Dashboard User Password Generator demo plugin main file

master.php

<?php
/*
Plugin Name: Dashboard User Password Generator
Plugin URI: http://nabeel.molham.me/blog/plugins/user-password-generator-demo
Description: Add a generator button next password field in the dashboard
Version: 1.0
Author: Nabeel Molham
Author URI: http://nabeel.molham.me/
Text Domain: user-password-generator-demo
Domain Path: /languages
License: GNU General Public License, version 2, http://www.gnu.org/licenses/gpl-2.0.html
*/

// Exit if accessed directly
// عشان لو حد نده على النلف مباشر يوقفه
if ( ! defined( 'ABSPATH' ) )
	die();

/**
 * Constants
 * شوية حاجات بعرفها اساسية بتستخدم على طول
 */
// Plugin Matser file
define( 'UPGD_MAIN_FILE', __FILE__ );
// Physical path of the plugin on server hard drive
define( 'UPGD_DIR', plugin_dir_path( UPGD_MAIN_FILE ) );
// URL to the plugin directory
define( 'UPGD_URI', plugin_dir_url( UPGD_MAIN_FILE ) );
// Text domain unique name used for localizaion
define( 'UPGD_DOMAIN', 'user-password-generator-demo' );
// The plugin current version 
define( 'UPGD_VERSION', '1.0' );

/**
 * User Password Generator plugin Main
 * 
 * @class User_Password_Generator_Demo
 * @version	1.0
 */
class User_Password_Generator_Demo
{
	/**
	 * Plugin Version
	 * 
	 * @var string
	 */
	public $version = '1.0.0';

	/**
	 * @var User_Password_Generator_Demo The single instance of the class
	 * @since 1.0
	 */
	protected static $_instance = null;

	/**
	 * Constructor
	 * 
	 * @since 1.0
	 * 
	 * @return User_Password_Generator_Demo
	 */
	public function __construct()
	{
		// load language files
		add_action( 'plugins_loaded', array( &$this, 'load_language' ) );
	}

	/**
	 * Language file loading
	 * 
	 * @since 1.0
	 * 
	 * @return void
	 */
	public function load_language()
	{
		// language files located in the "languages" directory in the plugin
		// if the current language files not found it will use the default string written in the plugin
		load_plugin_textdomain( UPGD_DOMAIN, false, UPGD_DIR . 'languages/' );
	}

	/**
	 * Main User_Password_Generator_Demo Instance
	 *
	 * Ensures only one instance of User_Password_Generator_Demo is loaded or can be loaded.
	 *
	 * @since 1.0
	 * @static
	 * @see UPGP()
	 * 
	 * @return User_Password_Generator_Demo - Main instance
	 */
	public static function instance() 
	{
		if ( is_null( self::$_instance ) )
			self::$_instance = new self();

		return self::$_instance;
	}
}

/**
 * Returns the main instance of the plugin to prevent the need to use globals.
 *
 * @since  1.0
 * 
 * @return User_Password_Generator_Demo
 */
function UPGP()
{
	return User_Password_Generator_Demo::instance();
}

// startup plugin
$GLOBALS['user_password_generator_demo'] = UPGP();