How to emulate "window" object in Nodejs?

Question

When running in a browser, everything attached to the "window" object will automatically become global object. How can I create an object similar to that in Nodejs?

mySpecialObject.foo = 9;
var f = function() { console.log(foo); };
f();  // This should print "9" to console

Answer 1

If you were to compare the Web Console to Node running in terminal (both Javascript) :

window <-> global (Note: GLOBAL is deprecated)

in Web Console : window.wgSiteName (random to show functionality)

in Node (Terminal): global.url

document <-> process (Note: program process running right now)

in Web Console : document.title

in Node (Terminal): process.title

Answer 2

You can use the predefined object global for that purpose. If you define foo as a property of the global object, it will be available in all modules used after that.

For example, in app.js:

var http = require('http');
var foo = require('./foo');

http.createServer(function (req, res) {
  //Define the variable in global scope.
  global.foobar = 9;
  foo.bar();    
}).listen(1337, '127.0.0.1');

And in foo.js:

exports.bar = function() {
  console.log(foobar);
}

Make sure you don't use the var keyword as the global object is already defined.

For documentation, check out http://nodejs.org/api/globals.html#globals_global.