PSR4 Composer Autoloading namespaces

Question

I've been having a little play around with some Composer autoloading and i'm getting some issues so the directory structure is

index.php
app/
   helpers/
          router.php
vendor/
   composer/
          /*usual files*/
   autoload.php

Inside my composer.json I have the following

"autoload": {
        "psr-4": {
            "App\\": "app/"
        }
    }

Inside my index.php I have

<?php
// Autoload our namespaces
require __DIR__.'/vendor/autoload.php';

use App\Helpers\Router;
$route = new Router;

Getting the following error

Fatal error: Class 'App\Helpers\Router' not found in /var/www/public/index.php on line 6

I have tried a few different things to try and get it working but i'm unsure where i'm going wrong. This is my first time looking into autoloading using Composer outside of a framework so would appreciate any guidance.

Answer 1

PSR-4 is case sensitive. The structure has to be app/Helpers/Router.php or better App with capital A.

All class names MUST be referenced in a case-sensitive fashion.

The subdirectory name MUST match the case of the sub-namespace names.

The terminating class name corresponds to a file name ending in .php. The file name MUST match the case of the terminating class name.

http://www.php-fig.org/psr/psr-4/