felixarntz/plugin-lib

<?php
/**
 * Autoloader file
 *
 * @package Leaves_And_Love\Plugin_Lib
 * @since 1.0.0
 */

if ( ! class_exists( 'Leaves_And_Love_Autoloader' ) ) :

    /**
     * Autoloader class.
     *
     * Contains static methods to load classes.
     *
     * To resolve the path to a class, its namespace's vendor name and project name are
     * checked, and if they are registered, the sub-namespaces are resolved to subdirectory
     * names and the class name itself is resolved to a filename. All underscores are replaced
     * with hyphens and the directory and file names are all lowercase.
     *
     * @since 1.0.0
     */
    final class Leaves_And_Love_Autoloader {
        /**
         * Whether the loader has been initialized.
         *
         * @since 1.0.0
         * @static
         * @var bool
         */
        private static $initialized = false;

        /**
         * Registered autoloader namespaces.
         *
         * @since 1.0.0
         * @static
         * @var array
         */
        private static $namespaces = array();

        /**
         * Registers a namespace for autoloading.
         *
         * @since 1.0.0
         * @static
         *
         * @param string $vendor_name  Vendor name of base namespace.
         * @param string $project_name Project name of base namespace.
         * @param string $basedir      Base directory to load classes from.
         * @return bool True on success, false on failure.
         */
        public static function register_namespace( $vendor_name, $project_name, $basedir ) {
            if ( self::namespace_registered( $vendor_name, $project_name ) ) {
                return false;
            }

            if ( ! self::$initialized ) {
                if ( self::init() ) {
                    self::$initialized = true;
                }
            }

            if ( ! isset( self::$namespaces[ $vendor_name ] ) ) {
                self::$namespaces[ $vendor_name ] = array();
            }

            self::$namespaces[ $vendor_name ][ $project_name ] = trailingslashit( $basedir );

            return true;
        }

        /**
         * Checks whether a namespace is registered.
         *
         * @since 1.0.0
         * @static
         *
         * @param string $vendor_name  Vendor name of base namespace.
         * @param string $project_name Project name of base namespace.
         * @return bool True if the namespace is registered, false otherwise.
         */
        public static function namespace_registered( $vendor_name, $project_name ) {
            if ( ! isset( self::$namespaces[ $vendor_name ] ) ) {
                return false;
            }

            if ( ! isset( self::$namespaces[ $vendor_name ][ $project_name ] ) ) {
                return false;
            }

            return true;
        }

        /**
         * Unregisters a namespace from autoloading.
         *
         * @since 1.0.0
         * @static
         *
         * @param string $vendor_name  Vendor name of base namespace.
         * @param string $project_name Project name of base namespace.
         * @return bool True on success, false on failure.
         */
        public static function unregister_namespace( $vendor_name, $project_name ) {
            if ( ! self::namespace_registered( $vendor_name, $project_name ) ) {
                return false;
            }

            unset( self::$namespaces[ $vendor_name ][ $project_name ] );

            if ( empty( self::$namespaces[ $vendor_name ] ) ) {
                unset( self::$namespaces[ $vendor_name ] );
            }

            return true;
        }

        /**
         * Returns the array of registered namespaces.
         *
         * @since 1.0.0
         * @static
         *
         * @return array Registered namespaces.
         */
        public static function get_registered_namespaces() {
            return self::$namespaces;
        }

        /**
         * Tries to autoload a class.
         *
         * @since 1.0.0
         * @static
         *
         * @param string $class_name Class name.
         * @return bool True on success, false on failure.
         */
        public static function load_class( $class_name ) {
            $parts = explode( '\\', $class_name );

            $vendor_name = array_shift( $parts );
            if ( ! isset( self::$namespaces[ $vendor_name ] ) ) {
                return false;
            }

            $project_name = array_shift( $parts );
            if ( ! isset( self::$namespaces[ $vendor_name ][ $project_name ] ) ) {
                return false;
            }

            $path = self::$namespaces[ $vendor_name ][ $project_name ] . strtolower( str_replace( '_', '-', implode( '/', $parts ) ) ) . '.php';
            if ( ! file_exists( $path ) ) {
                return false;
            }

            require_once $path;

            return true;
        }

        /**
         * Initializes the autoloader.
         *
         * @since 1.0.0
         * @static
         *
         * @return bool True on success, false on failure.
         *
         * @codeCoverageIgnore
         */
        private static function init() {
            if ( ! function_exists( 'spl_autoload_register' ) ) {
                return false;
            }

            spl_autoload_register( array( __CLASS__, 'load_class' ) );

            return true;
        }
    }

endif;