Abstract Class yii\web\MultiFieldSession

A callback that will be called during session data reading. The signature of the callback should be as follows:

function ($fields)

where $fields is the storage field set for read session and $session is this session instance. If callback returns an array, it will be merged into the session data.

For example:

function ($fields) {
    return [
        'expireDate' => Yii::$app->formatter->asDate($fields['expire']),
    ];
}

Whether to use custom storage.

A callback that will be called during session data writing. The signature of the callback should be as follows:

function ($session)

where $session is this session instance, this variable can be used to retrieve session data. Callback should return the actual fields set, which should be saved into the session storage.

For example:

function ($session) {
    return [
        'user_id' => Yii::$app->user->id,
        'ip' => $_SERVER['REMOTE_ADDR'],
        'is_trusted' => $session->get('is_trusted', false),
    ];
}