Slim Framework and Composer Autoload

There is a specific configuration in composer.json which deals with autoloading of the classes. Its not necessary to do autoloading, one can do it manually as always.

require '../src/controllers/AppController.php';

This way, one has to do it all the time for each individual classes. The autoloading of classes does this automatically depending upon the settings and some conventions. Depending upon the folder structure and the namespaces, the setting could just be as below.

{
    "require": {
        "slim/slim": "^3.12"
    },
    "autoload": {
        "psr-4": { "rain\\" : ["src/"] }
    }
}

Here we are talking about psr-4 standards. There are different standards in psr and they may have somethings in common. However there are differences between them also. So just keep this in mind we are talking about psr-4 standards here.

"autoload": {
        "psr-4": { "rain\\" : ["src/"] }
    }

Well, now let’s look at the standards of psr-4 and how it finds the files.

• Composer will load the files relative to composer.json file. In the setting above, it will load from the folder src which is at the same level as composer.json
• The first setting rain in the autoload configuration is the namespace of the PHP Classes
• PHP class file name and the class name should be exactly the same (except the .php extension)
• PHP class file location and its namespace should exactly the same
• PHP class namespace should be exactly the same as specified in the autoload configuration

A PHP class file for the above settings would look like below.

//location: src/configs/AppConfig.php

namespace rain\configs;

class AppConfig
{
    function getConfig()
    {
        return 'AppConfig';
    }
}

Once one is careful enough to map the folder structure and namespace the composer autoload functionality will load the classes. Here is a nice explanation of the concepts.

After adding the autoload field in composer.json, one has to re-run dump-autoload to re-generate the vendor/autoload.php file.

This should takecare of autoloading of the class files. The dump-autoload is a critical step while updating the composer.json.

For windows

php composer.phar dump-autoload

For Unix, Linux and macOS

php composer dump-autoload

Happy coding.