PHP Autoloading with Composer using Namespaces

Question

I previously had a pretty simple autoload script working nicely, but as I've noticed that Doctrine2 is using Composer for this, I thought it might be nice to streamline everything. Unfortunately, Composer does not seem to be working as I understood it to.

Here is the relevant part of my composer.json

"autoload": {
    "psr-0": {
       "": "models/",
       "Catalog2\\Config": "class/"
    }
}

Note that the "": "models/" line used by Doctrine2 has been working just fine. After I ran composer update , the bottom part of my vendor/composer/autoload_namespaces.php looks like so:

'Doctrine\\Common\\' => array($vendorDir . '/doctrine/common/lib'),
'Catalog2\\Config' => array($baseDir . '/class'),
'' => array($baseDir . '/models'),

So far so good, I think. In my routes.php file (basically a front-controller) I have the following:

<?php
use Catalog2\Config;

//autoload classes
require_once __DIR__.'/vendor/autoload.php';

try {
    $router = new Router;
} catch(Exception $e ) {
    echo "<strong>Can't create router object</strong><br/>";
}

Here Catalog2\Config\Router should be calling my class/Router.php, which begins as follows:

<?php
namespace Catalog2\Config;

class Router {
    protected $resource; //what are we manipulating? A product? An order?
    protected $action; //what are we doing with that resource?

When I go to the page I get this:

Fatal error: Class 'Router' not found in /home/tom/Code/productCatalog2/routes.php on line 14

What is going wrong here? I repeat that Doctrine2 was able to autoload my model code from /models, so why aren't my changes working?

Answer 1

According to PSR-0 the namespace prefix will be included to the path.

So the complete filename for your class must be:

class/Catalog2/Config/Router.php

Meanwhile PSR-4 would behave like you expected: it will just match the namespace prefix and will not append it additionally to the given path.

References:

• https://getcomposer.org/doc/04-schema.md#autoload

PS: you probably want the namespace prefix to be "Catalog2\\Config\\" (see the trailing slash)