class-wrc-autoloader.php

<?php
/**
 * WRC Autoloader
 *
 * Uses spl_autoload to include and make all /inc/ classes available on demand
 *
 * @since 0.8
 */
if ( ! defined( 'ABSPATH' ) ) {
	exit;
}


class WRC_Autoloader {

	/**
	 * Path to the includes directory.
	 *
	 * @var string
	 */
	private $include_path = '';

	/**
	 * The Constructor.
	 */
	public function __construct() {
		if ( function_exists( '__autoload' ) ) {
			spl_autoload_register( '__autoload' );
		}

		spl_autoload_register( array( $this, 'autoload' ) );

		/**
		 * Load everything in the /inc/ directory
		 */
		$this->include_path = untrailingslashit( plugin_dir_path( __FILE__ ) ) . '/inc/';
	}

	/**
	 * Auto-load classes on demand to reduce memory consumption.
	 *
	 * @param string $class
	 */
	public function autoload( $class ) {
		$class = strtolower( $class );
		$file  = $this->get_file_name_from_class( $class );

		$this->load_file( $this->include_path . $file );
	}

	/**
	 * Take a class name and turn it into a file name.
	 *
	 * @param  string $class
	 *
	 * @return string
	 */
	private function get_file_name_from_class( $class ) {
		return 'class-' . str_replace( '_', '-', $class ) . '.php';
	}

	/**
	 * Include a class file.
	 *
	 * @param  string $path
	 *
	 * @return bool successful or not
	 */
	private function load_file( $path ) {
		if ( $path && is_readable( $path ) ) {
			include_once( $path );

			return true;
		}

		return false;
	}
}

new WRC_Autoloader();