How to get the global object in JavaScript?

user_151312 0
Viewed 59082

I want to check in a script if a certain other module is already loaded.

if (ModuleName) {
    // extend this module
}

But if ModuleName doesn't exist, that throws.

If I knew what the Global Object was I could use that. 

if (window.ModuleName) {
    // extend this module
}

But since I want my module to work with both browsers and node, rhino, etc., I can't assume window.

As I understand it, this doesn't work in ES 5 with "use strict";

var MyGLOBAL = (function () {return this;}()); // MyGlobal becomes null

This will also fail with a thrown exception

var MyGLOBAL = window || GLOBAL

So it seems like I'm left with 

try {
    // Extend ModuleName
} 
catch(ignore) {
}

None of these cases will pass JSLint.

Am I missing anything?

global javascript
10 Answers

ECMAScript will be adding this to its standard soon: https://github.com/tc39/proposal-global

Until its done, this is what's recommended:

var getGlobal = function () {
    // the only reliable means to get the global object is
    // `Function('return this')()`
    // However, this causes CSP violations in Chrome apps.
    if (typeof self !== 'undefined') { return self; }
    if (typeof window !== 'undefined') { return window; }
    if (typeof global !== 'undefined') { return global; }
    throw new Error('unable to locate global object');
};
user_1423170
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