public static function ConfigSyncMerger::mergeConfigItemStates in Configuration Synchronizer 8

Merges changes to a configuration item into the active storage.

Parameters

$previous: The configuration item as previously provided (from snapshot).

$current: The configuration item as currently provided by an extension.

$active: The configuration item as present in the active storage.

File

src/ConfigSyncMerger.php, line 22

Class

ConfigSyncMerger

Provides helper functions for merging configuration items.

Namespace

Drupal\config_sync

Code

public static function mergeConfigItemStates(array $previous, array $current, array $active) {

  // We are merging into the active configuration state.
  $result = $active;
  $states = [
    $previous,
    $current,
    $active,
  ];
  $is_associative = FALSE;
  foreach ($states as $array) {

    // Analyze the array to determine if we should preserve integer keys.
    if (Inline::isHash($array)) {

      // If any of the states is associative, treat the item as associative.
      $is_associative = TRUE;
      break;
    }
  }

  // Process associative arrays.
  // Find any differences between previous and current states.
  if ($is_associative) {

    // Detect and process removals.
    $removed = array_diff_key($previous, $current);
    foreach ($removed as $key => $value) {

      // Remove only if unchanged in the active state.
      if (isset($active[$key]) && $active[$key] === $previous[$key]) {
        unset($result[$key]);
      }
    }

    // Detect and handle additions.
    $added = array_diff_key($current, $previous);
    foreach ($added as $key => $value) {

      // Add only if the key hasn't already been set.
      if (!isset($active[$key])) {
        $result[$key] = $value;
      }
    }

    // Detect and process changes.
    foreach ($current as $key => $value) {
      if (isset($previous[$key]) && $previous[$key] !== $value) {

        // If we have an array, recurse.
        if (is_array($value) && is_array($previous[$key]) && isset($active[$key]) && is_array($active[$key])) {
          $result[$key] = self::mergeConfigItemStates($previous[$key], $value, $active[$key]);
        }
        else {

          // Accept the new value only if the item hasn't been customized.
          if (isset($active[$key]) && $active[$key] === $previous[$key]) {
            $result[$key] = $value;
          }
        }
      }
    }
  }
  else {

    // Detect and process removals.
    $removed = array_diff($previous, $current);
    foreach ($removed as $value) {

      // If there is an unchanged value in the active configuration, remove
      // it.
      if (($key = array_search($value, $active, TRUE)) !== FALSE) {
        unset($result[$key]);
      }
    }

    // Detect and process additions.
    $added = array_diff($current, $previous);
    foreach ($added as $value) {
      if (!in_array($value, $result)) {
        $result[] = $value;
      }
    }

    // Keep non-associative.
    $result = array_values($result);
  }
  return $result;
}