Content migration of plone dexterity content types in plone 5 - migration

Question

I have a dexterity content type defined as model in Employee.xml.
<model xmlns="http://namespaces.plone.org/supermodel/schema"
xmlns:marshal="http://namespaces.plone.org/supermodel/marshal"
xmlns:i18n="http://xml.zope.org/namespaces/i18n"
i18n:domain="plone">
<schema>
<field name="fullname" type="zope.schema.TextLine">
<description />
<required>True</required>
<title>Firstname and Surname</title>
</field>
<field name="position" type="zope.schema.TextLine">
<description />
<required>True</required>
<title>Position</title>
</field>
</schema>
</model>
Very easy. The class is defined in content.py.
class Employee(Item):
"""Convenience subclass for ``Employee`` portal type
"""
There are some instances of Employee in my database.
Now I want to add a new feature to my content type.
class Employee(Item):
"""Convenience subclass for ``Employee`` portal type
"""
def Title(self):
return self.fullname
Now I can see the fullname of the employee in the folder_contents view. But it works only for instances added after the modification. The "old" content seems to need a migration.
My question: How?
The docs did not help. (https://docs.plone.org/develop/plone/persistency/migrations.html)

Answer 1

The older instances haven't been re-indexed, so everything based on the catalog (collections, navigation, search, folder content, etc.) cannot be aware of their new Title attribute.
Just reindex your portal_catalog and it will be fine.