Are Yii sessions and PHP sessions cross-compatible?

Question

In Yii, while looking at the source code for CWebUser::logout, I've noticed that they use Yii::app()->getSession()->destroy() instead of the usual PHP session_destroy.

Doing a bit of research I saw that Yii has a class called CHttpSession with its own methods to store data.

This got me thinking - are they cross-compatible? Is CHttpSession just a nice wrapper? Or is it an all or nothing process?

In my custom code, I've been using $_SESSION to do all of my session-related stuff. While in things generated by Yii, I assume that it uses CHttpSession. Is it a problem to use both and mix them up?

I am now in the process of moving my session handling to AWS DynamoDB (https://github.com/aws/aws-sdk-php/blob/master/docs/feature-dynamodb-session-handler.rst), and before I add this additional layer, I want to make sure everything is compatible.

Answer 1

CHttpSession is a nifty OO wrapper for php sessions. The underlying implementation uses php's session methods. Here's a snippet of part of the code for CHttpSession::open():

public function open()
{
    if($this->getUseCustomStorage())
        @session_set_save_handler( array($this,'openSession'),array($this,'closeSession'),array($this,'readSession'),array($this,'writeSession'),array($this,'destroySession'),array($this,'gcSession'));

    @session_start();

For Yii convention, always use CHttpSession instead of $_SESSION.

Answer 2

You can use Database based session to recover that. Its really simple. Just put

'session' => array( 
                'class'=>'CDbHttpSession', 
                 'connectionID' => 'db' 
),

on config/main.php components