Added initial abstract factory.

abstract-factory/post-logger/post-logger.php

@@ -0,0 +1,101 @@
+<?php
+/*
+Plugin Name: Post Logger
+Description: Logs when post is updated (Abstract factory design pattern example).
+Version: 0.1.0
+Author: Akeda Bagus
+Author URI: http://gedex.web.id/
+Plugin URI: http://github.com/gedex/WP_DPP
+*/
+
+namespace WP_DPP\Post_Logger;
+
+
+interface Abstract_Factory {
+	public static function get_instance();
+	public static function get_loggers();
+	public static function set_loggers();
+}
+
+
+class Factory {
+	/**
+	 * Logger products
+	 *
+	 * @var array
+	 */
+	private static $loggers;
+
+	public static function get_instance( $logger ) {
+		$classname = 'WP_DPP\Post_Logger\Logger_' . ucfirst( strtolower( $logger ) );
+		if ( in_array( $logger, self::$products ) && class_exists( $classname ) ) {
+			return new $classname;
+		}
+
+		throw new Exception( 'Undefined Logger ' . $logger );
+	}
+
+	public static function set_loggers(array $loggers) {
+		self::$loggers = $loggers;
+	}
+
+	public static function get_loggers() {
+		return self::$loggers;
+	}
+}
+
+
+interface Logger {
+	public function do_logging(\WP_Post $post);
+}
+
+
+class Logger_File implements Logger {
+	public function do_logging(\WP_Post $post) {
+		error_log( sprintf( 'Logger message for post "%s."', $post->post_title ) );
+	}
+}
+
+
+class Logger_Email implements Logger {
+	public function do_logging(\WP_Post $post) {
+		extract( array(
+			'to'      => 'admin@gedex.web.id',
+			'subject' => 'Logger subject',
+			'message' => 'Logger message for post ' . $post->post_title,
+		) );
+		wp_mail( $to, $subject, $message );
+	}
+}
+
+
+/**
+ * Class that bootstrap the plugin
+ */
+class WP_Plugin {
+
+	public function __construct() {
+		Factory::set_products( array('file', 'email') );
+
+		add_action( 'save_post', array( $this, 'logger_in_action' ) );
+	}
+
+	public function logger_in_action( $post_id ) {
+		if ( ! wp_is_post_revision( $post_id ) )
+			return;
+
+		foreach ( Factory::get_loggers() as $logger ) {
+			try {
+				$instance = Factory::get_instance( $logger );
+				$instance->do_logging( get_post( $post_id ) );
+			} catch (\Exception $e) {
+				error_log( $e->getMessage() );
+			}
+		}
+	}
+
+}
+
+add_action( 'plugins_loaded', function() {
+	new WP_Plugin();
+} );