaptee.
+    """
+    def migrate(old, new):
+        """Start the custom migraton.
+        :param old: The old content object.
+        :param new: The new content object.
+        """
+
+
+@implementer(ICustomMigrator)
+@adapter(Interface)
+class BaseCustomMigator(object):
+    """Base custom migration class. Does nothing.
+
+    You can use this as base class for your custom migrator adapters.
+    You might register it to some specific orginal content interface.
+    """
+    def __init__(self, context):
+        self.context = context
+
+    def migrate(self, old, new):
+        return
+
+
+class ATCTContentMigrator(CMFItemMigrator, ReferenceMigrator):
+    """Base for contentish ATCT
+    """
 
     def __init__(self, *args, **kwargs):
-        super(ATCTBaseMigrator, self).__init__(*args, **kwargs)
+        super(ATCTContentMigrator, self).__init__(*args, **kwargs)
         logger.info(
             "Migrating object %s" %
             '/'.join(self.old.getPhysicalPath())
@@ -204,20 +238,34 @@ def migrate_atctmetadata(self):
         field = self.old.getField('excludeFromNav')
         self.new.exclude_from_nav = field.get(self.old)
 
-
-class ATCTContentMigrator(ATCTBaseMigrator,
-                          CMFItemMigrator,
-                          ReferenceMigrator):
-    """Base for contentish ATCT
-    """
+    def migrate_custom(self):
+        """Get all ICustomMigrator registered migrators and run the migration.
+        """
+        for _, migrator in getAdapters((self.old, ), ICustomMigrator):
+            migrator.migrate(self.old, self.new)
 
 
-class ATCTFolderMigrator(ATCTBaseMigrator,
-                         CMFFolderMigrator,
-                         ReferenceMigrator):
+class ATCTFolderMigrator(CMFFolderMigrator, ReferenceMigrator):
     """Base for folderish ATCT
     """
 
+    def __init__(self, *args, **kwargs):
+        super(ATCTFolderMigrator, self).__init__(*args, **kwargs)
+        logger.info(
+            "Migrating object %s" %
+            '/'.join(self.old.getPhysicalPath())
+        )
+
+    def migrate_atctmetadata(self):
+        field = self.old.getField('excludeFromNav')
+        self.new.exclude_from_nav = field.get(self.old)
+
+    def migrate_custom(self):
+        """Get all ICustomMigrator registered migrators and run the migration.
+        """
+        for _, migrator in getAdapters((self.old, ), ICustomMigrator):
+            migrator.migrate(self.old, self.new)
+
 
 class DocumentMigrator(ATCTContentMigrator):