Same name and namespace in other branches
  1. 8.9.x core/modules/migrate/src/Plugin/migrate/process/Flatten.php \Drupal\migrate\Plugin\migrate\process\Flatten
  2. 9 core/modules/migrate/src/Plugin/migrate/process/Flatten.php \Drupal\migrate\Plugin\migrate\process\Flatten

Flattens the source value.

The flatten process plugin converts a nested array into a flat array. For example [[1, 2, [3, 4]], [5], 6] becomes [1, 2, 3, 4, 5, 6]. During some types of processing (e.g. user permission splitting), what was once a one-dimensional array gets transformed into a multidimensional array. This plugin will flatten them back down to one-dimensional arrays again.

Example:


process:
  tags:
     -
       plugin: default_value
       source: foo
       default_value: [bar, [alpha, beta]]
     -
       plugin: flatten

In this example, the default_value process returns [bar, [alpha, beta]] (given a NULL value of foo). At this point, Migrate would try to import two items: bar and [alpha, beta]. The latter is not a valid one and won't be imported. We need to pass the values through the flatten processor to obtain a three items array [bar, alpha, beta], suitable for import.

Plugin annotation


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

Hierarchy

  • class \Drupal\migrate\Plugin\migrate\process\Flatten extends \Drupal\migrate\ProcessPluginBase

Expanded class hierarchy of Flatten

See also

\Drupal\migrate\Plugin\MigrateProcessInterface

1 file declares its use of Flatten
FlattenTest.php in core/modules/migrate/tests/src/Unit/process/FlattenTest.php

File

core/modules/migrate/src/Plugin/migrate/process/Flatten.php, line 45

Namespace

Drupal\migrate\Plugin\migrate\process
View source
class Flatten extends ProcessPluginBase {

  /**
   * Flatten nested array values to single array values.
   *
   * For example, [[1, 2, [3, 4]]] becomes [1, 2, 3, 4].
   */
  public function transform($value, MigrateExecutableInterface $migrate_executable, Row $row, $destination_property) {
    if (!is_array($value) && !is_object($value)) {
      $type = gettype($value);
      throw new MigrateException(sprintf("Input should be an array or an object, instead it was of type '%s'", $type));
    }
    return iterator_to_array(new \RecursiveIteratorIterator(new \RecursiveArrayIterator($value)), FALSE);
  }

}

Members

Namesort descending Modifiers Type Description Overrides
Flatten::transform public function Flatten nested array values to single array values.