Packagecom.greensock.loading
Classpublic class MP3Loader
InheritanceMP3Loader Inheritance LoaderItem Inheritance LoaderCore Inheritance flash.events.EventDispatcher

Loads an MP3 audio file and also provides convenient playback methods and properties like pauseSound(), playSound(), gotoSoundTime(), playProgress, volume, soundPaused, duration, and soundTime. An MP3Loader will dispatch useful events like SOUND_COMPLETE, SOUND_PAUSE, SOUND_PLAY, and PLAY_PROGRESS in addition to the typical loader events, making it easy to hook up your own control interface. It packs a surprising amount of functionality into a very small amount of kb.

OPTIONAL VARS PROPERTIES
The following special properties can be passed into the MP3Loader constructor via its vars parameter which can be either a generic object or an MP3LoaderVars object:

Note: Using a MP3LoaderVars instance instead of a generic object to define your vars is a bit more verbose but provides code hinting and improved debugging because it enforces strict data typing. Use whichever one you prefer.

content data type: flash.media.Sound

NOTE: To avoid garbage collection issues in the Flash player, the Sound object that MP3Loader employs must get recreated internally anytime the MP3Loader is unloaded or its loading is cancelled, so it is best to access the content after the COMPLETE event has been dispatched. Otherwise, if you store a reference to the MP3Loader's content before or during a load and it gets cancelled or unloaded for some reason, the Sound object won't be the one into which the MP3 is eventually loaded.


Example
Example AS3 code:
 import com.greensock.*;
 import com.greensock.loading.*;
 import com.greensock.events.LoaderEvent;
 
 //create a MP3Loader that will begin playing immediately when it loads
 var sound:MP3Loader = new MP3Loader("mp3/audio.mp3", {name:"audio", autoPlay:true, repeat:3, estimatedBytes:9500});
 
 //begin loading
 sound.load();
 
 //add a CLICK listener to a button that causes the sound to toggle its paused state.
 button.addEventListener(MouseEvent.CLICK, toggleSound);
 function toggleSound(event:MouseEvent):void {
     sound.soundPaused = !sound.soundPaused;
 }
 
 //or you could put the MP3Loader into a LoaderMax queue. Create one first...
 var queue:LoaderMax = new LoaderMax({name:"mainQueue", onProgress:progressHandler, onComplete:completeHandler, onError:errorHandler});
 
 //append the MP3Loader and then several other loaders
 queue.append( sound );
 queue.append( new XMLLoader("xml/doc.xml", {name:"xmlDoc", estimatedBytes:425}) );
 queue.append( new ImageLoader("img/photo1.jpg", {name:"photo1", estimatedBytes:3500}) );
 
 //start loading
 queue.load();
 
 function progressHandler(event:LoaderEvent):void {
   trace("progress: " + event.target.progress);
 }
 
 function completeHandler(event:LoaderEvent):void {
   trace(event.target + " is complete!");
 }
 
 function errorHandler(event:LoaderEvent):void {
   trace("error occured with " + event.target + ": " + event.text);
 }
 
Copyright 2010, GreenSock. All rights reserved. This work is subject to the terms in http://www.greensock.com/terms_of_use.html or for corporate Club GreenSock members, the software agreement that was issued with the corporate membership.

See also

com.greensock.loading.data.MP3LoaderVars


Public Properties
 PropertyDefined by
 InheritedauditedSize : Boolean
Indicates whether or not the loader's bytesTotal value has been set by any of the following:
  • Defining an estimatedBytes in the vars object passed to the constructor
  • Calling auditSize() and getting a response (an error is also considered a response)
  • When a LoaderMax instance begins loading, it will automatically force a call to auditSize() for any of its children that don't have an estimatedBytes defined.
LoaderCore
 InheritedautoDispose : Boolean
When autoDispose is true, the loader will be disposed immediately after it completes (it calls the dispose() method internally after dispatching its COMPLETE event).
LoaderCore
 InheritedbytesLoaded : uint
Bytes loaded
LoaderCore
 InheritedbytesTotal : uint
Total bytes that are to be loaded by the loader.
LoaderCore
  channel : SoundChannel
The SoundChannel object that results from the most recent playSound() call (or when autoPlay is true in the constructor's vars parameter).
MP3Loader
 Inheritedcontent : *
The content that was loaded by the loader which varies by the type of loader:
  • ImageLoader - A com.greensock.loading.display.ContentDisplay (a Sprite) which contains the ImageLoader's rawContent (a flash.display.Bitmap unless script access was denied in which case rawContent will be a flash.display.Loader to avoid security errors).
LoaderCore
  duration : Number
[read-only] The duration (in seconds) of the sound.
MP3Loader
 InheritedhttpStatus : int
The httpStatus code of the loader.
LoaderItem
  initThreshold : uint
The minimum number of bytesLoaded to wait for before the LoaderEvent.INIT event is dispatched - the higher the number the more accurate the duration estimate will be when the INIT event is dispatched (the default value is 102400 which is 100k).
MP3Loader
 InheritedloadTime : Number
The number of seconds that elapsed between when the loader began and when it either completed, failed, or was canceled.
LoaderCore
 Inheritedname : String
A name that you use to identify the loader instance.
LoaderCore
 Inheritedpaused : Boolean
If a loader is paused, its progress will halt and any LoaderMax instances to which it belongs will either skip over it or stop when its position is reached in the queue (depending on whether or not the LoaderMax's skipPaused property is true).
LoaderCore
  playProgress : Number
A value between 0 and 1 describing the playback progress where 0 means the virtual playhead is at the very beginning of the sound, 0.5 means it is at the halfway point and 1 means it is at the end of the sound.
MP3Loader
 Inheritedprogress : Number
A value between 0 and 1 indicating the overall progress of the loader.
LoaderCore
 Inheritedrequest : URLRequest
The URLRequest associated with the loader.
LoaderItem
 InheritedscriptAccessDenied : Boolean
If the loaded content is denied script access (because of security sandbox restrictions, a missing crossdomain.xml file, etc.), scriptAccessDenied will be set to true.
LoaderItem
  soundPaused : Boolean
The playback status of the sound: true if the sound's playback is paused, false if it isn't.
MP3Loader
  soundTime : Number
The time (in seconds) at which the virtual playhead is positioned on the sound.
MP3Loader
 Inheritedstatus : int
Integer code indicating the loader's status; options are LoaderStatus.READY, LoaderStatus.LOADING, LoaderStatus.COMPLETE, LoaderStatus.PAUSED, and LoaderStatus.DISPOSED.
LoaderCore
 Inheritedurl : String
The url from which the loader should get its content.
LoaderItem
 Inheritedvars : Object
An object containing optional configuration details, typically passed through a constructor parameter.
LoaderCore
  volume : Number
The volume of the sound (a value between 0 and 1).
MP3Loader
Public Methods
 MethodDefined by
  
MP3Loader(urlOrRequest:*, vars:Object = null)
Constructor.
MP3Loader
  
addEventListener(type:String, listener:Function, useCapture:Boolean = false, priority:int = 0, useWeakReference:Boolean = false):void
MP3Loader
 Inherited
auditSize():void
Attempts loading just enough of the content to accurately determine the bytesTotal in order to improve the accuracy of the progress property.
LoaderItem
 Inherited
cancel():void
If the loader is currently loading (status is LoaderStatus.LOADING), it will be canceled immediately and its status will change to LoaderStatus.READY.
LoaderCore
 Inherited
dispose(flushContent:Boolean = false):void
Disposes of the loader and releases it internally for garbage collection.
LoaderCore
  
gotoSoundTime(time:Number, forcePlay:Boolean = false):void
Attempts to jump to a certain time in the sound.
MP3Loader
 Inherited
load(flushContent:Boolean = false):void
Loads the loader's content, optionally flushing any previously loaded content first.
LoaderCore
 Inherited
pause():void
Pauses the loader immediately.
LoaderCore
  
pauseSound(event:Event = null):void
Pauses playback of the sound.
MP3Loader
  
playSound(event:Event = null):SoundChannel
Plays the sound.
MP3Loader
 Inherited
prioritize(loadNow:Boolean = true):void
Immediately prioritizes the loader inside any LoaderMax instances that contain it, forcing it to the top position in their queue and optionally calls load() immediately as well.
LoaderCore
 Inherited
resume():void
Unpauses the loader and resumes loading immediately.
LoaderCore
 Inherited
toString():String
Returns information about the loader, like its type, its name, and its url (if it has one).
LoaderCore
 Inherited
unload():void
Removes any content that was loaded and sets bytesLoaded back to zero.
LoaderCore
Protected Methods
 MethodDefined by
 Inherited
LoaderItem
Events
 EventSummaryDefined by
 Inherited Dispatched when the loader is canceled while loading which can occur either because of a failure or when a sibling loader is prioritized in a LoaderMax queue.LoaderCore
 Inherited Dispatched when the loader completes.LoaderCore
 Inherited Dispatched when the loader experiences some type of error, like a SECURITY_ERROR or IO_ERROR.LoaderCore
 Inherited Dispatched when the loader fails.LoaderCore
 Inherited Dispatched when the loader experiences an IO_ERROR while loading or auditing its size.LoaderItem
 Inherited Dispatched when the loader starts loading.LoaderCore
 Inherited Dispatched each time the bytesLoaded value changes while loading (indicating progress).LoaderCore
Public Constants
 ConstantDefined by
  PLAY_PROGRESS : String = "playProgress"
[static] Event type constant for when the playback progresses (only dispatched when the sound is playing).
MP3Loader
  SOUND_COMPLETE : String = "soundComplete"
[static] Event type constant for when the sound completes.
MP3Loader
  SOUND_PAUSE : String = "soundPause"
[static] Event type constant for when the sound is paused.
MP3Loader
  SOUND_PLAY : String = "soundPlay"
[static] Event type constant for when the sound begins or resumes playing.
MP3Loader
Property detail
channelproperty
public var channel:SoundChannel

The SoundChannel object that results from the most recent playSound() call (or when autoPlay is true in the constructor's vars parameter). Typically there isn't much reason to use this directly. Instead, use the MP3Loader's controls like playSound(), pauseSound(), gotoSoundTime(), playProgress, duration, soundTime, etc.

durationproperty 
duration:Number  [read-only]

The duration (in seconds) of the sound. This value cannot be determined with 100% accuracy until the file has completely loaded, but it is estimated with more and more accuracy as the file loads.

Implementation
    public function get duration():Number
initThresholdproperty 
public var initThreshold:uint

The minimum number of bytesLoaded to wait for before the LoaderEvent.INIT event is dispatched - the higher the number the more accurate the duration estimate will be when the INIT event is dispatched (the default value is 102400 which is 100k). The MP3's duration cannot be determined with 100% accuracy until it has completely loaded, but it is estimated with more and more accuracy as the file loads.

playProgressproperty 
playProgress:Number  [read-write]

A value between 0 and 1 describing the playback progress where 0 means the virtual playhead is at the very beginning of the sound, 0.5 means it is at the halfway point and 1 means it is at the end of the sound.

Implementation
    public function get playProgress():Number
    public function set playProgress(value:Number):void
soundPausedproperty 
soundPaused:Boolean  [read-write]

The playback status of the sound: true if the sound's playback is paused, false if it isn't.

Implementation
    public function get soundPaused():Boolean
    public function set soundPaused(value:Boolean):void
soundTimeproperty 
soundTime:Number  [read-write]

The time (in seconds) at which the virtual playhead is positioned on the sound. For example, if the virtual playhead is currently at the 3-second position (3 seconds from the beginning), this value would be 3.

Implementation
    public function get soundTime():Number
    public function set soundTime(value:Number):void
volumeproperty 
volume:Number  [read-write]

The volume of the sound (a value between 0 and 1).

Implementation
    public function get volume():Number
    public function set volume(value:Number):void
Constructor detail
MP3Loader()constructor
public function MP3Loader(urlOrRequest:*, vars:Object = null)

Constructor.

Parameters
urlOrRequest:* — The url (String) or URLRequest from which the loader should get its content
 
vars:Object (default = null) — An object containing optional configuration details. For example: new MP3Loader("mp3/audio.mp3", {name:"audio", autoPlay:true, onComplete:completeHandler, onProgress:progressHandler}).

The following special properties can be passed into the constructor via the vars parameter which can be either a generic object or an MP3LoaderVars object:
  • name : String - A name that is used to identify the MP3Loader instance. This name can be fed to the find() method or traced at any time. Each loader's name should be unique. If you don't define one, a unique name will be created automatically, like "loader21".
  • autoPlay : Boolean - By default the MP3 will begin playing immediately when enough of the file has buffered, but to prevent it from autoPlaying, set autoPlay to false.
  • repeat : int - Number of times that the mp3 should repeat. To repeat indefinitely, use -1. Default is 0.
  • volume : Number - A value between 0 and 1 indicating the volume at which the sound should play (default is 1).
  • initThreshold : uint - The minimum number of bytesLoaded to wait for before the LoaderEvent.INIT event is dispatched - the higher the number the more accurate the duration estimate will be when the INIT event is dispatched (the default value is 102400 which is 100k). The MP3's duration cannot be determined with 100% accuracy until it has completely loaded, but it is estimated with more and more accuracy as the file loads..
  • alternateURL : String - If you define an alternateURL, the loader will initially try to load from its original url and if it fails, it will automatically (and permanently) change the loader's url to the alternateURL and try again. Think of it as a fallback or backup url. It is perfectly acceptable to use the same alternateURL for multiple loaders (maybe a default image for various ImageLoaders for example).
  • context : SoundLoaderContext - To control things like the buffer time and whether or not a policy file is checked, define a SoundLoaderContext object. The default context is null. See Adobe's SoundLoaderContext documentation for details.
  • noCache : Boolean - If noCache is true, a "cacheBusterID" parameter will be appended to the url with a random set of numbers to prevent caching (don't worry, this info is ignored when you getLoader() or getContent() by url and when you're running locally)
  • estimatedBytes : uint - Initially, the loader's bytesTotal is set to the estimatedBytes value (or LoaderMax.defaultEstimatedBytes if one isn't defined). Then, when the loader begins loading and it can accurately determine the bytesTotal, it will do so. Setting estimatedBytes is optional, but the more accurate the value, the more accurate your loaders' overall progress will be initially. If the loader will be inserted into a LoaderMax instance (for queue management), its auditSize feature can attempt to automatically determine the bytesTotal at runtime (there is a slight performance penalty for this, however - see LoaderMax's documentation for details).
  • requireWithRoot : DisplayObject - LoaderMax supports subloading, where an object can be factored into a parent's loading progress. If you want LoaderMax to require this MP3Loader as part of its parent SWFLoader's progress, you must set the requireWithRoot property to your swf's root. For example, var loader:MP3Loader = new MP3Loader("audio.mp3", {name:"audio", requireWithRoot:this.root});
  • autoDispose : Boolean - When autoDispose is true, the loader will be disposed immediately after it completes (it calls the dispose() method internally after dispatching its COMPLETE event). This will remove any listeners that were defined in the vars object (like onComplete, onProgress, onError, onInit). Once a loader is disposed, it can no longer be found with LoaderMax.getLoader() or LoaderMax.getContent() - it is essentially destroyed but its content is not unloaded (you must call unload() or dispose(true) to unload its content). The default autoDispose value is false.

    ----EVENT HANDLER SHORTCUTS----
  • onOpen : Function - A handler function for LoaderEvent.OPEN events which are dispatched when the loader begins loading. Make sure your onOpen function accepts a single parameter of type LoaderEvent (com.greensock.events.LoaderEvent).
  • onInit : Function - A handler function for Event.INIT events which will be dispatched when the bytesLoaded exceeds the initThreshold (100k by default) and the MP3 has streamed enough of its content to identify the ID3 meta data. Make sure your onInit function accepts a single parameter of type LoaderEvent (com.greensock.events.LoaderEvent).
  • onProgress : Function - A handler function for LoaderEvent.PROGRESS events which are dispatched whenever the bytesLoaded changes. Make sure your onProgress function accepts a single parameter of type LoaderEvent (com.greensock.events.LoaderEvent). You can use the LoaderEvent's target.progress to get the loader's progress value or use its target.bytesLoaded and target.bytesTotal.
  • onComplete : Function - A handler function for LoaderEvent.COMPLETE events which are dispatched when the loader has finished loading successfully. Make sure your onComplete function accepts a single parameter of type LoaderEvent (com.greensock.events.LoaderEvent).
  • onCancel : Function - A handler function for LoaderEvent.CANCEL events which are dispatched when loading is aborted due to either a failure or because another loader was prioritized or cancel() was manually called. Make sure your onCancel function accepts a single parameter of type LoaderEvent (com.greensock.events.LoaderEvent).
  • onError : Function - A handler function for LoaderEvent.ERROR events which are dispatched whenever the loader experiences an error (typically an IO_ERROR or SECURITY_ERROR). An error doesn't necessarily mean the loader failed, however - to listen for when a loader fails, use the onFail special property. Make sure your onError function accepts a single parameter of type LoaderEvent (com.greensock.events.LoaderEvent).
  • onFail : Function - A handler function for LoaderEvent.FAIL events which are dispatched whenever the loader fails and its status changes to LoaderStatus.FAILED. Make sure your onFail function accepts a single parameter of type LoaderEvent (com.greensock.events.LoaderEvent).
  • onIOError : Function - A handler function for LoaderEvent.IO_ERROR events which will also call the onError handler, so you can use that as more of a catch-all whereas onIOError is specifically for LoaderEvent.IO_ERROR events. Make sure your onIOError function accepts a single parameter of type LoaderEvent (com.greensock.events.LoaderEvent).

See also

Method detail
addEventListener()method
public override function addEventListener(type:String, listener:Function, useCapture:Boolean = false, priority:int = 0, useWeakReference:Boolean = false):void

Parameters
type:String
 
listener:Function
 
useCapture:Boolean (default = false)
 
priority:int (default = 0)
 
useWeakReference:Boolean (default = false)
gotoSoundTime()method 
public function gotoSoundTime(time:Number, forcePlay:Boolean = false):void

Attempts to jump to a certain time in the sound. If the sound hasn't downloaded enough to get to the new time, it will get as close as possible. For example, to jump to exactly 3-seconds into the sound and play from there:

loader.gotoSoundTime(3, true);

Parameters
time:Number — The time (in seconds, offset from the very beginning) at which to place the virtual playhead in the sound.
 
forcePlay:Boolean (default = false) — If true, the sound will resume playback immediately after seeking to the new position.

See also

pauseSound()method 
public function pauseSound(event:Event = null):void

Pauses playback of the sound.

Parameters
event:Event (default = null) — An optional Event which simply makes it easier to use the method as a handler for mouse clicks or other events.

See also

playSound()method 
public function playSound(event:Event = null):SoundChannel

Plays the sound.

Parameters
event:Event (default = null) — An optional Event which simply makes it easier to use the method as a handler for mouse clicks or other events.

Returns
SoundChannel — The SoundChannel object created by the play()

See also

Constant detail
PLAY_PROGRESSconstant
public static const PLAY_PROGRESS:String = "playProgress"

Event type constant for when the playback progresses (only dispatched when the sound is playing).

SOUND_COMPLETEconstant 
public static const SOUND_COMPLETE:String = "soundComplete"

Event type constant for when the sound completes.

SOUND_PAUSEconstant 
public static const SOUND_PAUSE:String = "soundPause"

Event type constant for when the sound is paused.

SOUND_PLAYconstant 
public static const SOUND_PLAY:String = "soundPlay"

Event type constant for when the sound begins or resumes playing.