Triggers an error on duplicate alter listeners.

This is called when the same method is registered for multiple hooks, which are now part of the same alter call.

Parameters

list<string> $hooks: Hook names from the ->alter() call.

string $module: The module name for one of the hook implementations.

string $other_module: The module name for another hook implementation.

callable $listener: The hook listener.

string $identifier: String identifier of the hook listener.

1 call to ModuleHandler::triggerErrorForDuplicateAlterHookListener()

ModuleHandler::getCombinedListeners in core/lib/Drupal/Core/Extension/ModuleHandler.php

Builds a list of implementations for an alter hook.

File

core/lib/Drupal/Core/Extension/ModuleHandler.php, line 560

Class

ModuleHandler

Class that manages modules in a Drupal installation.

Namespace

Drupal\Core\Extension

Code

protected function triggerErrorForDuplicateAlterHookListener(array $hooks, string $module, string $other_module, callable $listener, string $identifier) : void {
  $log_message_replacements = [
    '@implementation' => is_array($listener) ? 'method ' . $identifier . '()' : 'function ' . $listener[1] . '()',
    '@hooks' => "['" . implode("', '", $hooks) . "']",
  ];
  if ($other_module !== $module) {
    // There is conflicting information about which module this
    // implementation is registered for. At this point we cannot even
    // be sure if the module is the one from the main hook or the extra
    // hook. This means that ordering may not work as expected and it is
    // unclear if the intention is to execute the code multiple times. This
    // can be resolved by using a separate method for alter hooks that
    // implement on behalf of other modules.
    trigger_error((string) new FormattableMarkup('The @implementation is registered for more than one of the alter hooks @hooks from the current ->alter() call, on behalf of different modules @module and @other_module. Only one instance will be part of the implementation list for this hook combination. For the purpose of ordering, the module @module will be used.', [
      $log_message_replacements,
      '@module' => "'{$module}'",
      '@other_module' => "'{$other_module}'",
    ]), E_USER_WARNING);
  }
  else {
    // There is no conflict, but probably one or more redundant #[Hook]
    // attributes should be removed.
    trigger_error((string) new FormattableMarkup('The @implementation is registered for more than one of the alter hooks @hooks from the current ->alter() call. Only one instance will be part of the implementation list for this hook combination.', $log_message_replacements), E_USER_NOTICE);
  }
}

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