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    scaleApp is a JavaScript framework for scalable One-Page-Applications
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    What is scaleApp?

    scaleApp is a tiny JavaScript framework for scalable and maintainable One-Page-Applications / Single-Page-Applications. The framework allows you to easily create complex web applications.

    Build Status Dependency Status NPM version Coverage Status

    You can dynamically start and stop/destroy modules that acts as small parts of your whole application.

    Architecture overview

    scaleApp is based on a decoupled, event-driven architecture that is inspired by the talk of Nicholas C. Zakas - "Scalable JavaScript Application Architecture" (Slides). There also is a little Article that describes the basic ideas.

    scaleApp architecture

    Module

    A module is a completely independent part of your application. It has absolutely no reference to another piece of the app. The only thing the module knows is your sandbox. The sandbox is used to communicate with other parts of the application.

    Sandbox

    The main purpose of the sandbox is to use the facade pattern. In that way you can hide the features provided by the core and only show a well defined custom static long term API to your modules. This is actually one of the most important concept for creating mainainable apps. Change plugins, implementations etc. but keep your API stable for your modules. For each module a separate sandbox will be created.

    Core

    The core is responsible for starting and stopping your modules. It also handles the messages by using the Publish/Subscribe (Mediator) pattern

    Plugin

    Plugins can extend the core or the sandbox with additional features. For example you could extend the core with basic functionalities (like DOM manipulation) or just aliases the features of a base library (e.g. jQuery).

    Features

    • loose coupling of modules
    • small (about 300 sloc / 8,7k min / 3.3k gz)
    • no dependencies
    • modules can be tested separately
    • replacing any module without affecting other modules
    • extendable with plugins
    • browser and Node.js support
    • flow control
    • AMD & CommonJS support
    • framework-agnostic

    Extendable

    scaleApp itself is very small but it can be extended with plugins. There already are some plugins available:

    • mvc - simple MVC
    • i18n - multi language UIs
    • permission - take care of method access
    • state - Finite State Machine
    • submodule - cascade modules
    • dom - DOM manipulation
    • strophe - XMPP communication
    • modulestate - event emitter for init and destroy
    • util - helper methods like mixin, uniqueId etc.
    • ls - list modules, instances & plugins

    You can easily define your own plugin (see plugin section).

    Download

    Latest stable 0.4.x version

    or use the CDN:

    <script src="//cdnjs.cloudflare.com/ajax/libs/scaleapp/0.4.4/scaleapp.min.js" ></script>
    

    Old stable 0.3.x version

    Note

    There are some API changes in version 0.4.x (see Changelog). Docs for v0.3.9 can be found within the tar/zip file.

    Unstable version

    git clone git://github.com/flosse/scaleApp.git
    

    Quick Start

    Link scaleApp.min.js in your HTML file:

    <script src="scaleApp.min.js"></script>
    

    or use the CDN:

    <script src="//cdnjs.cloudflare.com/ajax/libs/scaleapp/0.4.4/scaleapp.min.js" ></script>
    

    If you're going to use it with node:

    npm install scaleapp --save
    
    var sa = require("scaleapp");
    

    or use bower:

    bower install scaleapp
    

    Create your own Sandbox

    First of all create your own sandbox. By doing that you're able to guarantee a stable maintainable API for your modules.

    var MySandbox = function(core, instanceId, options, moduleId) {
    
      // define your API
      this.myFooProperty = "bar";
    
      // e.g. provide the Mediator methods 'on', 'emit', etc.
      core._mediator.installTo(this);
    
      // ... or define your custom communication methods
      this.myEmit = function(channel, data){
        core.emit(channel + '/' + instanceId, data);
      };
    
      // maybe you'd like to expose the instance ID
      this.id = instanceId;
    
      return this;
    };
    
    // ... and of course you can define shared methods etc.
    MySandbox.prototype.foo = function() { /*...*/ };
    

    Create a core

    Now create a new core instance with your sandbox:

    var core = new scaleApp.Core(MySandbox);
    

    Register modules

    core.register( "myModuleId", function( sandbox ){
      return {
        init:    function(){ /*...*/ },
        destroy: function(){ /*...*/ }
      };
    });
    

    As you can see the module is a function that takes the sandbox as a parameter and returns an object that has two functions init and destroy (the latter is optional). Of course your module can be any usual class with those two functions.

    var MyGreatModule = function(sandbox){
      return {
        init:    function(){ alert("Hello world!"); }
        destroy: function(){ alert("Bye bye!");     }
      };
    };
    
    core.register("myGreatModule", MyGreatModule);
    

    The init function is called by the framework when the module is supposed to start. The destroy function is called when the module has to shut down.

    Asynchronous initialization

    You can also init or destroy you module in a asynchronous way:

    var MyAsyncModule = function(sandbox){
      return {
        init: function(options, done){
          doSomethingAsync(function(err){
            // ...
            done(err);
          });
        },
        destroy: function(done){
          doSomethingElseAsync(done);
        }
      };
    };
    
    core.register("myGreatModule", MyGreatModule);
    core.start("myGreatModule", { done:function(){
      alert("now the initialization is done");
    }});
    

    Start modules

    After your modules are registered, start your modules:

    core
      .start( "myModuleId" )
      .start( "anOtherModule", function(err){
        // 'anOtherModule' is running now
      });
    

    Start options

    You may also want to start several instances of a module:

    core.start( "myModuleId", {instanceId: "myInstanceId" } );
    core.start( "myModuleId", {instanceId: "anOtherInstanceId" });
    

    All you attach to options is accessible within your module:

    core.register( "mod", function(sandbox){
      return {
        init: function(opt){
          (opt.myProperty === "myValue")  // true
        },
        destroy: function(){ /*...*/ }
      };
    });
    
    core.start("mod", {
      instanceId: "test",
      options: { myProperty: "myValue" }
    });
    

    If all your modules just needs to be instanciated once, you can simply starting them all:

    core.start();
    

    To start some special modules at once you can pass an array with the module names:

    core.start(["moduleA","moduleB"]);
    

    You can also pass a callback function:

    core.start(function(){
      // do something when all modules were initialized
    });
    

    Moreover you can use a separate sandbox for each instance:

    var MySandbox = function(){/*...*/};
    core.start("module", { sandbox: MySandbox });
    

    Stopping

    It's obvious:

    core.stop("moduleB");
    core.stop(); // stops all running instances
    

    Publish/Subscribe

    If the module needs to communicate with others, you can use the emit and on methods.

    emit

    The emit function takes three parameters whereas the last one is optional:

    • topic : the channel name you want to emit to
    • data : the data itself
    • cb : callback method

    The emit function is accessible through the sandbox (as long as you exposed the Mediator methods of course):

    sandbox.emit( "myEventTopic", myData );
    

    on

    A message handler could look like this:

    var messageHandler = function( data, topic ){
      switch( topic ){
        case "somethingHappend":
          sandbox.emit( "myEventTopic", processData(data) );
          break;
        case "aNiceTopic":
          justProcess( data );
          break;
      }
    };
    

    ... and it can listen to one or more channels:

    sub1 = sandbox.on( "somthingHappend", messageHandler );
    sub2 = sandbox.on( "aNiceTopic", messageHandler );
    

    Or just do it at once:

    sandbox.on({
      topicA: cbA,
      topicB: cbB,
      topicC: cbC
    });
    

    You can also subscribe to several channels at once:

    sandbox.on(["a", "b"], cb);
    

    If you prefer a shorter method name you can use the alias on.

    attache and detache

    A subscription can be detached and attached again:

    sub.detach(); // don't listen any more
    sub.attach(); // receive upcoming messages
    

    Unsubscribe

    You can unsubscribe a function from a channel

    sandbox.off("a-channel", callback);
    

    And you can remove a callback function from all channels

    sandbox.off(callback);
    

    Or remove all subscriptions from a channel:

    sandbox.off("channelName");
    

    Flow control

    Series

    var task1 = function(next){
      setTimeout(function(){
        console.log("task1");
        next(null, "one");
      },0);
    };
    
    var task2 = function(next){
      console.log("task2");
      next(null, "two");
    };
    
    scaleApp.util.runSeries([task1, task2], function(err, result){
      // result is ["one", "two"]
    });
    
    // console output is:
    // "task1"
    // "task2"
    

    Parallel

    var task1 = function(next){
      setTimeout(function(){
        console.log("task1");
        next(null, "a");
      },0);
    };
    
    var task2 = function(next){
      console.log("task2");
      next(null, "b");
    };
    
    scaleApp.util.runParallel([task1, task2],function(err,result){
      // result is ["a", "b"]
    });
    
    // console output is:
    // "task2"
    // "task1"
    

    There is also a little helper tool to run the same async task again and again in parallel for different values:

    var vals = ["a","b", "c"];
    var worker = function(val, next){
      console.log(val);
      doSomeAsyncValueProcessing(val,function(err,result){
        next(err, result);
      });
    };
    
    scaleApp.util.doForAll(args, worker, function(err, res){
      // fini
    });
    

    Waterfall

    var task1 = function(next){
      setTimeout(function(){
        next(null, "one", "two");
      },0);
    };
    
    var task2 = function(res1, res2, next){
      // res1 is "one"
      // res2 is "two"
      next(null, "yeah!");
    };
    
    scaleApp.util.runWaterfall([task1, task2], function(err, result){
      // result is "yeah!"
    });
    

    Plugins

    There are some plugins available within the plugins folder. For more information look at the plugin README.

    Register plugins

    A single plugin can be registered with it option object in that way:

    core.use(plugin,options);
    

    If you want to register multiple plugins at once:

    core.use([
      plugin1,
      plugin2,
      { plugin: plugin3, options: options3 }
    ]);
    

    Write your own plugin

    It's easy:

    core.use(function(core){
      core.helloWorld = function(){ alert("helloWorld"); };
    };
    

    Here a more complex example:

    core.use(function(core, options, done){
    
      // extend the core
      core.myCoreFunction = function(){ alert("Hello core plugin") };
      core.myBoringProperty = "boring";
    
      // extend the sandbox class
      core.Sandbox.prototype.myMethod = function(){/*...*/};
    
      // define a method that gets called when a module starts
      var onModuleInit = function(instanceSandbox, options, done){
    
        // e.g. define sandbox methods dynamically
        if (options.mySwitch){
          instanceSandbox.appendFoo = function(){
           core.getContainer.append("foo");
          };
        }
    
        // or load a something asynchronously
        core.myAsyncMethod(function(data){
    
          // do something...
          // now tell scaleApp that you're done
          done();
        });
      };
    
      // define a method that gets called when a module stops
      var onModuleDestroy = function(done){
        myCleanUpMethod(function(){
          done()
        });
      };
    
      // don't forget to return your methods
      return {
        init: onModuleInit,
        destroy: onModuleDestroy
      };
    
    });
    

    Usage:

    core.myCoreFunction() // alerts "Hello core plugin"
    
    var MyModule = function(sandbox){
      init: function(){ sandbox.appendFoo(); },  // appends "foo" to the container
    };
    

    Build browser bundles

    If you want scaleApp bundled with special plugins type

    grunt custom[:PLUGIN_NAME]
    

    e.g. grunt custom:dom:mvc creates the file scaleApp.custom.js that contains scaleApp itself the dom plugin and the mvc plugin.

    API

    scaleApp

    • scaleApp.VERSION - the current version of scaleApp
    • scaleApp.Mediator - the Mediator class
    • scaleApp.Sandbox - the Sandbox class
    • scaleApp.Core - the Core class

    Core

    // use default sandbox
    var core = new scaleApp.Core();
    
    // use your own sandbox
    var core = new scaleApp.Core(yourSandboxClass);
    
    • core.register(moduleName, module, options) - register a module
    • core.use(plugin, options) - register a plugin
    • core.use(pluginArray) - registers an array of plugins
    • core.boot(callback) - initialize plugins (will be executed automatically on ´start´)
    • core.start(moduleId, options, callback) - start a module
    • core.stop(instanceId, callback) - stop a module

    Mediator

    // create a mediator
    var mediator = new scaleApp.Mediator();
    
    // create a mediator with a custom context object
    var mediator = new scaleApp.Mediator(context);
    
    // create a mediator with cascaded channels
    var mediator = new scaleApp.Mediator(null, true);
    
    • mediator.emit(channel, data, callback)
    • mediator.on(channel, callback, context)
    • mediator.off(channel, callback)
    • mediator.installTo(context, force)
    • mediator.send(channel, payload, callback)
    • mediator.pipe(source, target, mediator)
    // subscribe
    var subscription = mediator.on(channel, callback, context);
    
    • subscription.detach - stop listening
    • subscription.attach - resume listening
    var fn  = function(){ /*...*/ };
    var obj = { emit: fn };
    
    // the installTo method prevents existing properties by default
    mediator.installTo(obj);
    obj.emit === fn // true
    
    // set the second paramater to 'true'
    // to force the mediator to override existing propeties
    mediator.installTo(obj, true);
    obj.emit === mediator.emit // true
    

    Sandbox

    This is the default sandbox of scaleApp. It's a better idea to use your own one.

    var sandbox =  new scaleApp.Sandbox(core, instanceId, options, moduleId)` - create a Sandbox
    
    • sandbox.emit is mediator.emit
    • sandbox.on is mediator.on
    • sandbox.off is mediator.off

    Changelog

    see CHANGELOG.md

    Testing

    npm test
    

    Examples

    Within the examples directory you can find some basic examples that might help you.

    Licence

    scaleApp is licensed under the MIT license. For more information have a look at LICENCE.txt.

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