WordPress-Plugin-Boilerplate/plugin-name/class-plugin-name.php

<?php
/**
 * Plugin Name.
 *
 * @package   Plugin_Name
 * @author    Your Name <email@example.com>
 * @license   GPL-2.0+
 * @link      http://example.com
 * @copyright 2013 Your Name or Company Name
 */

/**
 * Plugin class.
 *
 * TODO: Rename this class to a proper name for your plugin.
 *
 * @package Plugin_Name
 * @author  Your Name <email@example.com>
 */
class Plugin_Name {

	/**
	 * Plugin version, used for cache-busting of style and script file references.
	 *
	 * @since   1.0.0
	 *
	 * @var     string
	 */
	const VERSION = '1.0.0';

	/**
	 * Unique identifier for your plugin.
	 *
	 * The variable name is used as the text domain when internationalizing strings of text.
	 * Its value should match the Text Domain file header in the main plugin file.
	 *
	 * @since    1.0.0
	 *
	 * @var      string
	 */
	protected $plugin_slug = 'plugin-name';

	/**
	 * Return the plugin slug.
	 *
	 * @since    1.0.0
	 */
	public function get_plugin_slug() {
		return $this->plugin_slug;
	}

	/**
	 * Instance of this class.
	 *
	 * @since    1.0.0
	 *
	 * @var      object
	 */
	protected static $instance = null;

	/**
	 * Initialize the plugin by setting localization and loading public scripts and styles.
	 *
	 * @since     1.0.0
	 */
	private function __construct() {

		// Load plugin text domain
		add_action( 'init', array( $this, 'load_plugin_textdomain' ) );

		// Activate plugin when new blog is added
		add_action( 'wpmu_new_blog', array( $this, 'activate_new_site' ) );

		// Load public-facing style sheet and JavaScript.
		add_action( 'wp_enqueue_scripts', array( $this, 'enqueue_styles' ) );
		add_action( 'wp_enqueue_scripts', array( $this, 'enqueue_scripts' ) );

		// Define custom functionality. Read more about actions and filters: http://codex.wordpress.org/Plugin_API#Hooks.2C_Actions_and_Filters
		add_action( 'TODO', array( $this, 'action_method_name' ) );
		add_filter( 'TODO', array( $this, 'filter_method_name' ) );

	}

	/**
	 * Return an instance of this class.
	 *
	 * @since     1.0.0
	 *
	 * @return    object    A single instance of this class.
	 */
	public static function get_instance() {

		// If the single instance hasn't been set, set it now.
		if ( null == self::$instance ) {
			self::$instance = new self;
		}

		return self::$instance;
	}

	/**
	 * Fired when the plugin is activated.
	 *
	 * @since    1.0.0
	 *
	 * @param    boolean    $network_wide    True if WPMU superadmin uses "Network Activate" action, false if WPMU is disabled or plugin is activated on an individual blog.
	 */
	public static function activate( $network_wide ) {
		if ( function_exists( 'is_multisite' ) && is_multisite() ) {
			if ( $network_wide  ) {
				// Get all blog ids
				$blog_ids = self::get_blog_ids();

				foreach ( $blog_ids as $blog_id ) {
					switch_to_blog( $blog_id );
					self::single_activate();
				}
				restore_current_blog();
			} else {
				self::single_activate();
			}
		} else {
			self::single_activate();
		}
	}

	/**
	 * Fired when the plugin is deactivated.
	 *
	 * @since    1.0.0
	 *
	 * @param    boolean    $network_wide    True if WPMU superadmin uses "Network Deactivate" action, false if WPMU is disabled or plugin is deactivated on an individual blog.
	 */
	public static function deactivate( $network_wide ) {
		if ( function_exists( 'is_multisite' ) && is_multisite() ) {
			if ( $network_wide ) {
				// Get all blog ids
				$blog_ids = self::get_blog_ids();

				foreach ( $blog_ids as $blog_id ) {
					switch_to_blog( $blog_id );
					self::single_deactivate();
				}
				restore_current_blog();
			} else {
				self::single_deactivate();
			}
		} else {
			self::single_deactivate();
		}
	}

	/**
	 * Fired when a new site is activated with a WPMU environment.
	 *
	 * @since    1.0.0
	 *
	 * @param    int    $blog_id ID of the new blog.
	 */
	public function activate_new_site( $blog_id ) {
		if ( 1 !== did_action( 'wpmu_new_blog' ) )
			return;

		switch_to_blog( $blog_id );
		self::single_activate();
		restore_current_blog();
	}

	/**
	 * Get all blog ids of blogs in the current network that are:
	 * - not archived
	 * - not spam
	 * - not deleted
	 *
	 * @since    1.0.0
	 *
	 * @return   array|false    The blog ids, false if no matches.
	 */
	private static function get_blog_ids() {
		global $wpdb;

		// get an array of blog ids
		$sql = "SELECT blog_id FROM $wpdb->blogs
			WHERE archived = '0' AND spam = '0'
			AND deleted = '0'";
		return $wpdb->get_col( $sql );
	}

	/**
	 * Fired for each blog when the plugin is activated.
	 *
	 * @since    1.0.0
	 */
	private static function single_activate() {
		// TODO: Define activation functionality here
	}

	/**
	 * Fired for each blog when the plugin is deactivated.
	 *
	 * @since    1.0.0
	 */
	private static function single_deactivate() {
		// TODO: Define deactivation functionality here
	}

	/**
	 * Load the plugin text domain for translation.
	 *
	 * @since    1.0.0
	 */
	public function load_plugin_textdomain() {

		$domain = $this->plugin_slug;
		$locale = apply_filters( 'plugin_locale', get_locale(), $domain );

		load_textdomain( $domain, trailingslashit( WP_LANG_DIR ) . $domain . '/' . $domain . '-' . $locale . '.mo' );
		load_plugin_textdomain( $domain, FALSE, basename( dirname( __FILE__ ) ) . '/languages' );
	}

	/**
	 * Register and enqueue public-facing style sheet.
	 *
	 * @since    1.0.0
	 */
	public function enqueue_styles() {
		wp_enqueue_style( $this->plugin_slug . '-plugin-styles', plugins_url( 'css/public.css', __FILE__ ), array(), self::VERSION );
	}

	/**
	 * Register and enqueues public-facing JavaScript files.
	 *
	 * @since    1.0.0
	 */
	public function enqueue_scripts() {
		wp_enqueue_script( $this->plugin_slug . '-plugin-script', plugins_url( 'js/public.js', __FILE__ ), array( 'jquery' ), self::VERSION );
	}

	/**
	 * NOTE:  Actions are points in the execution of a page or process
	 *        lifecycle that WordPress fires.
	 *
	 *        WordPress Actions: http://codex.wordpress.org/Plugin_API#Actions
	 *        Action Reference:  http://codex.wordpress.org/Plugin_API/Action_Reference
	 *
	 * @since    1.0.0
	 */
	public function action_method_name() {
		// TODO: Define your action hook callback here
	}

	/**
	 * NOTE:  Filters are points of execution in which WordPress modifies data
	 *        before saving it or sending it to the browser.
	 *
	 *        WordPress Filters: http://codex.wordpress.org/Plugin_API#Filters
	 *        Filter Reference:  http://codex.wordpress.org/Plugin_API/Filter_Reference
	 *
	 * @since    1.0.0
	 */
	public function filter_method_name() {
		// TODO: Define your filter hook callback here
	}

}