AS3 Progress Tasks

This library provides an easy way to track progress with the spicelib task framework.

Task framework? That's what the documentation says: "The Task Framework is a general abstraction for asynchronous operations. It allows nesting / grouping of Tasks in TaskGroup instances for concurrent or sequential execution." (Read on here for more information)

This library goes one step further by adding ProgressTask, ProgressTaskGroup and ProgressTaskEvent. They allow you to track the overall progress of your tasks. Besides it provides default progress task implementations for the most common as3 loaders.

Use cases for this library:

• Load files (swf, xml, mp3, image, binary, css) via tasks
• Mix file loading with other tasks (backend calls, setup tasks, etc.)
• Get an overall progress for everything
• Configure loading in different abstraction layers via TaskGroups

Change log

0.3.1 (not yet released)

• [Added] LoaderInfoProgressTask that allows tracking progress of an existing LoaderInfo process, useful for pre-loaders. Contribution by Peter Höche, thanks!
• [Fixed] AbstractLoaderTask and LoaderInfoProgressTask set progress to 1 when bytesLoaded are higher than bytesTotal

0.3.0

• [Added] Support for concurrent progress task groups. Use ConcurrentProgressTaskGroup
• [Added] Interfaces IProgressTask and IProgressTaskGroup added
• [Changed] Former ProgressTaskGroup is now SequentialProgressTaskGroup, old class still exists for backward compatibility

0.2.1

• [Fixed] SWFLoaderTask casted loaded data to Sprite which caused a NullPointer when loading Bitmaps with the ImageLoaderTask
• [Fixed] Calculating progress caused in some browsers errors because totalBytes value was zero

0.2.0

• [Added] Abstract doComplete method in AbstractLoaderTask which is called after the results have been set
• [Changed] Label is not required in constructor of ProgressTasks anymore (now optional)
• [Changed] General clean up (doesn't effect the external API)

0.1.0

• [Added] Progress task
• [Added] Sequential progress task group
• [Added] Progress tasks implementations for CSS, Images, MP3, SWF, XML and Binaries
• [Added] FakeProgressTask for emulating progress

Usage

To get a quick impression how the tasks work, have a look at the example folder in this project or download the demo files.

The following example creates a task group to load two files. By listening for the progress event on the group you get the overall progress.

var taskGroup:ProgressTaskGroup = new ProgressTaskGroup();
taskGroup.addEventListener(ProgressTaskEvent.PROGRESS, handleProgress);
taskGroup.addTask(new SwfLoaderTask("assets/Module.swf"));
taskGroup.addTask(new XmlLoaderTask("assets/config.xml"));
taskGroup.start();

function handleProgress(event:ProgressTaskEvent):void
{
	trace(event.progress);
}

If your tasks vary greatly in size, you can define a weight for each task. The weight values are relative to each other. You can either use percentage numbers, file sizes or your own units. It's up to you:

var taskGroup:ProgressTaskGroup = new ProgressTaskGroup();
taskGroup.addTaskWeighted(swfLoader, 80);
taskGroup.addTaskWeighted(xmlLoader, 20);
taskGroup.start();

To allow the progress tracking in bigger application – over different layers – you can nest as many groups as you want. The ProgressTaskGroup will then provide you always with the total progress:

var xmlGroup:ProgressTaskGroup = new ProgressTaskGroup();
xmlGroup.addTask(xmlLoader1);
xmlGroup.addTask(xmlLoader2);

var rootGroup:ProgressTaskGroup = new ProgressTaskGroup();
rootGroup.addTaskWeighted(swfLoader, 80);
rootGroup.addTaskWeighted(xmlGroup, 20);
rootGroup.start();

Note: You can mix normal task and weighted task assignments. But keep in mind, that the normal tasks always have a weight of 1 internally.

You can also assign non-progress tasks to a ProgressTaskGroup. But the overall progress won't be updated while the assigned tasks are executed.

Roadmap

• Provide ASDocs
• Provide more examples
• Add handling for synchronous security errors