energize.js

energize

An assets loader that loads everything. Say you have some third party libraries with their own loader modules, you can pipe the loading progress into energize's loading pipeline. It also does basic loading for image, json, jsonp, text, video and audio.

Usage

Simple batch loading

Add several assets to the loader and get the percent of the batch loading.

// assuming you are using CommonJS
var energize = require('energize');

// load the asset with a certain type
energize.add('1.jpg', {type: 'image'});

// or let it guess the type by the url extension
energize.add('2.jpg');

// you can also define the weight of the asset which is 1 by default
energize.add('3.jpg', {weight: 2});

energize.start(function(percent) {

    // assuming the files are loaded in the same order as above
    // it will be logged as 0.25, 0.5, 1.0
    console.log(percent);

    if (percent === 1) {
        init();

        // the listender was removed at this point and it
        // will not have any stacked async issues so you can
        // load something else again.
        energize.add(...);
        energize.start(...);
    }
});

Individual asset callback

You can add an onLoad callback to an individual asset.

energize.add('data.json', {
    onLoad: function(data) {
        console.log(data);
    }
});
energize.add('img.jpg');
energize.start(...);

Load a single item out of the energize pipline

For all features that work with batch loading, it works with individual asset loading as well. Basically all you need is to change the add() into load()

energize.load('data.json', {
    onLoad: function(data) {
        console.log(data);
    }
});

Initial content

Sometimes when you add the loading query to the batch loader, you want to have access to the asset instance immediately. This feature only works with asset type: image, video and audio

var img = energize.add('img.jpg').content;

energize.start(...);

Working with third-party library loaders like THREE.js JSON Loader

energize.load('mesh.json', {

    type: 'any',

    loadFunc: function(url, cb) {

        var loader = new THREE.JSONLoader();

        loader.load(url, function(geometry, material) {
            var mesh = new THREE.Mesh(geometry, material);

            // tell energize the item is loaded and store
            // the mesh instead as content
            cb(mesh);
        });
    }
});

No Cache

Normally after an item is loaded, the content will be stored and if you fetch the same url, it will not download the content again. But you can set noCache to true in the item config and bypass this feature. It will remove the reference after the file is loaded.

energize.load('img.jpg', {
  noCache: true
});

Individual asset preloading

You can also add a listener to the individual asset. This feature only works with asset types json, textandany`.

energize.add('data.json', {
    type: 'json',
    weight: 5,
    hasLoading: true,
    onLoading: function(percent) {
        console.log(percent);
    }
});

Individual asset preloading with third-party libraries

This following example is to show you when you are using any asset type, you can do whatever you want.

energize.add('a_fake_loader', {
    type: 'any',
    weight: 50,
    hasLoading: true,
    onLoading: function(percent) {
        console.log('loading: ' + ~~(percent * 100) + '%');
    },
    onLoad: function(content) {
        // some content here
        console.log('loaded: ' + content);
    },
    loadFunc: function(url, cb, loadingSignal) {
        var count = 0;
        var interval = setInterval(function() {
            count++;
            loadingSignal.dispatch(count / 10);
            if (count == 10) {
                clearInterval(interval);
                cb('some content here');
            }
        }, 100);
    }
});

add a chunk of asset

energize.addChunk(['1.jpg', '2.jpg', '3.jpg'], 'image');

// let energize guess the types
energize.addChunk(['1.jpg', '2.jpg', '3.jpg']);

Add DOM Images (experimental)

It adds all images through the image tag and background images.

energize.addChunk(document.body.querySelectorAll('*'));

Multi-batch Loader instances

For some reason if you want to have 2 loaders, you can create a new one like this:

var energize = require('energize');

var batchLoader = energize.create();
batcherLoader.add(...);

Cross Origin

var energize = require('energize');

// set everything to be cross-origin within a domain
energize.setCrossOrigin('http:///mydomain/', 'anonymous')

// set cross-origin for individual load item
energize.add('http://anotherdomain/image.jpg,', {
  crossOrigin: 'anonymous'
})

Installation

Download the standalone version HERE

npm install energize.js