A library for loading JavaScript files asynchronously. It loads script files by injecting script tags into DOM during runtime.
You can install this library using npm.
npm install --save @bigcommerce/script-loader
To load a single script:
import { createScriptLoader } from '@bigcommerce/script-loader';
const loader = createScriptLoader();
loader.loadScript('https://cdn.foo.bar/main.js')
.then(() => {
console.log('Loaded!');
});
To load multiple scripts:
loader.loadScripts([
'https://cdn.foo.bar/vendor.js',
'https://cdn.foo.bar/main.js',
]);
To load a script with async
attribute:
loader.loadScript('https://cdn.foo.bar/main.js', { async: true });
To preload or prefetch a script:
loader.preloadScript('https://cdn.foo.bar/chunk.js');
loader.preloadScript('https://cdn.foo.bar/another-chunk.js', { prefetch: true });
A prefetched script is a low priority resource, therefore it will be downloaded in the background when the browser is idle. On the other hand, a script without prefetch
option will be marked as a high priority resource and downloaded immediately.
Please note that the preloaded or prefetched script won't be executed. It will just be downloaded to the browser cache. To attach it to the document and execute it, you will need to call loadScript
with the same URL.
To preload or prefetch multiple scripts:
loader.preloadScripts([
'https://cdn.foo.bar/chunk.js',
'https://cdn.foo.bar/another-chunk.js',
]);
loader.preloadScripts([
'https://cdn.foo.bar/chunk.js',
'https://cdn.foo.bar/another-chunk.js',
], { prefetch: true });
For browsers that don't have the ability to preload
or prefetch
resources, scripts will be loaded using regular Ajax requests instead.
To load a single stylesheet:
import { createStylesheetLoader } from '@bigcommerce/script-loader';
const loader = createStylesheetLoader();
loader.loadStylesheet('https://cdn.foo.bar/main.css')
.then(() => {
console.log('Loaded!');
});
To load multiple stylesheets:
loader.loadStylesheet([
'https://cdn.foo.bar/vendor.css',
'https://cdn.foo.bar/main.css',
]);
To prepend, instead of append, a stylesheet to the head of a document:
loader.loadStylesheet('https://cdn.foo.bar/main.css', { prepend: true });
To preload or prefetch a stylesheet:
loader.preloadStylesheet('https://cdn.foo.bar/chunk.css');
loader.preloadStylesheet('https://cdn.foo.bar/another-chunk.css', { prefetch: true });
Similar to a preloaded script, a preloaded or prefetched stylesheet won't take an effect until it is attached to the document. To do it, you will need to call loadStylesheet
with the same URL.
loader.preloadStylesheets([
'https://cdn.foo.bar/chunk.css',
'https://cdn.foo.bar/another-chunk.css',
]);
loader.preloadStylesheets([
'https://cdn.foo.bar/chunk.css',
'https://cdn.foo.bar/another-chunk.css',
], { prefetch: true });
To release:
npm run release
To see other available commands:
npm run
MIT