class Extract

Extracts a value from an array.

The extract process plugin is used to pull data from an input array, which may have multiple levels. One use case is extracting data from field arrays in previous versions of Drupal. For instance, in Drupal 7, a field array would be indexed first by language, then by delta, then finally a key such as 'value'.

Available configuration keys:

• source: The input value - must be an array.
• index: The array of keys to access the value.
• default: (optional) A default value to assign to the destination if the key does not exist.

Examples:

process:
  new_text_field:
    plugin: extract
    source: some_text_field
    index:
      - und
      - 0
      - value

The PHP equivalent of this would be:

$destination['new_text_field'] = $source['some_text_field']['und'][0]['value'];

If a default value is specified, it will be returned if the index does not exist in the input array.

plugin: extract
source: some_text_field
default: 'Default title'
index:
  - title

If $source['some_text_field']['title'] doesn't exist, then the plugin will return "Default title".

Hierarchy

• class \Drupal\Component\Plugin\PluginBase implements \Drupal\Component\Plugin\PluginInspectionInterface, \Drupal\Component\Plugin\DerivativeInspectionInterface
  • class \Drupal\Core\Plugin\PluginBase extends \Drupal\Component\Plugin\PluginBase uses \Drupal\Core\StringTranslation\StringTranslationTrait, \Drupal\Core\DependencyInjection\DependencySerializationTrait, \Drupal\Core\Messenger\MessengerTrait
    • class \Drupal\migrate\ProcessPluginBase extends \Drupal\Core\Plugin\PluginBase implements \Drupal\migrate\Plugin\MigrateProcessInterface
      • class \Drupal\migrate\Plugin\migrate\process\Extract extends \Drupal\migrate\ProcessPluginBase

Expanded class hierarchy of Extract

See also

\Drupal\migrate\Plugin\MigrateProcessInterface

File

core/modules/migrate/src/Plugin/migrate/process/Extract.php, line 61

Namespace

class Extract extends ProcessPluginBase {
    
    /**
     * {@inheritdoc}
     */
    public function transform($value, MigrateExecutableInterface $migrate_executable, Row $row, $destination_property) {
        if (!is_array($value)) {
            throw new MigrateException(sprintf("Input should be an array, instead it was of type '%s'", gettype($value)));
        }
        $new_value = NestedArray::getValue($value, $this->configuration['index'], $key_exists);
        if (!$key_exists) {
            if (array_key_exists('default', $this->configuration)) {
                $new_value = $this->configuration['default'];
            }
            else {
                throw new MigrateException(sprintf("Array index missing, extraction failed for '%s'. Consider adding a `default` key to the configuration.", Variable::export($value)));
            }
        }
        return $new_value;
    }

}

Members