I recently ran into an interesting problem working on putting support for the Windows Azure Access Control Service (ACS) into the Windows Azure iOS Toolkit.

It turns out that once you’ve gone through all of the ACS authentication process, a security token is generated. You need this token to authenticate yourself against ACS-bound web sites. However the ACS web site passes the token to you by calling window.external.Notify()

window.external.Notify("security-token-here");

While window.external.Notify is supported in Internet Explorer on the desktop and also in Windows Phone, it is not supported in iOS. Worse, while the WebView control on the Mac can call your Objective C code from JavaScript, the iOS UIWebView does not support this.

Another mechanism was needed. Here is how I solved it.

One common use for mobile apps is to expose a company’s repertoire of content.

Perhaps your app will present cooking recipes, or First Aid information for folks that hurt themselves hiking far from cell tower coverage.

One challenge often faced in these types of apps is how to keep the content up to date. Of course you could simply ship an update to your app, but your customers may get annoying having to update your app every few weeks.

A better way is to have a means to update the content as it changes. The code I am presenting here is designed to do just that.