The Basics

Autoloading

Composer will generate an autoload.php file in the /vendor directory after each installation or update. By including this single file, you’ll be able to access all classes provided by your installed libraries.

Looking at a Laravel project, you’ll see that the public/index.php file in the application root (which handles all incoming requests) requires the autoloader, which then makes all required libraries usable within the scope of your application. This includes Laravel’s first-party Illuminate components as well as any required third party packages.

Laravel's public/index.php file:

public/index.php

<?php

define('LARAVEL_START', microtime(true));

require __DIR__.'/../vendor/autoload.php';

// additional bootstrapping methods...

Directory Structure

In general (and by convention), a package contains a src/ (short for “source”) folder containing all package specific logic (classes) and a composer.json file containing information about the package itself. Additionally, most packages also include a license and documentation.

If we look at the general directory structure of a generic package, you’ll notice how it looks quite different from a standard Laravel project.

- src
- tests
CHANGELOG.md
README.md
LICENSE
composer.json

In a package, all code that would ordinarily live in the app/ directory of a Laravel application will live in the src/ directory of your package.