在angularjs中处理jsonp请求的异常

I have the following code which make seperate requests for jsonp data. In the code "doRequestA" works fine and returns a result. The issue I have is I need to catch any errors if they occur. I have tried implementing this in "doRequestB", but only receive the alert error (I have ommitted the callback from doRequestB).I have the following code which make seperate r