where business logic put

Yii 1.1 General Discussion
1

business logic is suggested to put in model, but the model may be very fat. anyone have a idea?

2

Anything that is used just for one model should stay inside model class, if U have anything that’s shared among more models, U can move it to some component

3

this is not related to yii but PHP in general here

http://akrabat.com/php/objects-in-the-model-layer-part-2/