Migrate custom Facebook util library to Yii framework
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I have a facebook app developed in plain PHP, I'm migrating the app to YII framework.

The thing is that I use a class call "utilsFacebook" where I have the object  facebook(of the fb sdk) and all the methods that I need to get data from facebook, getUserId, getUserFriendList, etc.

I don't know how to handle all the operations that I do in utilsFacebook with Yii.

Create a controller with the functions of utilsFacebook is the correct think to do?
Every time that I instance the controller would create a new Facebook object, Should I store that object in a SESSION to get a better performance or is a bad idea?