How to accept "product filter" parameters in Yii 1.1 controller?

Question

Yii

Hello. I got a project on yii 1.1. I have little experience with frameworks.
Situation: in an online store on the product category page there is a filter :
site.ru/wrist-watch/?price_start=888&price_end=&brand=adriatica parameters in the controller (how to collect them for passing to the constructor of the ProductFilter object, because there can be a lot of them)? Thanks in advance.