Autoloading

Autoloading is a concept in PHP where you specific a directory or directories to load classes from. This is much more beneficial than using require or include to load classes. It is also a requirement for using Composer packages.

By default any Flight class is autoloaded for your automatically thanks to composer. However, if you want to autoload your own classes, you can use the Flight::path method to specify a directory to load classes from.

Basic Example

Let's assume we have a directory tree like the following:

# Example path
/home/user/project/my-flight-project/
├── app
│   ├── cache
│   ├── config
│   ├── controllers - contains the controllers for this project
│   ├── translations
│   ├── UTILS - contains classes for just this application (this is all caps on purpose for an example later)
│   └── views
└── public
    └── css
    └── js
    └── index.php

You may have noticed that this is the same file structure as this documentation site.

You can specify each directory to load from like this:

/**
 * public/index.php
 */

// Add a path to the autoloader
Flight::path(__DIR__.'/../app/controllers/');
Flight::path(__DIR__.'/../app/utils/');

/**
 * app/controllers/MyController.php
 */

// no namespacing required

// All autoloaded classes are recommended to be Pascal Case (each word capitalized, no spaces)
// As of 3.7.2, you can use Pascal_Snake_Case for your class names by running Loader::setV2ClassLoading(false);
class MyController {

    public function index() {
        // do something
    }
}

Namespaces

If you do have namespaces, it actually becomes very easy to implement this. You should use the Flight::path() method to specify the root directory (not the document root or public/ folder) of your application.

/**
 * public/index.php
 */

// Add a path to the autoloader
Flight::path(__DIR__.'/../');

Now this is what your controller might look like. Look at the example below, but pay attention to the comments for important information.

/**
 * app/controllers/MyController.php
 */

// namespaces are required
// namespaces are the same as the directory structure
// namespaces must follow the same case as the directory structure
// namespaces and directories cannot have any underscores (unless Loader::setV2ClassLoading(false) is set)
namespace app\controllers;

// All autoloaded classes are recommended to be Pascal Case (each word capitalized, no spaces)
// As of 3.7.2, you can use Pascal_Snake_Case for your class names by running Loader::setV2ClassLoading(false);
class MyController {

    public function index() {
        // do something
    }
}

And if you wanted to autoload a class in your utils directory, you would do basically the same thing:

/**
 * app/UTILS/ArrayHelperUtil.php
 */

// namespace must match the directory structure and case (note the UTILS directory is all caps
//     like in the file tree above)
namespace app\UTILS;

class ArrayHelperUtil {

    public function changeArrayCase(array $array) {
        // do something
    }
}

Underscores in Class Names

As of 3.7.2, you can use Pascal_Snake_Case for your class names by running Loader::setV2ClassLoading(false);. This will allow you to use underscores in your class names. This is not recommended, but it is available for those who need it.

/**
 * public/index.php
 */

// Add a path to the autoloader
Flight::path(__DIR__.'/../app/controllers/');
Flight::path(__DIR__.'/../app/utils/');
Loader::setV2ClassLoading(false);

/**
 * app/controllers/My_Controller.php
 */

// no namespacing required

class My_Controller {

    public function index() {
        // do something
    }
}