preloader.js

A simple Javascript library for preload image and audio. The main feature:

set concurrency
set minimum loading time per resouce, for simulate slow load

Install

npm install --save preloader.js

Usage

Import

var Preloader = require('preloader.js')

Execute

var preloader = new Preloader({
    resources: ['assert/images/logo.png', 'assert/audios/bg.mp3'],
    concurrency: 4
})
preloader.addProgressListener(function (loaded, length) {
    console.log('loading ', loaded, length, loaded / length)
})
preloader.addCompletionListener(function () {
    console.log('load completed')
})
preloader.start()

PS: If no use module bundler (e.g.: webpack、browserify), you can direct reference

<script src="src/preloader.js"></script>

Introduce

configuration

resources Array

Default: [].

Preload resouce list. The files of postfix belong to ['mp3', 'ogg', 'wav'] to according audio handle.

PS：Resources in addition to here configuration, including configured attr value DOM node.
concurrency Number

Default: 0.

Concurrent number. 0 is no concurrency limit.
perMinTime Number

Default: 0. Unit: ms

Minimum loading time per resouce. Usually used to simulate load slow.
attr String

Default: data-preload.

DOM node attribute. Example: <img src="img/logo.png" data-preload/>, the 'img/logo.png' will been added in resources.
crossOrigin Boolean

Default: false.

If set to true, which will set the crossOrigin property on images to Anonymous for support images loaded from a CORS-enabled server.
onProgress Function

Default: null.

Every resouce load is completed the callback function. The effect same to addProgressListener.
onCompletion Function

Default: null.

All resouces load is completed the callback function. The effect same to addCompletionListener.

instance method

addProgressListener(Function)

Set every resouce load is completed the callback function

addCompletionListener(Function)

Set all resouces load is completed the callback function

get(String)

Get instances of completed

start()

Begin load. All ready after invoke.

License

MIT