How to run custom code on rollback?

Question

I have write a migration class to enter the value in custom table. But I want to know that how to rollback custom table entry.

I used :

public function complete($entity, stdClass $row) {
  // db_insert in my custom table
}

I want to rollback the above changes. For this I tried the completeRollback method below but it is not working.

public function completeRollback($entity_id) {
  dsm($entity_id);
}

Answer 1

You want to use prepareRollback() because at that point the thing that you are rolling back has not been removed yet.

public function prepareRollback($entity_id) {
  parent::prepareRollback();
  // Code to execute before an entity has been rolled back
}

Take a look at this guide for more info.

Answer 2

What I just did for the solutions is, I set the variable in complete function as like :

public function complete($entity, stdClass $row) {
  $migrated_variable = variable_get('migrated_variable', array());
  $migrated_variable[] = $entity->nid;
  variable_set('migrated_variable', $migrated_variable);
}

And used in postRollback function :

  public function postRollback() {
    parent::postRollback();
    $migrated_variable = variable_get('migrated_variable', array());
    foreach ($migrated_variable as $nid) {
      db_delete('custom_table')
        ->condition('nid', $nid)
        ->execute();
    }
    variable_del('migrated_variable');
  }