function farm_constraint_field_references in farmOS 7

Find all field references to an entity.

Parameters

$type: The entity type.

$id: The entity id.

Return value

array Returns an array of references to the entity.

1 call to farm_constraint_field_references()

farm_constraint_farm_constraint in modules/farm/farm_constraint/farm_constraint.farm_constraint.inc

Implements hook_farm_constraint().

File

modules/farm/farm_constraint/farm_constraint.farm_constraint.inc, line 47

Farm constraint hook implementations.

Code

function farm_constraint_field_references($type, $id) {

  // Start an empty references array.
  $references = array();

  // Define the field types, and entity type that they are used for.
  $field_types = array(
    'entityreference' => array(
      'farm_asset',
      'log',
      'user',
    ),
    'taxonomy_term_reference' => array(
      'taxonomy_term',
    ),
  );

  // Get information about all field instances.
  $instances = field_info_field_map();

  // Iterate through the instances.
  foreach ($instances as $field_name => $instance) {

    // If the field type is not one of the ones we care about, skip it.
    if (!array_key_exists($instance['type'], $field_types)) {
      continue;
    }

    // If the entity type does not match the field type, skip it.
    if (!in_array($type, $field_types[$instance['type']])) {
      continue;
    }

    // Load the field info.
    $field_info = field_info_field($field_name);

    // If this is an entityreference field, and the entity type does not match
    // the field target type, skip it.
    if ($instance['type'] == 'entityreference' && $type != $field_info['settings']['target_type']) {
      continue;
    }

    // Get the database storage details.
    $storage_details = $field_info['storage']['details'];

    // This only works with SQL, so skip if that information isn't available.
    if (empty($storage_details['sql']['FIELD_LOAD_CURRENT'])) {
      continue;
    }

    // Iterate through the database tables and column information. There should
    // only be one of each, so collect information about it.
    $table = '';
    $column = '';
    foreach ($storage_details['sql']['FIELD_LOAD_CURRENT'] as $table_name => $data) {
      $table = $table_name;
      foreach ($data as $key => $column_name) {
        $column = $column_name;
      }
    }

    // If a table and column are not found, skip.
    if (empty($table) || empty($column)) {
      continue;
    }

    // Finally, query the table to see if there are any references to this
    // entity.
    $result = db_query('SELECT entity_type, entity_id FROM {' . $table . '} WHERE ' . $column . ' = :id AND deleted != 1', array(
      ':id' => $id,
    ));

    // Iterate through the results and add the reference to the array.
    foreach ($result as $row) {
      if (!empty($row)) {
        $references[] = array(
          'constraint' => 'field_reference',
          'entity_type' => $row->entity_type,
          'entity_id' => $row->entity_id,
          'field' => $field_name,
          'table' => $table,
          'column' => $column,
        );
      }
    }
  }

  // Return the references array.
  return $references;
}