Xcode - 排除自定义配置中的文件 - 更好的方法？

I'm trying to come up with a way to make it easy to switch out our "mock" data services and our live ones. Basically, we'll have live servers with real web services, but for whatever reason, a developer may want to load data from static files (file urls). I'm trying to come up with a way to make it eas