JUI doesn't work

Hello everyone, I’m working with yii2 and I installed it via composer, then I installed jui via composer too sucesfully there was no problem. The problem is when I used a DatePicker in a form, I got a message like this: " PHP Fatal Error – yii\base\ErrorException Class ‘DatePicker’ not found".

I have to say composer creates a folder "yii2-jui" in vendor/yiisoft

in extension.php I got this:

'yiisoft/yii2-jui' => 

  array (

    'name' => 'yiisoft/yii2-jui',

    'version' => '',

    'alias' => 

    array (

      '@yii/jui' => $vendorDir . '/yiisoft/yii2-jui',



in the beggining of DatePicker.php I have this line : namespace yii\jui;

in the form I added: use yii\jui\DatePicker;

also I tried to use the datepicker in this way: widget(\yii\jui\DatePicker::className()

and this: widget(DatePicker::className()

but it still doesn’t work, please somebody help me.Thank you

As far as I know you dont need to install jui,just follow these step and jui datepicker is working.

composer global require "fxp/composer-asset-plugin:1.0.0-beta4"

composer create-project --prefer-dist yiisoft/yii2-app-basic basic