AS3 SWF not loading - actionscript-3

Question

I've generated a class to load and unload SWFs, however, it does not seem to load to swf visually, but it doesn't return any errors either.
Parent code:
//specify the path for the child SWF
var PageURL:URLRequest = new URLRequest("home/home_index.swf");
//include the SWF loading class
import MM_swfloader;
var mainPage:MM_swfloader = new MM_swfloader();
//evoke the load
mainPage.LoadSWF(PageURL);
MM_swfloader class:
package {
import flash.display.Loader;
import flash.display.Sprite;
import flash.events.Event;
import flash.net.URLRequest;
/**
* author: Me
* email: lala#lala.com
**/
public class MM_swfloader extends Sprite {
public var loader:Loader = new Loader();
public function MM_swfloader():void
{
// constructor code
}
public function LoadSWF(val:URLRequest):void{
var loader:Loader = new Loader();
loader.load(val);
addChild(loader);
trace("loaded"); //returns true
}
public function UnLoadSWF():void {
loader.unload();
}
}
}
I don't understand where the loaded SWF is being loaded to. Any ideas?

Answer 1

You need to add the instance of your SWF loading class to the stage in the parent class:
//specify the path for the child SWF
var PageURL:URLRequest = new URLRequest("home/home_index.swf");
//include the SWF loading class
import MM_swfloader;
var mainPage:MM_swfloader = new MM_swfloader();
// add the instance to the stage
this.addChild(mainPage);
//evoke the load
mainPage.LoadSWF(PageURL);
There are also a couple of problems with the code in your loader class which I have fixed below (see the comments for an explanation):
// Poor practice to use the default namespace, stick it in com.lala
package {
import flash.display.Loader;
import flash.display.Sprite;
import flash.events.Event;
import flash.net.URLRequest;
/**
* author: Me
* email: lala#lala.com
**/
public class MM_swfloader extends Sprite {
public var loader:Loader = new Loader();
public function MM_swfloader():void
{
// constructor code
// listen for loader complete on the loader instance
loader.contentLoaderInfo.addEventListener(Event.COMPLETE, loaderCompleteHandler);
// add loader to stage
this.addChild(loader);
}
// Note that by convention loadSWF would be a better name for this method
public function LoadSWF(val:URLRequest):void {
// commented out to avoid creating a new locally-scoped
// loader each time the method is called
//var loader:Loader = new Loader();
loader.load(val);
// commented out to avoid adding child each time
// method is called, added in constructor instead
//addChild(loader);
// loading is asynchronous, this needs to be in a handler
// for the loader.complete event
//trace("loaded"); //returns true
}
// call this unloadSWF
public function UnLoadSWF():void {
loader.unload();
}
// handler for loader.complete event
private function loaderCompleteHandler(event:Event):void {
trace("loaded");
}
}
}

Answer 2

You need to add the loader content to the stage on complete, like so:
import flash.net.URLRequest;
import flash.display.Loader;
import flash.events.Event;
import flash.events.ProgressEvent;
function startLoad()
{
var mLoader:Loader = new Loader();
var mRequest:URLRequest = new URLRequest("someswf.swf");
mLoader.contentLoaderInfo.addEventListener(Event.COMPLETE, onCompleteHandler);
mLoader.contentLoaderInfo.addEventListener(ProgressEvent.PROGRESS, onProgressHandler);
mLoader.load(mRequest);
}
function onCompleteHandler(loadEvent:Event)
{
addChild(loadEvent.currentTarget.content);
}
function onProgressHandler(mProgress:ProgressEvent)
{
var percent:Number = mProgress.bytesLoaded/mProgress.bytesTotal;
trace(percent);
}
startLoad();