Packagecom.greensock.loading
Classpublic class DataLoader
InheritanceDataLoader Inheritance LoaderItem Inheritance LoaderCore Inheritance flash.events.EventDispatcher
Subclasses BinaryDataLoader, CSSLoader, XMLLoader

Loads generic data which can be text (the default), binary data, or URL-encoded variables.

If the format vars property is "text", the content will be a String containing the text of the loaded file.

If the format vars property is "binary", the content will be a ByteArray object containing the raw binary data. (See also: BinaryDataLoader)

If the format vars property is "variables", the content will be a URLVariables object containing the URL-encoded variables

OPTIONAL VARS PROPERTIES

The following special properties can be passed into the DataLoader constructor via its vars parameter which can be either a generic object or a DataLoaderVars object:

Note: Using a DataLoaderVars 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.

Example AS3 code:
 import com.greensock.loading.*;
 import com.greensock.events.LoaderEvent;
 import flash.utils.ByteArray;
 import flash.net.URLVariables;
 
//create a DataLoader for loading text (the default format)
var loader:DataLoader = new DataLoader("assets/data.txt", {name:"myText", requireWithRoot:this.root, estimatedBytes:900});
//start loading
loader.load();
//Or you could put the DataLoader into a LoaderMax. Create one first...
var queue:LoaderMax = new LoaderMax({name:"mainQueue", onProgress:progressHandler, onComplete:completeHandler, onError:errorHandler});
//append the DataLoader and several other loaders
queue.append( loader );
queue.append( new DataLoader("assets/variables.txt", {name:"myVariables", format:"variables"}) );
queue.append( new DataLoader("assets/image1.png", {name:"myBinary", format:"binary", estimatedBytes:3500}) );
//start loading the LoaderMax queue
queue.load();
function progressHandler(event:LoaderEvent):void {
    trace("progress: " + event.target.progress);
}
function completeHandler(event:LoaderEvent):void {
    var text:String = LoaderMax.getContent("myText");
    var variables:URLVariables = LoaderMax.getContent("myVariables");
    var binary:ByteArray = LoaderMax.getContent("myBinary");
    trace("complete. myText: " + text + ", myVariables.var1: " + variables.var1 + ", myBinary.length: " + binary.length);
}
function errorHandler(event:LoaderEvent):void {
    trace("error occured with " + event.target + ": " + event.text);
}
 

Copyright 2010-2013, GreenSock. All rights reserved. This work is subject to the terms in http://www.greensock.com/terms_of_use.html or for Club GreenSock members, the software agreement that was issued with the membership.

See also

com.greensock.loading.data.DataLoaderVars


Public Properties
 PropertyDefined By
 InheritedauditedSize : Boolean
[read-only] 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
[read-only] Bytes loaded
LoaderCore
 InheritedbytesTotal : uint
[read-only] Total bytes that are to be loaded by the loader.
LoaderCore
 Inheritedcontent : *
[read-only] 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
 InheritedhttpStatus : int
[read-only] The httpStatus code of the loader.
LoaderItem
 InheritedloadTime : Number
[read-only] 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
 Inheritedprogress : Number
[read-only] A value between 0 and 1 indicating the overall progress of the loader.
LoaderCore
 Inheritedrequest : URLRequest
[read-only] The URLRequest associated with the loader.
LoaderItem
 InheritedscriptAccessDenied : Boolean
[read-only] 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
 Inheritedstatus : int
[read-only] Integer code indicating the loader's status; options are LoaderStatus.READY, LoaderStatus.LOADING, LoaderStatus.COMPLETED, 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
Public Methods
 MethodDefined By
  
DataLoader(urlOrRequest:*, vars:Object = null)
Constructor
DataLoader
 Inherited
addEventListener(type:String, listener:Function, useCapture:Boolean = false, priority:int = 0, useWeakReference:Boolean = false):void
[override]
LoaderCore
 Inherited
auditSize():void
[override] 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
 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
 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
[override] 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
Events
 Event Summary Defined By
 InheritedDispatched 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
 InheritedDispatched when the loader completes.LoaderCore
 InheritedDispatched when the loader experiences some type of error, like a SECURITY_ERROR or IO_ERROR.LoaderCore
 InheritedDispatched when the loader fails.LoaderCore
  Dispatched when the loader's httpStatus value changes.DataLoader
 InheritedDispatched when the loader experiences an IO_ERROR while loading or auditing its size.LoaderItem
 InheritedDispatched when the loader starts loading.LoaderCore
 InheritedDispatched each time the bytesLoaded value changes while loading (indicating progress).LoaderCore
  Dispatched when the loader experiences a SECURITY_ERROR while loading or auditing its size.DataLoader
 InheritedDispatched when the loader unloads (which happens when either unload() or dispose(true) is called or if a loader is canceled while in the process of loading).LoaderCore
Constructor Detail
DataLoader()Constructor
public function DataLoader(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 DataLoader("text/data.txt", {name:"data", 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 a DataLoaderVars object:

  • name : String - A name that is used to identify the loader instance. This name can be fed to the LoaderMax.getLoader() or LoaderMax.getContent() methods 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".
  • format : String - Controls whether the downloaded data is received as text ("text"), raw binary data ("binary"), or URL-encoded variables ("variables").
  • 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).
  • noCache : Boolean - If true, a "gsCacheBusterID" 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 LoaderMax.getLoader() or LoaderMax.getContent() by url or 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 is 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 DataLoader as part of its parent SWFLoader's progress, you must set the requireWithRoot property to your swf's root. For example, var loader:DataLoader = new DataLoader("text.txt", {name:"myText", requireWithRoot:this.root});
  • allowMalformedURL : Boolean - Normally, the URL will be parsed and any variables in the query string (like "?name=test&state=il&gender=m") will be placed into a URLVariables object which is added to the URLRequest. This avoids a few bugs in Flash, but if you need to keep the entire URL intact (no parsing into URLVariables), set allowMalformedURL:true. For example, if your URL has duplicate variables in the query string like http://www.greensock.com/?c=S&c=SE&c=SW, it is technically considered a malformed URL and a URLVariables object can't properly contain all the duplicates, so in this case you'd want to set allowMalformedURL to true.
  • 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).
  • 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).
  • onHTTPStatus : Function - A handler function for LoaderEvent.HTTP_STATUS events. Make sure your onHTTPStatus function accepts a single parameter of type LoaderEvent (com.greensock.events.LoaderEvent). You can determine the httpStatus code using the LoaderEvent's target.httpStatus (LoaderItems keep track of their httpStatus when possible, although certain environments prevent Flash from getting httpStatus information).

See also

Event Detail
httpStatus Event
Event Object Type: com.greensock.events.LoaderEvent

Dispatched when the loader's httpStatus value changes.

securityError Event  
Event Object Type: com.greensock.events.LoaderEvent

Dispatched when the loader experiences a SECURITY_ERROR while loading or auditing its size.