How does native Ajax validation work in Yii2?

Question

JavaScript

Let's say I want to check if a field is unique.

In the view I enable enableAjaxValidation:

$form = ActiveForm::begin([
    'id' => 'signup-form',
    'enableAjaxValidation' => true,
]);

In the controller action, I receive an Ajax request:

if (Yii::$app->request->isAjax && $model->load(Yii::$app->request->post())) {
    Yii::$app->response->format = Response::FORMAT_JSON;
    return ActiveForm::validate($model);
}

Okay, that's all clear. But how to process this request now? Who is this ActiveForm::validate($model) returning to?
Naturally, I need to make sure that the data is sent without reloading the page.

Answer 1

To submit form data without reloading the page, hook the event:

$('#signup-form').on('beforeSubmit', function(e){
  console.log('beforeSubmit');
  return false;
});

The beforeSubmit event is called before the form is submitted when all validations have passed.

Answer 2

The request will be processed without your participation, if you have done everything correctly.
Look at the lesson, everything will be clear here https://www.youtube.com/watch?v=URhvUwebSvc