function ModuleHandler::alter

Overrides ModuleHandlerInterface::alter

File

core/lib/Drupal/Core/Extension/ModuleHandler.php, line 447

Class

ModuleHandler

Class that manages modules in a Drupal installation.

Namespace

Code

public function alter($type, &$data, &$context1 = NULL, &$context2 = NULL) {
    // Most of the time, $type is passed as a string, so for performance,
    // normalize it to that. When passed as an array, usually the first item in
    // the array is a generic type, and additional items in the array are more
    // specific variants of it, as in the case of ['form', 'form_FORM_ID'].
    if (is_array($type)) {
        $cid = implode(',', $type);
    }
    else {
        $cid = $type;
    }
    // Some alter hooks are invoked many times per page request, so store the
    // list of functions to call, and on subsequent calls, iterate through them
    // quickly.
    if (!isset($this->alterEventListeners[$cid])) {
        $hooks = is_array($type) ? array_map(static fn(string $type) => $type . '_alter', $type) : [
            $type . '_alter',
        ];
        $this->alterEventListeners[$cid] = $this->getCombinedListeners($hooks);
    }
    foreach ($this->alterEventListeners[$cid] as $listener) {
        $listener($data, $context1, $context2);
    }
}