When I'm working on an ExtJS project in SA, I can add a "buildUrl" function to a proxy to set custom urls before the proxy connects to the server -

ExtJS Proxy.PNG

I'm starting my first Sencha Touch project in SA, and even though I'm using the same type of proxy, I don't have the option to add arbitrary functions to a proxy, and thus cannot override buildUrl().

SenchaTouch Proxy.PNG

Is there a different way I should be doing this in Sencha Touch? The ST docs still have a buildUrl() function listed for the Ajax proxy, so there should be some way to make it work in SA.