Altering data during a Drupal 8 Migration

Occasionally you may need to change up the data as it is migrating from your D6 / D7 site to your D8 site.  This is common especially in the case of migrating a Date field.

You can alter a data by extending the ProcessPluginBase and using the transform method.

  1. You should of run the drush version of custom migration and created a module.  We will need to edit one of the config YML files.
  2. In this case we are changing the node import which is usual identified like: migrate_plus.migration.upgrade_d7_node_YOURTYPE.yml
  3. We are going to change our date field in the yml from:

    1. We are changing the process handler to:

  4. In your custom migration module create the following folder path: src/Plugin/migrate/process
    1. Create a file in the new folder called FixDate.php and put this code in: