Planck Loader

Provides for parallel and sequential data loading and progress observation.

Getting Started

Installing

npm install @takram/planck-loader

Example

The example below will load data1.json, data2.json and lib.js in parallel (in a JavaScript sense), whereas main.js will be loaded after loading lib.js.

import { Loader } from '@takram/planck-loader'

const progressBar = document.querySelector('#progress-bar')

const loader = new Loader([
  'path/to/data1.json',
  'path/to/data2.json',
  ['path/to/lib.js', 'path/to/main.js'],
])

loader.addEventListener('determinate', event => {
  progressBar.classList.remove('indeterminate')
})

loader.addEventListener('progress', event => {
  progressBar.style.width = `${event.target.progress * 100}%`
})

loader.load().then(requests => {
  progressBar.classList.add('completed')
  loader.loaders.forEach(loader => {
    console.log(loader.url, loader.request.response)
  })
}).catch(code => {
  progressBar.classList.add('failed')
  console.error(code)
})

API Reference

Loader

# new Loader(url1 [, url2 [, ...]])

The constructor that takes a sequence of URLs or arrays of URLs. The top level arguments will be loaded sequentially, and the second level will be loaded in parallel. Any further depth of array repeats cycles its behavior.

new Loader(a, b)
new Loader(a, [c, d], b)
new Loader(a, [c, [e, f], d], b)

• a and b are loaded sequentially
• c and d are loaded in parallel
• e and f are loaded sequentially

Likewise:

new Loader([a, b])
new Loader([a, [c, d], b])
new Loader([a, [c, [e, f], d], b])

• a and b are loaded in parallel
• c and d are loaded sequentially
• e and f are loaded in parallel

# loader.load()

Returns a Promise that resolves with an array of requests (XMLHTTPRequest). It rejects with a status code when one of the requests fails.

# loader.size

Number that indicates the size of total payloads in bytes, dispatching an size event when the value changes.

# loader.progress

Number that indicates the loading progress between 0-1 in total, dispatching an progress event when the value changes.

# loader.determinate

Boolean Becomes when the loader becomes able to determine the progress, dispatching an determinate event when the value changes.

# loader.completed

Boolean Becomes true when all of the requests completes loadind, dispatching a complete event when the value changes.

# loader.failed

Boolean Becomes true when any loader fails to load, dispatching an error event when the value changes.

License

The MIT License

Copyright (C) 2016-Present Shota Matsuda

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.