Extended module functionality

docs/marionette.application.module.md

@@ -22,9 +22,11 @@ your application, and serve as an event aggregator in themselves.
 * [Module Definitions](#module-definitions)
   * [Module Initializers](#module-initializers)
   * [Module Finalizers](#module-finalizers)
+  * [Initialize function](#initialize-function)
 * [The Module's `this` Argument](#the-modules-this-argument)
 * [Custom Arguments](#custom-arguments)
 * [Splitting A Module Definition Apart](#splitting-a-module-definition-apart)
+* [Extending Modules](#extending-modules)
 
 ## Basic Usage
 
@@ -332,6 +334,8 @@ console.log(MyApp.MyModule.someData); //=> public data
 MyApp.MyModule.someFunction(); //=> public data
 ```
 
+
+
 ### Module Initializers
 
 Modules have initializers, similarly to `Application` objects. A module's
@@ -367,6 +371,35 @@ MyApp.module("Foo", function(Foo){
 Calling the `stop` method on the module will run all that module's 
 finalizers. A module can have as many finalizers as you wish.
 
+### Initialize Function
+
+Modules have an `initialize` function which is distinct from its collection of initializers. `initialize` is immediately called when the Module is invoked, unlike initializers, which are only called once the module is started. You can think of the `initialize` function as an extension of the constructor.
+
+```js
+MyApp.module("Foo", {
+  startWithParent: false,
+  initialize: function( options ) {
+    // This code is immediately executed
+    this.someProperty = 'someValue';
+  },
+  define: function() {
+    // This code is not executed until the Module has started
+    console.log( this.someProperty ); // Logs 'someValue' once the module is started
+  }
+});
+```
+
+The `initialize` function is passed a single argument, which is the object literal definition of the module itself. This allows you to pass arbitrary values to it.
+
+```js
+MyApp.module("Foo", {
+  initialize: function( options ) {
+    console.log( options.someVar ); // Logs 'someString'
+  },
+  someVar: 'someString'
+});
+```
+
 ## The Module's `this` Argument
 
 The module's `this` argument is set to the module itself.
@@ -412,3 +445,26 @@ MyApp.module("MyModule", function(MyModule){
 MyApp.MyModule.definition1; //=> true
 MyApp.MyModule.definition2; //=> true
 ```
+
+## Extending Modules
+
+Modules can be extended. This allows you to make custom Modules to include in your Application.
+
+```
+var CustomModule = Marionette.Module.extend({
+  constructor: function() {
+    // Configure your module
+  }
+});
+```
+
+When attaching a Module to your Application you can specify what class to use with the parameter `moduleClass`.
+
+```
+MyApp.module("Foo", {
+  moduleClass: CustomModule,
+  define: function() {} // You can still use the definition function on custom modules
+});
+```
+
+When `moduleClass` is omitted, Marionette will default to instantiating a new `Marionette.Module`.

spec/javascripts/module.start.spec.js

@@ -222,4 +222,121 @@ describe("module start", function(){
 
   });
 
+  describe("when passing a custom module class in the object literal", function(){
+    var MyApp, MyModule, moduleStart, customModule, initializer;
+
+    beforeEach(function(){
+
+      MyApp = new Backbone.Marionette.Application();
+      initializer = sinon.spy();
+      customModule = Backbone.Marionette.Module.extend( { initialize: initializer } );
+
+      MyApp.module("MyModule", {
+        startWithParent: false,
+        moduleClass: customModule
+      });
+
+      MyApp.start();
+    });
+
+    it("should run the initialize function once", function(){
+      expect(initializer).toHaveBeenCalledOnce;
+    });
+  });
+
+  describe("when passing an extended custom module class in the object literal", function(){
+    var MyApp, MyModule, moduleStart,
+        customModule, customModuleTwo,
+        initializer, initializerTwo,
+        p1, p2, r1, r2;
+
+    beforeEach(function(){
+
+      p1 = 'val1';
+      p2 = 'val2';
+
+      MyApp = new Backbone.Marionette.Application();
+      initializer = sinon.spy();
+      initializerTwo = sinon.spy();
+      customModule = Backbone.Marionette.Module.extend({
+        initialize: initializer,
+        val1: p1,
+        val2: p1
+      });
+      customModuleTwo = customModule.extend({
+        initialize: initializerTwo,
+        val1: p2
+      });
+
+      MyApp.module("MyModule", {
+        startWithParent: false,
+        moduleClass: customModuleTwo,
+        define: function() {
+          r1 = this.val1;
+          r2 = this.val2;
+        }
+      });
+
+      MyApp.start();
+    });
+
+    it("should only run the latest initialize function once, and not the prototype initialize", function(){
+      expect(initializer).not.toHaveBeenCalled();
+      expect(initializerTwo).toHaveBeenCalledOnce;
+    });
+
+    it("should extend properties correctly", function() {
+      expect(r1).toBe(p2);
+      expect(r2).toBe(p1);
+    });
+
+  });
+
+  describe("when passing an initialize function as an option when calling `Application.module`", function(){
+    var MyApp, MyModule, moduleStart, initializer;
+
+    beforeEach(function(){
+
+      MyApp = new Backbone.Marionette.Application();
+      initializer = sinon.spy();
+
+      MyApp.module("MyModule", {
+        initialize: initializer
+      });
+
+      MyApp.start();
+    });
+
+    it("should run the initialize function once", function(){
+      expect(initializer).toHaveBeenCalledOnce;
+    });
+
+  });
+
+  describe("when passing an arbitrary set of arguments to `Application.module`", function(){
+    var MyApp, MyModule, moduleStart, initializer, options;
+
+    beforeEach(function(){
+
+      MyApp = new Backbone.Marionette.Application();
+      initializer = sinon.spy();
+
+      options = {
+        startWithParent: false,
+        p1: 'testValueOne',
+        p2: 'testValueTwo',
+        initialize: initializer
+      };
+
+      MyApp.module("MyModule", options);
+
+      MyApp.start();
+    });
+
+    it("should pass them to the initialize function", function(){
+      expect(initializer).toHaveBeenCalledWithExactly(options);
+    });
+
+  });
+
 });

src/marionette.application.js

@@ -77,13 +77,20 @@ _.extend(Marionette.Application.prototype, Backbone.Events, {
 
   // Create a module, attached to the application
   module: function(moduleNames, moduleDefinition){
+    var ModuleClass = Marionette.Module;
+
+    // Overwrite the module class if the user specifies one
+    if (moduleDefinition) {
+      ModuleClass = moduleDefinition.moduleClass || ModuleClass;
+    }
+
     // slice the args, and add this application object as the
     // first argument of the array
     var args = slice(arguments);
     args.unshift(this);
 
     // see the Marionette.Module object for more information
-    return Marionette.Module.create.apply(Marionette.Module, args);
+    return ModuleClass.create.apply(ModuleClass, args);
   },
 
   // Internal method to set up the region manager

src/marionette.module.js

@@ -3,8 +3,10 @@
 
 // A simple module system, used to create privacy and encapsulation in
 // Marionette applications
-Marionette.Module = function(moduleName, app){
+Marionette.Module = function(moduleName, app, options){
   this.moduleName = moduleName;
+  this.options = _.extend({}, this.options, options);
+  this.initialize = options.initialize || this.initialize;
 
   // store sub-modules
   this.submodules = {};
@@ -16,12 +18,22 @@ Marionette.Module = function(moduleName, app){
   this.startWithParent = true;
 
   this.triggerMethod = Marionette.triggerMethod;
+
+  if (_.isFunction(this.initialize)){
+    this.initialize(this.options);
+  }
 };
 
+Marionette.Module.extend = Marionette.extend;
+
 // Extend the Module prototype with events / listenTo, so that the module
 // can be used as an event aggregator or pub/sub.
 _.extend(Marionette.Module.prototype, Backbone.Events, {
 
+  // Initialize is an empty function by default. Override it with your own
+  // initialization logic when extending Marionette.Module.
+  initialize: function(){},
+
   // Initializer for a specific module. Initializers are run when the
   // module's `start` method is called.
   addInitializer: function(callback){
@@ -136,7 +148,7 @@ _.extend(Marionette.Module, {
     // Loop through all the parts of the module definition
     _.each(moduleNames, function(moduleName, i){
       var parentModule = module;
-      module = this._getModule(parentModule, moduleName, app);
+      module = this._getModule(parentModule, moduleName, app, moduleDefinition);
       this._addModuleDefinition(parentModule, module, moduleDefinitions[i], customArgs);
     }, this);
 
@@ -145,12 +157,18 @@ _.extend(Marionette.Module, {
   },
 
   _getModule: function(parentModule, moduleName, app, def, args){
+    var ModuleClass = Marionette.Module;
+    var options = _.extend({}, def);
+    if (def) {
+      ModuleClass = def.moduleClass || ModuleClass;
+    }
+
     // Get an existing module of this name if we have one
     var module = parentModule[moduleName];
 
     if (!module){
       // Create a new module if we don't have one
-      module = new Marionette.Module(moduleName, app);
+      module = new ModuleClass(moduleName, app, options);
       parentModule[moduleName] = module;
       // store the module on the parent
       parentModule.submodules[moduleName] = module;