Approaches to modular client-side Javascript without namespace pollution

Question

I\'m writing client-side code and would like to write multiple, modular JS files that can interact while preventing global namespace pollution.

index.html

Answer 1

I would strongly recommend you to go ahead with RequireJS.

---

The modules support approach (without requires/dependencies):

// moduleA.js

var MyApplication = (function(app) {

    app.util = app.util || {};

    app.util.hypotenuse = function(a, b) {
        return Math.sqrt(a * a + b * b);
    };

    return app;
})(MyApplication || {});

// ----------

// moduleB.js

var MyApplication = (function(app) {

    app.util = app.util || {};

    app.util.area = function(a, b) {
        return a * b / 2;
    };

    return app;
})(MyApplication || {});

// ----------

// index.js - here you have to include both moduleA and moduleB manually
// or write some loader

var a = 3,
    b = 4;
console.log('Hypotenuse: ', MyApplication.util.hypotenuse(a, b));
console.log('Area: ', MyApplication.util.area(a, b));

Here you're creating only one global variable (namespace) MyApplication, all other stuff is "nested" into it.

Fiddle - http://jsfiddle.net/f0t0n/hmbb7/

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**One more approach that I used earlier in my projects - https://gist.github.com/4133310 But anyway I threw out all that stuff when started to use RequireJS.*