How to create Access (view page) role in yii?

Question

How to create access role in yii and where in yii application part ?

I want to create access role in yii application but I have a problem and don't know about where to assign role in yii like I have three department role:

1.admin -: admin have a all access role in our application

2.staff -: staff same of page and access role like to edit or update

3.user -: user have a all access page only viewing in our application

These type of role can set in controller but I can justify where to write all access in yii and how to set access role ,

I try this type code in controller and here I have role in session I cheeked by using this:

admin but this con't access these type page and show error message (anotharization action )

 echo Yii::app()->user->getState('roles'); 
    public function accessRules()
   {
      return array(  
           array('allow', //allow admin user to perform 'index'&'view' actions
                'actions'=>array('index','view'),
                'users'=>array('admin'),
                'roles'=>array('admin'),
                ),
      );
   }

Answer 1

Yii implements a hierarchical RBAC scheme via its CWebApplication ->authManager application component, Take a look at this wiki