autoloader.php

<?php
/**
 * Autoload for stuff
 */

/**
 * Needs to be a minimum of 5.4.0 for namespaces and new array format
 */
if (version_compare(PHP_VERSION, '5.4.0', '<')) {
	throw new Exception('The Skiddle SDK requires PHP version 5.4 or higher.');
}

/**
 * Load SDK classes, PSR style
 * https://github.com/php-fig/fig-standards/blob/master/accepted/PSR-4-autoloader-examples.md
 */
spl_autoload_register(function ($class) {
	// project-specific namespace prefix
	$prefix = 'SkiddleSDK\\';

	// base directory for the namespace prefix
	$baseDir = __DIR__ . '/src/';

	// does the class use the namespace prefix?
	$len = strlen($prefix);
	if (strncmp($prefix, $class, $len) !== 0) {
		// no, move to the next registered autoloader
		return;
	}

	// get the relative class name
	$relativeClass = substr($class, $len);

	// replace the namespace prefix with the base directory, replace namespace
	// separators with directory separators in the relative class name, append
	// with .php
	$file = rtrim($baseDir, '/') . '/' . str_replace('\\', '/', $relativeClass) . '.php';
	// if the file exists, require it
	if (file_exists($file)) {
		require $file;
	}
});