validation

Yii 1.1 General Discussion
1

can we perform clientside validation as well as serverside validation simultaneously

2

Yes you can. There is support for that in CActiveForm:




$form = $this->beginWidget('CActiveForm', array(

    'id'=>'user-form',

    'enableAjaxValidation'=>false,

    'enableClientValidation'=>true,

    'focus'=>array($model,'firstName')

));

but you can use whatever clientside validation framework you want. server side just needs to receive some posted data and what happens with this data prior to send - does not matter.

Using clientside validation (not ajax validation) can reduce server usage as there is less invalid requests.