Complete and simple to install Composer autoloader or Magento
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Magento Composer Autoloader

Complete and simple to install Composer autoloader or Magento

Why Does This Even Exist?

  1. Other Composer autoloader integrations aren't complete. The most common issues with other implementations:
    • They allow both Magento and Composer to register autoloaders. This causes problems when using libraries that expect class_exists to work properly—Magento's will always attempt to include the file.
    • They allow Magento's autoload to register itself, then manually de-register it. This is wholly unnecessary overhead.
    • They require manual configuration of composer.json for Magento autoloading.
  2. With more and more need to integrate namespaced systems with Magento, a require-able, redistributable, easy to set up module is needed


Until it's listed in packagist or firegento, add the repository to your composer.json:

    "type": "vcs",
    "url": ""

Add the library to your require section:

"require": {
    "mattwellss/magento-composer-autoloader": "~1.0"


Post install, the new Varien_Autoload class needs to know where vendor/autoload.php is hiding. This must be configured.

Defining the vendor root directory

Regardless of how the vendor dir is defined, it must not end with a trailing slash.

The two methods of describing the vendor root directory are:

  • VENDOR_ROOT constant. Must be defined in all entry points.
  • MAGE_VENDOR_ROOT env variable. Be sure it's defined for all PHP environments (cli and fpm/mod_php).

Optimizing the Autoloader

Normally, composer dump -o is all one does to optimize a composer autoloader. However, running php shell/classmap_generator.php when deploying new code to production is recommended. The script generates a classmap file to be used by composer to speed autoloading of files in Magento's code pools.

To enable use of the generated classmap, include define('OPTIMIZED_COMPOSER', true) in includes/config.php.