How to implement form validation in Yii2?

Question

Yii

Good afternoon friends!
Question in the following:
There was an html-template of page with the form, check of input of fields happened by means of JavaScript.
Then I translated the template into Yii2, but I don't understand how to make the same display of messages about erroneous data entry now.
The validate method is used, but it does not display a message that the data entered in the field is incorrect.
Thanks in advance!

Answer 1

Here is a simple example from the official documentation.
https://github.com/ygolikov/yii2/blob/master/docs/...