@style.tools/async-iife
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Node.js IIFE generator for @style.tools/async. Module and CLI program.
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# `$async` IIFE generator
A Node.js IIFE generator for [@style.tools/async](https://github.com/style-tools/async).
An online version of the IIFE generator is available on [https://style.tools/iife/](https://style.tools/iife/)
Documentation is available on [docs.style.tools/async/iife-generator](https://docs.style.tools/async/iife-generator).
# Install
```bash
npm install @style.tools/async-iife
```
# What is IIFE?
IIFE ([Immediately-invoked Function Expressions](https://medium.com/@vvkchandra/essential-javascript-mastering-immediately-invoked-function-expressions-67791338ddc6)) is a coding pattern for loading a script. An IIFE can be used in the browser safely.
The IIFE generator makes it easy to generate an IIFE with a selection of [$async](https://github.com/style-tools/async) modules. The IIFE generator provides compression via Google Closure Compiler (GCC) with _Advanced mode_ for the best performance in all browsers.
The IIFE generator can be executed as a CLI program from the command-line, as a Node.js module and as a browser script (see [https://style.tools/iife/](https://style.tools/iife/) for an online version).
# Usage
## CLI
The provided [iife-cli.js](https://github.com/style-tools/async-iife/blob/master/iife-cli.js) script can be used from the command-line. The NPM package contains a `npm run iife` script.
### Examples
Display usage information and a list with available modules.
```bash
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.
```bash
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.
```bash
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`.
## Node.js module
```javascript
// load Node.js module
const iife = require('@style.tools/async-iife');
// return script text for inlining
// uses memory-cache @link https://www.npmjs.com/package/memory-cache
iife.generate(['css-loader', 'timing'], {
debug: true, // debug sources
format: 'unary' // !function(){ ... }()
}).then(function(iife_script) {
// iife_script contains the IIFE script text
});
// output to file
iife.generate(['css-loader', 'timing'], {
compress: true, // Google Closure Compiler API compression
format: 'wrap', // (function(){ ... })()
output: 'path/to/iife.js',
output_stats: true // return { modules:[], size:0, gzip_size:0 }
}).then(function(stats) {
// iife.js written
console.log(stats);
});
```
The Node.js module can be used efficiently within a Node.js CMS. IIFE's are cached in memory using [memory-cache](https://github.com/ptarjan/node-cache).
Warning: the generator depends on the free [Google Closure Compiler API](https://developers.google.com/closure/compiler/docs/api-ref) 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.