How and where to write function to use in layout(main.php) in yii2 basic - layout

Question

previously i made a navigation bar in a view page for which i wrote the function in corresponding controller but now i have to put this in main file (layout). But now i don't know where to write the function.
also i have to pass two variable to the layout file through the function that will contain the value of navigation bar.
I have already tried some method but it allows me to return only on value.
Basically i want to know that where can i write the below function to use it in main layout of yii2 basic
public function actionMenutest()
{
$query = new Query;
$data= $query->select('name,id')
->from('menu')->all();
$query2 = new Query;
$data2= $query2->select('name,menu_id')
->from('submenu')->all();
return $this->render('menutest',[
'data'=>$data, 'data2'=>$data2
]);
}

Answer 1

You can use EVENT_BEFORE_RENDER for this purpose. For advanced app the below code need to go into common\config\bootstrap.php file.
use yii\base\Event;
use yii\base\View;
Event::on(View::className(), View::EVENT_BEFORE_RENDER, function() {
$query = new Query;
$data= $query->select('name,id')
->from('menu')->all();
$query2 = new Query;
$data2= $query2->select('name,menu_id')
->from('submenu')->all();
Yii::$app->view->params['data'] = $data;
Yii::$app->view->params['data2'] = $data2;
});
Then in your main layout you can use your model as:
$data= $this->params['data'];
$data2= $this->params['data2'];
I have not used basic template as yet. But you can try the following:
Create a bootstrap.php file in config folder.
After that update the web/index.php file. Put the below code in that:
require(__DIR__ . '/../config/bootstrap.php');
Then put the above code in bootstrap.php file. Try it and let me know if you need any more help.