class SubProcess in Drupal 8

Runs an array of arrays through its own process pipeline.

The sub_process plugin accepts an array of associative arrays and runs each one through its own process pipeline, producing a newly keyed associative array of transformed values.

Available configuration keys:

• process: the plugin(s) that will process each element of the source.
• key: runs the process pipeline for the key to determine a new dynamic name. If the new dynamic name is NULL then the result of the sub_process pipeline is ignored.
• include_source: (optional) If TRUE, all source plugin configuration and values will be copied into the sub-processed row in a new property named for the source_key configuration value (see below). Defaults to FALSE.
• source_key: (optional) If include_source is TRUE, this is the name of the property of the sub-processed row which will contain the source configuration and values. Ignored if include_source is FALSE. Defaults to 'source' if no value is provided.

Example 1:

This example demonstrates how migration_lookup process plugin can be applied on the following source data.

source: Array
(
  [upload] => Array
    (
      [0] => Array
        (
          [fid] => 1
          [list] => 0
          [description] => "File number 1"
        )
      [1] => Array
        (
          [fid] => 2
          [list] => 1
          [description] => "File number 2"
        )
    )
)
...

The sub_process process plugin will take these arrays one at a time and run its own process for each of them:

process:
  upload:
    plugin: sub_process
    source: upload
    process:
      target_id:
        plugin: migration_lookup
        migration: d6_file
        source: fid
      display: list
      description: description

In this case, each item in the upload array will be processed by the sub_process process plugin. The target_id will be found by looking up the destination value from a previous migration using the migration_lookup process plugin. The display and description fields will be mapped directly.

Example 2.

Drupal 6 filter formats contain a list of filters belonging to that format identified by a numeric delta. A delta of 1 indicates automatic linebreaks, delta of 2 indicates the URL filter and so on. This example demonstrates how static_map process plugin can be applied on the following source data.

source: Array
(
  [format] => 1
  [name] => Filtered HTML
...
  [filters] => Array
    (
      [0] => Array
        (
          [module] => filter
          [delta] => 2
          [weight] => 0
        )
      [1] => Array
        (
          [module] => filter
          [delta] => 0
          [weight] => 1
        )
   )
)
...

The sub_process will take these arrays one at a time and run its own process for each of them:

process:
  filters:
    plugin: sub_process
    source: filters
    process:
      id:
        plugin: static_map
        source:
          - module
          - delta
        map:
          filter:
            0: filter_html_escape
            1: filter_autop
            2: filter_url
            3: filter_htmlcorrector
            4: filter_html_escape
          php:
            0: php_code

The example above means that we take each array element ([0], [1], etc.) from the source filters field and apply the static_map plugin on it. Let's have a closer look at the first array at index 0:

Array
(
   [module] => filter
   [delta] => 2
   [weight] => 0
)

The static_map process plugin results to value 'filter_url' for this input based on the 'module' and 'delta' map.

Example 3.

Normally the array returned from sub_process will have its original keys. If you need to change the key, it is possible for the returned array to be keyed by one of the transformed values in the sub-array. For the same source data used in the previous example, the migration below would result to keys 'filter_2' and 'filter_0'. If the value for 'id' is NULL the result of the sub_process pipeline is ignored.

process:
  filters:
    plugin: sub_process
    source: filters
    key: "@id"
    process:
      id:
        plugin: concat
        source:
          - module
          - delta
        delimiter: _

Plugin annotation

@MigrateProcessPlugin(
  id = "sub_process",
  handle_multiples = TRUE
)

Hierarchy

• class \Drupal\Component\Plugin\PluginBase implements DerivativeInspectionInterface, PluginInspectionInterface
  • class \Drupal\Core\Plugin\PluginBase uses DependencySerializationTrait, MessengerTrait, StringTranslationTrait
    • class \Drupal\migrate\ProcessPluginBase implements MigrateProcessInterface
      • class \Drupal\migrate\Plugin\migrate\process\SubProcess

See also

\Drupal\migrate\Plugin\migrate\process\MigrationLookup

\Drupal\migrate\Plugin\migrate\process\StaticMap

\Drupal\migrate\Plugin\MigrateProcessInterface

1 file declares its use of SubProcess

SubProcessTest.php in core/modules/migrate/tests/src/Unit/process/SubProcessTest.php

File

core/modules/migrate/src/Plugin/migrate/process/SubProcess.php, line 173

Namespace

Drupal\migrate\Plugin\migrate\process

class SubProcess extends ProcessPluginBase {

  /**
   * SubProcess constructor.
   *
   * @param array $configuration
   *   A configuration array containing information about the plugin instance.
   * @param string $plugin_id
   *   The plugin_id for the plugin instance.
   * @param mixed $plugin_definition
   *   The plugin implementation definition.
   */
  public function __construct(array $configuration, $plugin_id, $plugin_definition) {
    $configuration += [
      'include_source' => FALSE,
      'source_key' => 'source',
    ];
    parent::__construct($configuration, $plugin_id, $plugin_definition);
  }

  /**
   * {@inheritdoc}
   */
  public function transform($value, MigrateExecutableInterface $migrate_executable, Row $row, $destination_property) {
    $return = $source = [];
    if ($this->configuration['include_source']) {
      $key = $this->configuration['source_key'];
      $source[$key] = $row
        ->getSource();
    }
    if (is_array($value) || $value instanceof \Traversable) {
      foreach ($value as $key => $new_value) {
        $new_row = new Row($new_value + $source);
        $migrate_executable
          ->processRow($new_row, $this->configuration['process']);
        $destination = $new_row
          ->getDestination();
        if (array_key_exists('key', $this->configuration)) {
          $key = $this
            ->transformKey($key, $migrate_executable, $new_row);
        }

        // Do not save the result if the key is NULL. The configured process
        // pipeline used in transformKey() will return NULL if a
        // MigrateSkipProcessException is thrown.
        // @see \Drupal\filter\Plugin\migrate\process\FilterID
        if ($key !== NULL) {
          $return[$key] = $destination;
        }
      }
    }
    return $return;
  }

  /**
   * Runs the process pipeline for the key to determine its dynamic name.
   *
   * @param string|int $key
   *   The current key.
   * @param \Drupal\migrate\MigrateExecutableInterface $migrate_executable
   *   The migrate executable helper class.
   * @param \Drupal\migrate\Row $row
   *   The current row after processing.
   *
   * @return mixed
   *   The transformed key.
   */
  protected function transformKey($key, MigrateExecutableInterface $migrate_executable, Row $row) {
    $process = [
      'key' => $this->configuration['key'],
    ];
    $migrate_executable
      ->processRow($row, $process, $key);
    return $row
      ->getDestinationProperty('key');
  }

  /**
   * {@inheritdoc}
   */
  public function multiple() {
    return TRUE;
  }

}

Members

Name	Modifiers	Type	Description	Overrides
DependencySerializationTrait::$_entityStorages	protected	property	An array of entity type IDs keyed by the property name of their storages.
DependencySerializationTrait::$_serviceIds	protected	property	An array of service IDs keyed by property name used for serialization.
DependencySerializationTrait::__sleep	public	function		1
DependencySerializationTrait::__wakeup	public	function		2
MessengerTrait::$messenger	protected	property	The messenger.	29
MessengerTrait::messenger	public	function	Gets the messenger.	29
MessengerTrait::setMessenger	public	function	Sets the messenger.
PluginBase::$configuration	protected	property	Configuration information passed into the plugin.	1
PluginBase::$pluginDefinition	protected	property	The plugin implementation definition.	1
PluginBase::$pluginId	protected	property	The plugin_id.
PluginBase::DERIVATIVE_SEPARATOR		constant	A string which is used to separate base plugin IDs from the derivative ID.
PluginBase::getBaseId	public	function	Gets the base_plugin_id of the plugin instance. Overrides DerivativeInspectionInterface::getBaseId
PluginBase::getDerivativeId	public	function	Gets the derivative_id of the plugin instance. Overrides DerivativeInspectionInterface::getDerivativeId
PluginBase::getPluginDefinition	public	function	Gets the definition of the plugin implementation. Overrides PluginInspectionInterface::getPluginDefinition	3
PluginBase::getPluginId	public	function	Gets the plugin_id of the plugin instance. Overrides PluginInspectionInterface::getPluginId
PluginBase::isConfigurable	public	function	Determines if the plugin is configurable.
StringTranslationTrait::$stringTranslation	protected	property	The string translation service.	1
StringTranslationTrait::formatPlural	protected	function	Formats a string containing a count of items.
StringTranslationTrait::getNumberOfPlurals	protected	function	Returns the number of plurals supported by a given language.
StringTranslationTrait::getStringTranslation	protected	function	Gets the string translation service.
StringTranslationTrait::setStringTranslation	public	function	Sets the string translation service to use.	2
StringTranslationTrait::t	protected	function	Translates a string to the current language or to a given language.
SubProcess::multiple	public	function	Indicates whether the returned value requires multiple handling. Overrides ProcessPluginBase::multiple
SubProcess::transform	public	function	Performs the associated process. Overrides ProcessPluginBase::transform
SubProcess::transformKey	protected	function	Runs the process pipeline for the key to determine its dynamic name.
SubProcess::__construct	public	function	SubProcess constructor. Overrides PluginBase::__construct