How to delete all nodes referencing a given one?

Question

I'm working on a catalog based on Drupal Commerce. I have a product display content type referencing product entities. I'm thinking about the ways to make life of a content manager easier.

I made a rule which fires when product is created and creates a corresponding Product display. But I can't figure out the best way to delete a product display nodes when the product is deleted.

Till now I've tried VBO, but seems in Drupal 7 rules2 lacks the ability to run VBO actions.

I guess a quick and dirty solution is to write a module for this task, but I'm looking for something more elegant. Any ideas?

Answer 1

I think a "quick and dirty" module would be the more elegant way. I did something similar recently in drupal 6 with ubercart. I have a content type that sometimes needs to be associated with a product and sometimes doesn't. When one of the custom nodes is deleted, if it has a product associated with it, that needs to be removed as well:

your_module_nodeapi(&$node, $op) {
  if($op == 'delete') {
    $product_nid = db_result(db_query('SELECT nid FROM {content_type_product} WHERE field_product_list = %d', $node->nid));
    if(!empty($product_nid)) {
      node_delete($product_nid);
    }
  }
}

In this case, field_product_list was a node reference field added to the product. I'm sure something similar would work in your case.

Answer 2

Just to add to @David_L's answer, and extending the scenario of the problem.

• The example below makes use of EntityFieldQuery.

• I point out that nested entity references can be handled hook_node_delete() by simply adding another IF, there is no need to write a sub-loop as the hook is called for each deletion.

  <?php
  function mymodule_node_delete($node) {
      if ($node->type == 'product'){// if a product is being deleted
  
          $query = new EntityFieldQuery();
          $result = $query->entityCondition('entity_type', 'node')
                          ->entityCondition('bundle', 'product_display')
                          ->fieldCondition('field_product', 'target_id', $node->nid)
                          ->execute();
          if(!empty($result['node'])){
              $nids = array_keys($result['node']);
              node_delete_multiple($nids);
          }
      }
  
      if ($node->type == 'product_display'){// if a product's display is being deleted
  
          $query = new EntityFieldQuery();
          $result = $query->entityCondition('entity_type', 'node')
                          ->entityCondition('bundle', 'product_display_child')
                          ->fieldCondition('field_product_display', 'target_id', $node->nid)
                          ->execute();
          if(!empty($result['node'])){
              $nids = array_keys($result['node']);
              node_delete_multiple($nids);
          }
      }
  }
  ?>
  

Answer 3

This might not be the best solution but I am using the below: Also, you can do delete mutiple.

    /**
     * Implements hook_node_delete().
     */
    function my_module_node_delete($node) {
      // Gets the node type for the newly deleted node.
      $node_type = $node->type;
      $node_id = $node->nid;
      // Everything happens only if the node is
      // of type mytype.
      if ($node_type == 'mytype') {
        // Find all nodes that reference this node in the custom import reference field.
        // the table name is for the field that keeps the reference.

        $find_nodes = db_select('field_data_field_import_reference', 'f')
          ->fields('f', array('entity_id'))
          ->condition('f.bundle', 'myotherbundle', '=')
          ->condition('f.field_import_reference_target_id', $node_id, '=');

        try {
          // Execute query.
          $resulting_nodes = $find_nodes->execute()->fetchAll();
        }
        catch (Exception $e) {
          // Or catch exception.
          $error_message = $e->getMessage();
          watchdog('mymodule', $error_message);
        }
        // If we have nodes to delete.
        if (isset($resulting_nodes)) {
          // Get the nid for each.
          foreach ($resulting_nodes as $delete_node) {
            // Delete by nid.
            node_delete($delete_node->entity_id);
          }
        }
      }
    }

Answer 4

The following has been borrowed from here.

Insert the following into your custom module.

/**
 * Implements hook_node_delete().
 */
function mymodule_node_delete($node) {
  if ($node->type == 'mynodetype'){
    $nids = db_query('SELECT entity_id FROM {field_data_field_review_reference} WHERE field_review_reference_nid = :nid', array(':nid' => $node->nid))->fetchCol();
    node_delete_multiple($nids);
  }
}