Develop Reference

How to guarantee dependent class in javascript with requirejs

I was hoping that the following code would guarantee that parentClass is loaded before childClass, and that both would be loaded before startMyApp was called.
require([
"parentClass",
"childClass"
], function (parentClass, childClass){
Main.startMyApp();
});
If not, how can I guarantee that? Main, is an object. Child class is defined as such:
var childClass = function childClass() {
this.name = 'some name';
};
childClass.prototype = new parentClass();
childClass.prototype.constructor = childClass;
And here is parentClass:
var parentClass = function parentClass() {
};
parentClass.prototype.myFunction = function myFunction(){
//do something
}
I am trying to avoid adding define's to all of my classes, I've got dozens. Is that the only way to guarantee class are available when I need them? Thanks!

The call require(["parentClass", "childClass"], ... tells RequireJS to load both modules but this call does not coerce the order in which the modules are loaded. What does coerce the order of the modules are the dependencies you establish between the modules.
Since this is your own code, and you've decided to use RequireJS, then you should write proper AMD modules. To establish dependencies you list them as the first argument of your define calls (if needed). For your parent class:
define(function () {
var parentClass = function parentClass() {
};
parentClass.prototype.myFunction = function myFunction(){
//do something
}
return parentClass;
});
For your child class:
define(['parentClass'], function (parentClass) {
var childClass = function childClass() {
this.name = 'some name';
};
childClass.prototype = new parentClass();
childClass.prototype.constructor = childClass;
return childClass;
});
Then whatever other modules needs childClass just require your childClass module and parentClass is guaranteed to be loaded before childClass because parentClass is listed as a dependency in the define call.

You want to use the shim config, for example:
require.config({
paths: {
jquery: ['../bower_components/jquery/jquery.min'],
underscore: ['../bower_components/underscore/underscore-min']
app: 'app'
},
shim: {
underscore: {
deps: ['jquery'],
exports: '_'
},
waitforimages: {
deps: ['jquery']
},
cyclotron: {
deps: ['jquery']
},
placeholder: {
deps: ['jquery']
},
app: {
deps: ['jquery', 'underscore', 'fastclick', 'spinjs', 'waitforimages', 'backgroundCheck', 'raphael', 'swipe', 'history', 'cyclotron', 'placeholder']
}
}
});
require([
'app'
]);
this isn't the most optimized example, but basically, if you say that something is a dep of another script, it will make sure to load those files. So you can see in this example, I am telling require that these plugins require jquery, and my app requires jquery and these plugins.
This way everything gets loaded before my app.js

RequireJS error callback (errback) not getting called

I'm writing a modular web app using RequireJS for module loading and dependency injection.
From my bootstrap.js file I load Application.js and initialize it, passing in an array of modules that are to be "loaded"(1) by the Application. When the initialization finishes, the Application will call a function to signal that it's done loading.
I'm loading the modules asynchronously (in regard to each other) using require(["module"], callback(module), callback(error)).
The problem that I'm having with this is that the error callback (errback) is not called when a module fails to load (at least on Chrome when the server responds with a 404 status code).
I can see the error in the Google Chrome Developer Tools Console, but the errback isn't called:
GET http://192.168.1.111:8812/scripts/modules/InexistentModule/manifest.js 404 (Not Found)
Uncaught Error: Load timeout for modules: modules/InexistentModule/manifest
Has anyone experienced gotten around this issue with RequireJS errbacks? If so, how?
(1) Actually, I'm just loading module manifests, not the entire modules, so that I can display icons for them and register their routes using Backbone.SubRoute
The libraries that I'm using (none of them are minified):
RequireJS 1.0.8
Underscore 1.6.0
jQuery 1.11.0
Backbone 1.1.2
Backbone.SubRoute 0.4.1
Out of the libraries above, only RequireJS and Underscore are used directly by me at the moment.
I've used Underscore for currying when passing the success/failure callbacks to Require in order to pass in the i from my loop as the index parameter. For the success callback, this works wonderfully and I think that this does not affect the errback (I've tested with a simple function of arity 1, instead of the partial function returned by _.partial and the function is still not called in case of a 404 error).
I'll post my bootstrap.js and Application.js files here as they might provide more info on this.
Thank you!
bootstrap.js
require.config({
catchError: true,
enforceDefine: true,
baseUrl: "./scripts",
paths: {
"jquery": "lib/jquery",
"underscore": "lib/underscore",
"backbone": "lib/backbone",
"backbone.subroute": "lib/backbone.subroute"
},
shim: {
"underscore": {
deps: [],
exports: "_"
},
"backbone": {
deps: ["jquery", "underscore"],
exports: "Backbone"
},
"backbone.subroute": {
deps: ["backbone"],
exports: "Backbone.SubRoute"
}
}
});
define(["jquery", "underscore", "backbone", "Application"],
function ($, _, Backbone, Application) {
var modules = ["Home", "ToS", "InexistentModule"];
var defaultModule = "Home";
var onApplicationInitialized = function()
{
require(["ApplicationRouter"], function(ApplicationRouter){
ApplicationRouter.initialize();
});
}
Application.initialize(modules, defaultModule, onApplicationInitialized);
}
);
Application.js
define([
'jquery',
'underscore',
'backbone'],
function($,_,Backbone){
var modules;
var manifests = [];
var routers = [];
var defaultModule = "";
var totalModules = 0;
var loadedModules = 0;
var failedModules = 0;
var onCompleteCallback = function(){};
var onModuleManifestLoadComplete = function(index, manifest){
manifests[index] = manifest;
console.log("Load manifest for module: " + modules[index] + " complete");
//TODO: init module
loadedModules++;
if(totalModules == (loadedModules + failedModules))
onCompleteCallback();
};
var onModuleManifestLoadFailed = function(index, err){
console.log("Load manifest for module: " + modules[index] + " failed");
failedModules++;
if(totalModules == (loadedModules + failedModules))
onCompleteCallback();
};
var initialize = function(_modules, _defaultModule, callback){
defaultModule = _defaultModule;
modules = _modules;
manifests = Array(modules.length);
totalModules = modules.length;
onCompleteCallback = callback;
for(i=0; i<modules.length; i++){
require(['modules/'+modules[i]+'/manifest'],
_.partial(onModuleManifestLoadComplete, i),
_.partial(onModuleManifestLoadFailed, i));
};
};
return {
modules: modules,
manifests: manifests,
routers: routers,
defaultModule: defaultModule,
initialize: initialize
};
});

You indicate you are using RequireJS 1.0.8. I've checked the documentation for the 1.x series and find nothing about errbacks. This page actually indicates that errbacks were introduced in the 2.x series.
Also the shim is something that was introduced in the 2.x series. So right now, RequireJS is ignoring your shims.

Strange Requirejs behavior when loading Markdown

I have a requirejs module in which I am trying to load markdownjs. Here is the file:
define(function(require) {
'use strict';
var Backbone = require('backbone');
var blogCollectionTemplate = require('hbs!app.templates/blog.collection.view');
var BlogModelView = require('views/blog.item.view');
var markdown = require('markdown');
var BlogCollectionView = Backbone.View.extend({
template: blogCollectionTemplate,
initialize: function() {
debugger;
},
render: function() {
this.$el.html(this.template());
this.renderAll();
return this;
},
renderAll: function() {
var that = this;
this.collection.each(function(blog) {
that.renderItem(new BlogModelView({model: blog}));
});
},
renderItem: function(blog) {
this.$el.find('#blog-posts').append(blog.render(blog).el);
}
});
return BlogCollectionView;
});
Here is my require.config:
define(function() {
require.config({
hbs : {
templateExtension : 'hbs',
disableHelpers: true,
disableI18n : true
},
shim: {
'backbone': {
deps: [
'underscore',
'jquery'
],
exports: 'Backbone'
},
bootstrap: {
deps: [ 'jquery' ]
},
DlHighlight: {
exports: 'DlHighlight'
},
'jqueryMockAjax': {
exports: '$.mockjax',
deps: ['jquery']
},
json2 : {
exports: "JSON"
},
'underscore': {
exports: '_'
}
},
paths: {
backbone: 'libs/backbone/backbone',
bootstrap: 'libs/bootstrap/dist/js/bootstrap',
DlHighlight: 'libs/hl/hl-all',
highlight: 'libs/highlightjs/highlight.pack',
jquery: 'libs/jquery/jquery',
jqueryMockAjax: 'libs/jquery-mockjax/jquery.mockjax',
markdown: 'libs/markdown/lib/markdown',
text: 'libs/text/text',
underscore: 'libs/underscore/underscore',
hbs: 'libs/hbs/hbs',
handlebars: 'libs/hbs/Handlebars',
i18nprecompile: 'libs/hbs/hbs/i18nprecompile',
json2 : 'libs/hbs/hbs/json2',
'app.templates': '../templates/'
}
});
});
Here is the strange behavior. In my initialize, when I hit the debugger, I have access to the markdown object that I have imported, BUT if I have try to use the markdown object, then it is always undefined. If I put markdown in the initialize or in one of the render methods, the markdown variable is undefined. It makes no sense, but is there some behavior that I dont understand about requirejs. Any ideas?

After reading the code of a bower installation of markdown-js, I found that what bower installs won't work with RequireJS as-is. Try adding this shim:
"markdown": {
exports: "markdown"
}
As to why were you able to get a value for markdown in the debugger without the shim, I believe you were getting it (perhaps without realizing it) from the global scope. Markdown-js installs itself into the global scope (window.markdown, which is then accessible as markdown if no other variable interferes with it) when it is loaded. This is speculation but it fits the facts.

You can require all of those modules in the define clause itself:
define([
'backbone',
'hbs!app.templates/blog.collection.view',
'views/blog.item.view',
'markdown'
], function (
Backbone,
blogCollectionTemplate,
BlogModelView,
markdown
) {
'use strict';
// do stuff
});
Also, what do you mean by "If I put markdown in the initialize or in one of the render methods"? Do you mean actually explicitly requiring markdown in initialize and render? Is there any reason to not just load markdown in the define clause as labeled above?
If you are explicitly requiring markdown in initialize or render, I am not sure why that would return undefined, but let me know if moving requirements to the define clause fixes your issue (or if you can't do that). Perhaps you could post the code in the markdown module (if it's not a library that is)?

RequireJS + oCanvas with self-invoking functions

I have troubles with using oCanvas - it doesn't support AMD out of box so in RequireJS I define a shim:
configuration.js
require(
function () {
requirejs.config({
shim: {
'lib/ocanvas': {
exports: ['oCanvas']
}
}
});
}
);
The way I load shim-related configuration (I think it's enough to add it to require to the entry point file):
require(['configuration','main'],
function (configuration, main) {
main.startUniverse();
}
);
The problem is I cannot get the oCanvas object in my JS files:
define(['lib/ocanvas'],
function (oCanvas) {}
It appears undefined here. In oCanvas sources I see that there are 2 self-invoking functions and they put the oCanvas object into global state like that: window.oCanvas = oCanvas. Maybe this doesn't work for RequireJS?

require(
function () {
requirejs.config({
shim: {
'lib/ocanvas': {
exports: 'oCanvas'
}
}
});
}
);
Try passing it as a string not an array?

Instead of requirejs.config I now use require.config and pass an object there:
require.config({
shim: {
'lib/ocanvas': {
exports: 'oCanvas'
}
}
});
That worked for me.

Configuring modules with RequireJS when config depends on RequireJS

Apologies if I have missed this in the docs. Basically I want to use the RequireJS module configuration feature. I would like to centrally manage the config values given to modules in a package.
This is an example from the docs:
requirejs.config({
config: {
'bar': {
size: 'large'
},
'baz': {
color: 'blue'
}
}
});
//bar.js, which uses simplified CJS wrapping:
define(function (require, exports, module) {
//Will be the value 'large'
var size = module.config().size;
});
//baz.js which uses a dependency array,
define(['module'], function (module) {
//Will be the value 'blue'
var color = module.config().color;
});
My problem is that my configuration info will be a little more complex, and will itself have dependencies. I would like to do:
requirejs.config({
config: {
'bar': {
path: path.dirname(module.uri)
key: crypto.randomBytes(64)
},
}
});
Where variables in my config need to use requireJS to evaluate.
To me it would make sense for there to be a logical separation between the RequireJS configuration - the config necessary to load modules - and the user's module configuration. But I am currently struggling to find this :(

For this sort of solution, I would have the module depend on a "config" module that you can swap for a different one using paths config. So if "bar" needed some config, "bar.js" would look like:
define(['barConfig'], function (config) {
});
Then barConfig.js could have your other dependencies:
define(['crypto'], function (crypto) {
return {
key: crypto.randomBytes(64)
}
});
Then, if you needed different configs for say, production vs. dev, use paths config to map barConfig to other values:
requirejs.config({
paths: {
barConfig: 'barConfig-prod'
}
});

I think the proper way to do this is to make a config module...
// config.js
define(['module', 'path', 'crypto'], function(module, path, crypto) {
return {
path: path.dirname(module.uri)
key: crypto.randomBytes(64)
};
});
Then use it in other modules...
// bar.js
define(['config'], function (config) {
var key = config.key;
});
You can then make it as complicated as you like!
EDIT: You could pollute the global namespace for this special class...
define(['module', 'path', 'crypto'], function(module, path, crypto) {
window.config = {
path: path.dirname(module.uri)
key: crypto.randomBytes(64)
};
});
Add it to the top level require call:
require(['config', 'main']);
Then you can use it without always adding it to your define:
// bar.js
define([], function() {
var key = config.key;
});

Having thought about this a little more I have come up with a workaround. It is not particularly pretty but it does seem to work.
I simply do requireJS(...) twice, first to create the config, and second to load the application modules with the config..
requireJSConfig =
baseUrl: __dirname
nodeRequire: require
# Create the require function with basic config
requireJS = require('requirejs').config(requireJSConfig)
requireJS ['module', 'node.extend', 'crypto', 'path'], (module, extend, crypto, path) ->
# Application configuration
appConfig =
'bar':
path: path.dirname(module.uri)
key: crypto.randomBytes(64) # for doing cookie encryption
# get a new requireJS function with CONFIG data
requireJS = require('requirejs').config(extend(requireJSConfig, config: appConfig))
requireJS ['bar'], (app) ->
###
Load and start the server
###
appServer = new app()
# And start the app on that interface (and port).
appServer.start()
And in bar.coffee
# bar.coffee
define ['module'], (module) ->
# config is now available in this module
console.log(module.config().key)

Riffing on what #jrburke is saying, I found the following pattern to be quite useful: define a config module and it's dependencies in the main.js just before the invocation of require.config().
main.js
define('config', ['crypto'], function (crypto) {
return {
'bar': {
key: crypto.randomBytes(64)
},
};
});
requirejs.config({
deps: ['app'],
});
app.js
require(['config'], function (config){
// outputs value of: crypto.bar.key
console.log(config.bar.key);
});
Plnkr Demo: http://plnkr.co/edit/I35bEgaazEAMD0u4cNuj