How to create custom JS event on successful form validation?

Question

Yii

The work of forms can be described in simple two points:
1. Submitting the form
2. Result of form
processing 2 seconds, and the visitor may get the impression that nothing is working.
It is necessary when you click "submit", if the js-validation went well, the form was replaced with a loader-picture, and then, after 1-2 seconds, with the message "your form has been submitted"
I tried to look for where js form validation takes place in Yii2 ... I killed several hours, but did not figure it out. On the other hand, even if I find that, for example, it goes into yii.validation.js, this file cannot be edited, because it is needed to work with all forms.
Has anyone faced a similar problem? How did they decide?

Answer 1

You can implement this functionality with js form events

Answer 2

There is an afterValidate event, the easiest way is to hang it up.

$('#form').on('afterValidate', function (e) {
    $('#loader').show();
    return true;
});