event-hooks.md

Event Hooks

• Run a Function Before Webpack Compiles
• Run a Function After Webpack Compiles

Run a Function Before Webpack Compiles

In some scenarios, you may need to execute a piece of logic before your compilation begins. Perhaps you need to copy a directory or move a file. The mix.before() function allows for this.

mix.before(() => {
    console.log('I will be logged before the compilation begins.');
});

If the logic you're executing is asynchronous, be sure to return a Promise from your callback function, like so:

mix.before(stats => {
    return new Promise(
        resolve => setTimeout(resolve, 2000)
    );
});

Mix will not begin its compilation until all before hooks have fully resolved. As such, for this example the compilation would begin after two seconds.

Run a Function After Webpack Compiles

If, on the other hand, you need to execute a piece of logic after webpack has completed its compilation, reach for the mix.after() method - or its alias, mix.then().

mix.js('src/app.js', 'dist')
   .after(stats => {
       // webpack compilation has completed
   });

This callback function will be passed a webpack Stats object. As an example, let's log a list of all compiled assets.

mix.js('resources/assets/js/app.js', 'public/js').then(stats => {
    console.log(Object.keys(stats.compilation.assets));
});

The official documentation for the Stats object may be found here.