Cakephp 3: how to implement events in helper - cakephp

Question

in Cakephp 3 im trying to implement events in the helper class, this is example of what im trying to do:
protected $_View;
public function __construct(View $View, $config = [])
{
//debug($View);die;
$this->_View = $View;
parent::__construct($View, $config);
$this->_setupEvents();
}
/**
* setup events
*/
protected function _setupEvents() {
$events = [
'filter' => [$this, 'filter'],
];
foreach ($events as $callable) {
$this->_View->eventManager()->on("Helper.Layout.beforeFilter", $callable);
}
}
public function filter(&$content, $options = array()) {
preg_match_all('/\[(menu|m):([A-Za-z0-9_\-]*)(.*?)\]/i', $content, $tagMatches);
for ($i = 0, $ii = count($tagMatches[1]); $i < $ii; $i++) {
$regex = '/(\S+)=[\'"]?((?:.(?![\'"]?\s+(?:\S+)=|[>\'"]))+.)[\'"]?/i';
preg_match_all($regex, $tagMatches[3][$i], $attributes);
$menuAlias = $tagMatches[2][$i];
$options = array();
for ($j = 0, $jj = count($attributes[0]); $j < $jj; $j++) {
$options[$attributes[1][$j]] = $attributes[2][$j];
}
$content = str_replace($tagMatches[0][$i], $this->menu($menuAlias, $options), $content);
}
return $content;
}
But im getting warning for the line where im calling constructor of parent Helper class:
Warning (4096): Argument 1 passed to App\View\Helper\MenusHelper::__construct() must be an instance of App\View\Helper\View, instance of App\View\AppView given, called in C:\wamp\www\CookieCMS\vendor\cakephp\cakephp\src\View\HelperRegistry.php on line 142 and defined [APP/View\Helper\MenusHelper.php, line 26]
Is it possible to implement events in helper this way and what is it that im doing wrong?

Answer 1

The Helper class is already implements EventlistenerInterface, so as explained in the manual all you have to do in your custom helper is return a proper array with required event name to callback mapping from implementedEvents() method.
So something like:
public function implementedEvents()
{
$mapping = parent::implementedEvents();
$mapping += [
'Helper.Layout.beforeFilter' => 'someMethodOfYourHelper',
];
return $mapping;
}