skid / microload

A micro async script loader.

Microload

Microload is a very small asynchronous script and stylesheet loader.

Demo

Here's microload: http://skid.github.io/microload.html

Usage

Simple as this:

microload('dependency_1.js', ['dependee_1.js', 'dependee_2.js', 'mystyles.css'], function(){
  console.log("Scripts Loaded");
});

The microload function accepts strings, arrays of strings and an optional function as the last argument.

Each string will be treated as a URL to a script or a stylesheet, depending on the extension. Each URL will be loaded consecutively. Microload won't attempt to load the second argument until the first argument is already loaded.

Microload also accpets arrays of URLs as arguments. These work just the same, except that all the URLs in the array will be loaded in parallel. In the next example we are loading jQuery and underscore in parallel (since they don't depend on other librares) and only after they are both loaded, we load our application scripts.

microload(['jquery.js', 'underscore.js'], ['application-1.js', 'application-2.js'], 'application-1-dependee.js');

Finally, if the last argument is a function, microload will execute it once all resources are succesfully loaded.

microload(['jquery.js', 'underscore.js'], 'application.js', 'application-dependee.js', function(){
  // Run something once everything is loaded
  application.init();
});

Microload will not load the same URL twice, but it will execute a callback queued after an already-loaded resource. For instance:

microload('application.js', function(){
  application.init();
  
  // Later ...
  microload('application.js', function(){
    // Oops. We load application.js again
    // This callback will execute immediately since application.js is already loaded.
  });
});

Microload will also queue callbacks for resources with the same path

microload('script-1.js', function(){
  // This will wait for script-1.js to load
});
microload('script-1.js', function(){
  // The script-1.js won't be loaded again, but this callback 
	// will execute once the previous load call returns.
});

Compatibility

Works with modern browsers (IE8+).

License

MIT