import.js

Dependency loader plugin (only 3KB). Loads plugin dependencies (JS/CSS), stores them into the local storage and a lot more. A refactored and extended version of loadmodule.js. This plugin uses a customized version of the awesome basket.js from Addy Osmani.

Support: IE9+

Why another dependency loader?

Most of the frontend modules I develop consist of styles, javascript plugins and or custom scripts and related DOM elements. What I needed was a dependency loader checking the existence of a module in the DOM or if a given condition like touch events is true or not and loading the dependecies when and only when the given condition is true. That's pretty much it.

Think of it as the spine of your web application. Please read on to get an idea what import.js is capable of and what you can achieve with it.

TBD

• remove jqQery dependency -> DONE
• code review -> DONE
• tests
• performance optimizations

Get started

First include basket.full.custom.min.js and ``import.min.js``` to your template.

<script src="dist/basket.full.custom.min.js"></script>
<script src="dist/import.min.js"></script>

Then proceed to use import.js to lazily load the needed modules dependencies.

// ATTENTION: jQuery is not required!
$(function() {

	var loading = window.import([
		{
			condition: 'body',
			fetch: [
				'some/dep/path/styles.css',
				'some/dep/path/script.js'
			],
			callback: [
				{ method: myMethod, param: 'foo' },
				{ method: anotherMethod, param: { text: 'bar' } },
				{ method: toImportOrNotToImport }
			],
			unique: 0
		},
		{
			condition: window.innerWidth <= 480,
			fetch: [
				'some/other/dep/path.js'
			],
			event: [
				{ name: 'my-custom-event', data: ['someStringParam', 'anotherStringParam'] },
				{ name: 'another-custom-event', data: { hello: 'world' } }
			],
			unique: new Date().getTime()
		}
	], true, 60000);
	
	loading.then(function() {
		alert('Hooray, everything loaded');
	});
});

To see import.js in action clone this repo install the node_modules and type grunt sync on your console to see the example.

Be careful with cross site requests, in other words avoid them. Some browser have problems with that and with some browser I mean IE.

How does it work

The main part of the whole thing is the sorting of the modules.

1. Check if the condition is true. If it's false, the module will be deleted from the stack
2. If it's a DOM Element get the top offset and use this value for sorting
3. Sort the modules by their top offset. Boolean values have the lowest priority
4. Load

Documentation

Parameters

Order	Type	Description
1	{Array}	Array of module objects to be loaded
2	{Boolean}	Wether the loading status should be set (to the body) or not
3	{Number}	The loading timeout in milliseconds (Default: 5000ms)

Options

Name	Type	Description
condition*	{*}	The main entry point for import.js. If this condition is true, the dependencies will be loaded.
fetch*	{Array}	An array of file references to be loaded. Allowed are CSS and JS files.
event	{Array}	A list of custom events and related parameters to be fired, when the module dependencies have been loaded. NOTE: If you're using jQuery for eventlisteners you'll find the event data within the originalEvent object
callback	{Array}	A list of callbacks to be called, when the module has been loaded
unique	{Number/String}	If this value changes the modules' dependecies will be refetched from the server
order	{Number}	Order in which the module will be loaded

* mandatory

Thrown events

Eventname	Description/Occurance
on-module-loaded	Is triggered after each loaded module
on-loading-done	Is triggered when all modules have been loaded successfully
on-loading-error	Will be triggered when a dependecy could not be loaded for some kind of reason

Classes set to the body and other DOM elements

Classname	Description
on-loading	The initial loading state
on-loading-0, on-loading-10, on-loading-20, ...	The state of the loading in tens steps
on-loading-done	Will be attached to body when all modules have been loaded
on-loading-complete	Will be attached to the body when the whole loading process is done

LICENCE

The code is available under MIT Licence, so do whatever you want to do with it.