Why is Composer not loading a PSR-4 autoload?

Question

I'm trying to use the composer vimeo package "vimeo/vimeo-api": "dev-master".

Things get ugly in composers own ClassLoader.php, in the function below it gets as far as: if (0 === strpos($class, $prefix)) and breaks out of the loop because at this point $class = 'Vimeo' and $prefix = 'Vimeo/' so the result is false.

private function findFileWithExtension($class, $ext)
{
    // PSR-4 lookup
    $logicalPathPsr4 = strtr($class, '\\', DIRECTORY_SEPARATOR) . $ext;

    $first = $class[0];
    if (isset($this->prefixLengthsPsr4[$first])) {
        foreach ($this->prefixLengthsPsr4[$first] as $prefix => $length) {
            if (0 === strpos($class, $prefix)) {
                foreach ($this->prefixDirsPsr4[$prefix] as $dir) {
                    if (file_exists($file = $dir . DIRECTORY_SEPARATOR . substr($logicalPathPsr4, $length))) {
                        return $file;
                    }
                }
            }
        }
    }
    ...

The composer.json file that is inside the vimeo package declares a psr-4 autoload of 'Vimeo\' as follows:

{
    "name": "vimeo/vimeo-api",
    "description": "Official PHP library for the Vimeo API.",
    "homepage": "https://github.com/vimeo/vimeo.php",
    "keywords": ["vimeo", "video"],
    "license": "Apache-2.0",
    "authors": [
        {
            "name": "Vimeo",
            "homepage": "http://vimeo.com"
        }
    ],
    "minimum-stability": "dev",
    "require": {
        "php": ">=5.3.0"
    },
    "autoload": {
        "psr-4": {
            "Vimeo\\": "src/Vimeo"
        }
    }
}

The composer created autoload_psr4.php is as follows:

<?php

// autoload_psr4.php @generated by Composer

$vendorDir = dirname(dirname(__FILE__));
$baseDir = dirname($vendorDir);

return array(
    'Vimeo\\' => array($vendorDir . '/vimeo/vimeo-api/src/Vimeo')
);

So when I come to instantiate the class 'new Vimeo('arg','arg');' I get a class not found error.

Could it be something to do with the fact I am running inside of the Zendframework (1.12.8), or composer messing up or something?

I am unsure why you are skimming these files, why not use the vendor/autoload.php ? — Ronni Skansing
Yes I am using vendor/autoload.php but as it failed to load the class I dug into the code to see where it fails. — Owen

Owen Owen · Accepted Answer · 2014-09-08T12:15:32

Right. A colleague found the solutions: we need to prefix the namespace that composer has used when we instantiate the composer-managed class. So new Vimeo\Vimeo($foo, $bar) works, or putting use Vimeo\Video before making an instance new Vimeo($foo, $bar).

Why is Composer not loading a PSR-4 autoload?

1 Answers