Autoloading symbols via source code grokking

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autoload -- Automatically load symbols in NodeJS


In NodeJS, and CommonJS in general, it's difficult to depend on common globals to be defined when you need them. This has led to very chatty or verbose boilerplate in applications to grab handles to functions and objects in every module in a project.
Generally module exports are used to define pseudo-classes or pseudo-namespaces which make sense as as globals. The problem is that even if your module defines its exports as global there's no way to be sure the module you depend on has been required or not. autoload attempts to ease this situation.


npm install autoload


In your top-level script, call autoload and registeredGlobalsAutoloader to initialize a typical autoloading environment:
var autoload = require('autoload');
autoload.autoload(__dirname, [autoload.registeredGlobalsAutoloader(require)], function() {
	<< your regular code goes here >>
<< don't put code here, as autoload is not ready yet! >>
To register a global as autoloadable, in another module you would do:
registerGlobal(function MyGlobalFunction() {
	<< function here >>
When you call autoload it will search __dirname for Javascript files and attempt to find all globals which could be defined (via registerGlobal). After it finds those symbols it registers autoloading getters on the global object (but does not actually require the module). When the getter is invoked the module is require'd and the symbol is returned.
Be sure to look at the source code for registeredGlobalsAutoloader, as you can use this library to autoload symbols in scopes outside of global as well, or you can implement your own global exporting pattern too. For instance of you prefer global.MySymbol = ... or MySymbol = ... you could wire that up. I prefer having the global be super explicit which is why I made registerGlobal().