Dcycle Blog

Removing a field in code

April 07, 2014

Here is a situation that happens once in a while:

  • A new content type is created, where you need a unique nid accross translations (for example, if you have an English and French version of an event, they both need to have nid 1 because other entities reference the entity itself (1) rather than a specific translation of the event).
  • Other content types (pages, for example) can be translated the traditional way (where you have different nids for different languages).
  • To do this, entity translation can be used to make fields translatable, so you create a new translatable-body field just for events.

The above will result in there being two body fields for events, one translatable and one not. If you are using Features and a site deployment module to deploy your site, you can use something like the following code in your site deployment module’s update hooks to remove the superfluous body field instance in the event content type:

 * Remove extra body field from event
function mysite_deploy_update_7212() {
  // this might cause data loss, so it should be done before there
  // is content on production. Extra logic is needed if your have
  // data you need to move from one field instance to another.
  $entity_type = 'node';
  $field_name = 'body';
  $bundle_name = 'event';
  field_delete_instance(field_info_instance($entity_type, $field_name, $bundle_name));
  // before committing this update, make sure the event's body field
  // is removed on your dev environment and update your feature. The
  // following code will revert your feature on target sites, thus
  // ensuring that the field does not remain in your feature, where
  // it can be reintroduced later when other developers update the
  // feature
  features_revert(array('tremblant_feature' => array('node')));
  features_revert(array('tremblant_feature' => array('field_instance')));