Not all errors in ActionScript 3 happen when you call a function. Some errors can occur sometime after the call. A common example of this is loading content from the web like XML or other content. Here is a sample of how to catch these types of errors
var myLoader:URLLoader = new URLLoader();
myLoader.addEventListener(IOErrorEvent.IO_ERROR, catchIOError); function catchIOError(event:IOErrorEvent){ trace("Error caught: "+event.type); }
myLoader.load(new URLRequest("Invalid XML URL")); trace("Error, continuing...");
This will output: Error, continuing... Error caught: ioError