$async IIFE generator enables to easily create a pre-concatenated selection of $async
modules that is additionally optimized using Google Closure Compiler.
The generator is available online on https://style.tools/iife/
IIFE or Immediately-invoked Function Expressions is a coding pattern for loading a script. An IIFE can be used in the browser safely.
<script async src="js/async-iife.js" data-c='[["css/sheet1.css",{"href": "https://cdn.com/css/sheet2.css","render_timing": "requestAnimationFrame"}]]'></script>
The IIFE can be optmized using Google Closure Compiler with Advanced Optimizations for optimal compression.
The Node.js module can be executed as a CLI program from the command-line.
npm install @style.tools/async-iife
The provided iife-cli.js script can be used from the command-line. The NPM package contains a npm run iife
script.
Display usage information and a list with available modules.
npm run iife -- --help
The following command shows how to create an IIFE with unary
format, output to path/to/iife.js
and with 3 modules that automatically load the required dependencies.
npm run iife -- --format unary --compress --output path/to/iife.js --modules css-loader,localstorage,timing
Short flags and a space separated module list are supported.
npm run iife -- -f unary -c -o path/to/iife.js -m "css-loader localstorage timing"
When omitting the --output
flag the script is printed to the console, e.g. for > output.js
.
// load Node.js moduleconst iife = require('@style.tools/async-iife');// return script text for inlining// uses memory-cache @link https://www.npmjs.com/package/memory-cacheiife.generate(['css-loader', 'timing'], {debug: true, // debug sourcesformat: 'unary' // !function(){ ... }()}).then(function(iife_script) {// iife_script contains the IIFE script text});// output to fileiife.generate(['css-loader', 'timing'], {compress: true, // Google Closure Compiler API compressionformat: 'wrap', // (function(){ ... })()output: 'path/to/iife.js',output_stats: true // return { modules:[], size:0, gzip_size:0 }}).then(function(stats) {// iife.js writtenconsole.log(stats);});
The Node.js module can be used efficiently within a Node.js CMS. IIFE's are cached in memory using memory-cache.
Warning: the generator depends on the free Google Closure Compiler API that may not be 100% reliable. When using the generator in production it may be an option to use a local Google Closure Compiler service.