Magento Composer Autoloader

Complete and simple to install Composer autoloader or Magento, _(*1)

Why Does This Even Exist?

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.
With more and more need to integrate namespaced systems with Magento, a require-able, redistributable, easy to set up module is needed

Installation

Until it's listed in packagist or firegento, add the repository to your composer.json:, _(*2)

{
    "type": "vcs",
    "url": "https://github.com/mattwellss/magento-composer-autoloader"
}

Add the library to your require section:, _(*3)

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

Configuration

Post install, the new Varien_Autoload class needs to know where vendor/autoload.php is hiding. This must be configured., _(*4)

Defining the vendor root directory

Regardless of how the vendor dir is defined, it must not end with a trailing slash., _(*5)

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)., _(*6)

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., _(*7)

To enable use of the generated classmap, include define('OPTIMIZED_COMPOSER', true) in includes/config.php., _(*8)