ExtJS-WebWorker

ExtJS-WebWorker is an extension to handle and use the HTML5 WebWorker with ExtJS and Sencha Touch.

It has two classes: Ext.ux.WebWorker and Ext.ux.WebWorkerManager
The first one is a wrapper for standard HTML5 WebWorker and it provides a lot of interesting and easy-to-use features. The second one is a singleton to register different Ext.ux.WebWorker and it provides functions to work with every registered webworker at the same time.

Install via Bower

First of all, install Bower.

Then install Ext.ux.WebWorker:

$ bower install ext.ux.webworker

Now, you got the extension at the following path: YOUR_PROJECT_PATH/bower_components/ext.ux.webworker/

It contains WebWorker.js and WebWorkerManager.js files and a minified version WebWorker.min.js and WebWorkerManager.min.js.

Let's setup the Ext.Loader to require the right file:

Ext.Loader.setConfig ({
	enabled: true ,
	paths: {
		'Ext.ux.WebWorker': 'bower_components/ext.ux.webworker/WebWorker.js' ,
		// or the minified one: 'Ext.ux.WebWorker': 'bower_components/ext.ux.webworker/WebWorker.min.js'
		'Ext.ux.WebWorkerManager': 'bower_components/ext.ux.webworker/WebWorkerManager.js' ,
		// or the minified one: 'Ext.ux.WebWorkerManager': 'bower_components/ext.ux.webworker/WebWorkerManager.min.js'
	}
});

Ext.require (['Ext.ux.WebWorker', 'Ext.ux.WebWorkerManager']);

Usage

Load Ext.ux.WebWorker and Ext.ux.WebWorkerManager via Ext.require:

Ext.Loader.setConfig ({
	enabled: true
});

Ext.require (['Ext.ux.WebWorker', 'Ext.ux.WebWorkerManager']);

Now, you are ready to use them in your code as follows:

// There are two ways to create a worker: from a file or inline.

// Build a worker from a different file
var ww = Ext.create ('Ext.ux.WebWorker', {
	file: 'myWorker.js'
});

// Build a worker inline
var ww = Ext.create ('Ext.ux.WebWorker', {
	blob: 'onmessage = function (e) {postMessage ("A message from worker: + " e.data);}'
});

// Using Ext.ux.WebWebWorkerManager
Ext.ux.WebWorkerManager.register (ww);

Communications supported

Pure text communication

The communication is text-only, without objects or any other kind of data.

var webworker = Ext.create ('Ext.ux.WebWorker', {
	file: 'myWorker.js' ,
	listeners: {
		message: function (ww, message) {
			console.log ('A new message is arrived: ' + message);
		} ,
		error: function (ww, error) {
			Ext.Error.raise (error);
		}
	}
});

// myWorker.js
postMessage ('this is the message!');

Pure event-driven communication

The communication is event-driven: an event and a String or Object are sent and the webworker handles different events.

var webworker = Ext.create ('Ext.ux.WebWorker', {
	file: 'myWorker.js' ,
	listeners: {
		start: function (ww, message) {
			console.log (message);
			ww.send ('parse', 'a string to parse');
		} ,
		verify: function (ww, message) {
			console.log (message);
			ww.send ('verify equation', {
				equation: 'x+y-z=10' ,
				x: 10 ,
				y: 5 ,
				z: 5
			});
		}
	}
});

// A 'terminate' event is sent from the worker (myWorker.js)
// 'data' has 'log' and 'msg' fields
webworker.on ('terminate', function (data) {
	console.log ('Log: ' + data.log);
	console.log ('Message: ' + data.msg);
});

webworker.send ({
	event: 'start'
});

// myWorker.js
onmessage = function (message) {
	switch (message.event) {
		case 'start':
			postMessage ({
				event: 'start' ,
				data: 'WebWorker started!'
			});
			break;
		case 'parse':
			postMessage ({
				event: 'verify' ,
				data: 'String parsed! Next!'
			});
			break;
		case 'verify equation':
			postMessage ({
				event: 'terminate' ,
				data: {
					log: message.data.x + '+' + message.data.y + '-' + message.data.z + '=10' ,
					msg: 'Equation verified! Terminate!'
				}
			});
			close ();
			break;
	}
}

Mixed communication

The communication is mixed: it handles text-only and event-driven communication.

var webworker = Ext.create ('Ext.ux.WebWorker', {
	file: 'myWorker.js' ,
	listeners: {
		message: function (ww, message) {
			console.log ('Text-only message arrived is: ' + message);
		}
	}
});

webworker.send ({
	event: 'echo' ,
	data: 'Send me a pure-text message plz!'
});

// myWorker.js
onmessage = function (message) {
	switch (message.event) {
		case 'echo':
			postMessage (message.data);
			break;
	}
}

Ext.ux.WebWorkerManager features

Here's an example of the manager:

var ww1 = Ext.create ('Ext.ux.WebWorker', {
	file: 'myWorker.js'
});

Ext.ux.WebWorkerManager.register (ww1);

var blob = [
	'onmessage = function (msg) {' ,
	'	if (msg.event === "system shutdown") {' ,
	'		var res = {' ,
	'			event: "stop" ,' ,
	'			data: "Computation of worker 2 terminates correctly in 15h13m20s."' ,
	'		};' ,
	'		postMessage (res);' ,
	'	}' ,
	'}'
].join ('');

var ww2 = Ext.create ('Ext.ux.WebWorker', {
	blob: blob
});

Ext.ux.WebWorkerManager.register (ww2);

var ww3 = Ext.create ('Ext.ux.WebWorker', {
	file: 'otherWorker.js'
});

Ext.ux.WebWorkerManager.register (ww3);

Ext.ux.WebWorkerManager.listen ('stop', function (ww, data) {
	Ext.Msg.show ({
		title: 'Worker stopped' ,
		msg: 'Log of the computation: ' + data ,
		icon: Ext.Msg.INFO ,
		buttons: Ext.Msg.OK
	});
});

// This will be handled by everyone
Ext.ux.WebWorkerManager.broadcast ('system shutdown', 'BROADCAST: the system will shutdown in few minutes.');

Ext.ux.WebWorkerManager.stopAll ();

Ext.ux.WebWorkerManager.unregister (ww1);
Ext.ux.WebWorkerManager.unregister (ww2);
Ext.ux.WebWorkerManager.unregister (ww3);

Run the demo

Go to http://localhost/ExtJS-WebWorker/demo and play it!

Documentation

You can build the documentation (like ExtJS Docs) with jsduck:

$ jsduck ux --output /var/www/docs

It will make the documentation into docs dir and it will be visible at: http://localhost/docs

License

The MIT License (MIT)

Copyright (c) 2013 Vincenzo Ferrari wilk3ert@gmail.com

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.