如何使用查看ng-model中的不同参数再次运行控制器功能

I have a controller that works fine on initial load. It calls user [0] data and everything processes fine. When I change dropdown, I want to call the same function, but I cannot get the entire controller to reload. It starts from the function call and leaves undefined in places where it pulls correct information (linkToken, etc) on initial load. Is there a way I can get it to reload all data from the controller instead of just from the function?I have a controller that works fine on initial