Greg Jessup {Blog}

Well after doing a bunch of searching and hacking away, I have managed to come up with a solution!

What I wanted was to set a variable when a change was made in my Flex application. (In my case it meant that a new module was loaded to my dashboard application) This way if a user loaded or deleted a module, the app would save their environment to a Shared Object.
Originally I had it was saving automatically, but user feedback said, only if I want to. This led me to prompting them when the close, but only if something has changed.

Here is how I did it:

First I declare a Bindable variable up at the top of my code (oh also import ExternalInterface)

import flash.external.ExternalInterface;
[Bindable] private var saveRequired:Boolean;

Second in my creationcomplete Event called init(), I add a callback to the ExternalInterface like so:

 private function init():void
		 {
          		if ( ExternalInterface.available ) {       			

          			ExternalInterface.addCallback("checkForUnsavedData",function():String {
          				if (saveRequired ) {
          					unsavedAlert();
          					return UNSAVED_DATA_WARNING;
          				}
						else return "";
					});
          		}
		 }

The following 2 functions are added to handle the Alert when the Javascript kicks off

private function unsavedAlert():void {
           Alert.show("Save?", "Save Alert", Alert.YES|Alert.NO ,this,SaveAlertHandler,null,Alert.YES);
          }

		private function SaveAlertHandler(e:CloseEvent):void {
		  	    if (e.detail == Alert.YES) {
		  	   		 setLSO();
		  	    }
		  	    saveRequired = new Boolean;
		  }

When you determine that a save is required set the variable saveRequired to anything. I wanted it to be a reminder when I went back to debug, so mine look like this…

saveRequired = "Popup on Browser Exit";

Finally….add this code between in your ./html-template/index.template.html

 <script language="JavaScript" type="text/javascript">
<!--
//alert(navigator.appName);
// Give user a chance to save modified data
window.onbeforeunload = function () {

	var warning = getFlexApp('SharedObjectBoard').checkForUnsavedData();
	if (warning != "")
		return warning;
	else
	return;
}

function getFlexApp(appName) {
  if (navigator.appName.indexOf ("Microsoft") !=-1) {
    return window[appName];
	alert(appName);
  }
  else {
    return document[appName];
	}
}
 -->
</script>

Greg FLEX