plugin-boilerplate.php

<?php
/*
Plugin Name: Plugin Boilerplate
Plugin URI: http://URI_Of_Page_Describing_Plugin_and_Updates
Description: Boilerplate for WordPress plugins containing basic functionality.
Version: 1.0
Author: Rickard Andersson, Mikael Jorhult, Emil Österlund
Author URI: http://URI_Of_The_Plugin_Author
License: A "Slug" license name e.g. GPL, GPL2, MIT
	
	Copyright YEAR  PLUGIN_AUTHOR_NAME  (email : PLUGIN AUTHOR EMAIL)

	This program is free software; you can redistribute it and/or modify
	it under the terms of the GNU General Public License, version 2, as 
	published by the Free Software Foundation.
	
	This program is distributed in the hope that it will be useful,
	but WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
	GNU General Public License for more details.
	
	You should have received a copy of the GNU General Public License
	along with this program; if not, write to the Free Software
	Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
*/

// Uncomment this if you want to use the widget boilerplate
// require_once('widgets/my-widget.php');

/**
 * This is where you add comments for your plugin class 
 * @author Your Name <your@name.tld>
 * @todo Add your name here
 * @todo Change class name to something more appropriate 
 */
class WP_Plugin_Boilerplate {
	/**
	 * This value will be used for 
	 * - the gettext text domain
	 * - the sub-folder when adding scripts and styles
	 * - the handle for scripts and styles
	 * Please make sure that this value corresponds to the folder name where your plugin resides.
	 * @var string 
	 * @todo Change this value to your plugin name
	 */
	private $plugin_name = "plugin_boilerplate";
		
	/**
	 * The constructor is executed when the class is instatiated and the plugin gets loaded.
	 */
	function __construct() {
		// Uncomment any of these calls to add the functionality that you need.

		//add_action('init', array($this, 'init_custom_post_types'), 20);
		//add_action('init', array($this, 'init_localization'), 20);
		//add_action('init', array($this, 'init_scripts'), 20);
		//add_action('init', array($this, 'init_styles'), 20);
		//add_action('init', array($this, 'init_shortcodes'), 20);
		//add_action('admin_menu', array($this,'init_admin_menu'));
	}
	
	/**
	 * This function is executed when the plugin is activated. To activate it just uncomment
	 * the line at the bottom of this file with the register_activation_hook( ... ) function 
	 * @return void
	 */
	static function install() {
		// Uncomment this if you need database tables.
		//self::install_db();
		
		// Perform your activation tasks in here. 
	}
	
	/**
	 * This function is executed from install( ) and is used if you need database tables.
	 * @return void
	 */
	static function install_db() {
	    global $wpdb;
	    
		/**
		 * This value represent the current version of the layout of the database tables. This value
		 * needs to be increased every time you change something in your database layout. 
		 * @var integer
		 */
		$db_version = 1;

	    /**
	     * To create tables, dbDelta from wp-admin/includes/upgrade.php is needed
	     */
	    require_once(ABSPATH . 'wp-admin/includes/upgrade.php');

	    /**
	     * @todo Change myplugin to your plugin name
	     */
        $option_name = 'myplugin-db-version';
        $current_version = null;
        $current_version = get_option($option_name);
	    
	    // Check if the latest version is already installed
	    if($current_version == $db_version) {
	    	return;
	    }
	    
	    // In this example two tables is defined, 'table1' and 'table2'. This example tries
	    // to illustrate how the tables gets upgraded. The layout of the tables is currently at 
	    // version three and two upgrade routines are defined for upgrading the tables from the
	    // first and second version. Note that the changes in the database layout needs to be added
	    // to the $structure[ ] array _and_ to the $upgrade[ ] array. $structure[ ] is used when the
	    // plugin is installed on a new system and $upgrade[ ] is used for upgrading. 

	    // Define tables
	    $tables = array('table1', 'table2');
	    $structure = array( 
	    
    		// Definition for 'table1' 
	        "(`id` int(11) unsigned NOT NULL auto_increment,
	        `field1` varchar(255) NOT NULL,
	        `field2` varchar(255) NOT NULL,
	        `field3` varchar(255) default NULL,
	        `field4` tinyint(3) unsigned NOT NULL default '0',
	        `field5` timestamp NOT NULL default CURRENT_TIMESTAMP,
	        PRIMARY KEY  (`id`) )",
	     
		    // Definition for 'table2'
	        "(`id` int(11) unsigned NOT NULL auto_increment,
	        `field1` varchar(255) NOT NULL,
	        `field2` varchar(255) NOT NULL,
	        `field3` varchar(255) NOT NULL,
	        PRIMARY KEY(`id`) )"
		);
        $upgrade = array();
	           
        // Routines for upgrading, the structure is
        // $upgrade[ from db version ][ table name ]
        // Routine should include %s for table prefix.
        // Upgrade routines are applied in order from current version to the newer version. Routines for upgrading
        // only has to be defined once.
          
		// Example of an upgrade routine which will add two fields to table1 when the plugin gets upgraded from
		// DB version 1 to a later version.		
		$upgrade[1] = array("table1" => "ALTER TABLE %stable1 ADD `field3` varchar(255) default NULL, ADD `field4` tinyint(3) unsigned NOT NULL default '0'");
	    
		// Example of an upgrade routine which will add one field to table1 and one field to table2 when the plugin
		// gets upgraded from DB version 2 to a later version. 
		$upgrade[2] = array("table1" => "ALTER TABLE %stable1 ADD `field5` timestamp NOT NULL default CURRENT_TIMESTAMP", "table2" => "ALTER TABLE %stable2 ADD `field3` varchar(255) NOT NULL" );

		// Iterate tables and create them
		foreach ($tables as $key => $table) {
			if($wpdb->get_var(sprintf("SHOW TABLES LIKE '%s%s'", $wpdb->prefix, $table)) != $wpdb->prefix . $table) {
				// Table doesn't exist, create it.
				 
				$sql = sprintf("CREATE TABLE %s%s %s DEFAULT CHARSET=utf8", $wpdb->prefix, $table, $structure[$key]);
				dbDelta($sql);
			} else {
				// Table exists, check if there's any upgrade routines defined.
				// The upgrade routines are applied in order from previous to current version

				for ($i = $current_version; $i < $db_version; $i++) {
					if (strlen($upgrade[ $i ][ $table ]) > 0) {
						$sql = sprintf($upgrade[ $i ][ $table ], $wpdb->prefix);
						$wpdb->query($sql);
					}
				}
			}
		}
		 
		if ($current_version === false) {
			add_option($option_name, $db_version);
		} else {
			update_option($option_name, $db_version);
		}
	}
	
	/**
	 * Loading the gettext textdomain first from the WP languages directory, 
	 * and if that fails try the subfolder /languages/ in the plugin directory. 
	 * @return void
	 */
	function init_localization() {
		if(!load_plugin_textdomain($this->plugin_name, '/wp-content/languages/')) {
			load_plugin_textdomain($this->plugin_name, '/wp-content/plugins/' . $this->plugin_name . '/languages/');
		}
	}
	
	/**
	 * Loading the javascripts, first using jquery using the CDN and then the file 
	 * /scripts/script.js from the plugin directory. By default the script is enqueued 
	 * in the page footer for faster page loading. 
	 * @return void
	 */
	function init_scripts() {
		// Only enqueue scripts on frontend. 
		if(!is_admin()) {
			// Only enqueue the script if it actually exists. 
			if(file_exists(dirname(__FILE__) . '/scripts/script.js')) {
				if(function_exists('plugins_url')) {
					wp_enqueue_script($this->plugin_name . '-script', plugins_url('/scripts/script.js', __FILE__), array('jquery'), '1.0', true);
				} else {
					wp_enqueue_script($this->plugin_name . '-script', WP_PLUGIN_URL . '/' . $this->plugin_name . '/scripts/script.js', array('jquery'), '1.0', true);
				}
			}
		}
	}
	
	/**
	 * Loading the stylesheet for this plugin. 
	 * @return void
	 */
	function init_styles() {
		// Only enqueue styles on frontend and if the stylesheet actually exists. 
		if(!is_admin() && file_exists(dirname(__FILE__) . '/styles/style.css')) {
			if(function_exists('plugins_url')) {
				wp_enqueue_style($this->plugin_name . '-stylesheet', plugins_url('/styles/style.css', __FILE__), array(), '1.0', 'all');
			} else {
				wp_enqueue_style($this->plugin_name . '-stylesheet', WP_PLUGIN_URL . '/' . $this->plugin_name . '/styles/styles.css', array(), '1.0', 'all');
			}
		}
	}
	
	/**
	 * Add a shortcode for this plugin. It's recommended to change the code
	 * to prevent from collisions. (The second value in the array)
	 * @return void
	 */
	function init_shortcodes() {
		add_shortcode('shortcode', array($this, 'plugin_boilerplate_shortcode'));
	}
	
	/**
	 * This function will be executed when the plugin shortcode is used in a page 
	 * or post. This is where you put the code to be executed
	 * @param array $atts
     * @param string $contents
     * @return string
	 */
	function plugin_boilerplate_shortcode($atts, $contents = '') {
		// Extracting all the values sent as arguments with this shortcode
		extract(shortcode_atts(array(
			'attribute' => 'default',
		), $atts));
		
		// It's recommended to use output buffering to catch the contents and then return it.
		ob_start();
		
		// Perform the tasks of this function in here, and echo everything that you want to
		// output to the browser.
		
		// Fetch the output that you just echoed, and put it into the $content variable.
		$content = ob_get_clean();
		
		// Remember to always RETURN the content from the shortcode function, otherwise
		// the result won't be placed in the correct part of the page. 
		return $content;
	}
	
	/**
	 * Loading custom post types and taxonomies for this plugin. 
	 * @return void
	 */
	function init_custom_post_types() {
		// Register post_type as custom post type with post_type taxonomy as a taxonomy
		register_post_type('post_type', array(
			'labels' => array(
				'name' => __('Post Types', 'plugin-boilerplate'),
				'singular_name' => 'Post type',
				'add_new' => 'Add new',
				'add_new_item' => 'Add new post type',
				'edit_item' => 'Edit post type',
				'new_item' => 'New post type',
				'view_item' => 'Show post type',
				'search_items' => 'Search post type',
				'not_found' =>  'Not found',
				'not_found_in_trash' => 'No post type was found in trash',
				'parent_item_colon' => 'Parent:'
			),
			'public' => true,
			'exclude_from_search' => true,
			'query_var' => true,
			'rewrite' => true,
			'capability_type' => 'post',
			'hierarchical' => false,
			'show_in_nav_menus' => false,
			'menu_position' => null,
			'supports' => array('title', 'editor', 'author', 'thumbnail', 'excerpt', 'comments')
		));
		
		register_taxonomy('post_type_taxonomy', 'taxonomy', array(
			'hierarchical' => true,
			'labels' => array(
				'name' => 'Taxonomies',
				'singular_name' => 'Taxonomy',
				'search_items' => 'Search taxonomy',
				'all_items' => 'All taxonomies',
				'parent_item' => 'Parent taxonomy',
				'parent_item_colon' => 'Parent taxonoy:',
				'edit_item' => 'Edit taxonomy',
				'update_item' => 'Update taxonomy',
				'add_new_item' => 'Add new taxonomy',
				'new_item_name' => 'Taxonomy name',
				'menu_name' => 'Taxonomies',
			),
			'show_ui' => true,
			'query_var' => true,
			'rewrite' => array('slug' => 'taxonomy')
		));
	}
	
	/**
	 * Adds a new menu with the name "My Admin Menu" and let's anyone that
	 * can publish posts be able to use it. 
	 * @return void
	 */
	function init_admin_menu() {
		// Add the menu page
		add_menu_page('Plugin Boilerplate Admin Menu', 'BP menu', 'publish_posts', $this->plugin_name . '-admin-menu', array($this,'main_menu_page'));

		// Also let's add a submenu
		add_submenu_page($this->plugin_name . '-admin-menu', 'Plugin Boilerplate Sub-Menu', 'BP submenu', 'publish_posts', $this->plugin_name . '-admin-submenu', array($this, 'sub_menu_page'));
	}

	/**
	 * This function will be executed when the admin page is to be loaded
	 * @return void
	 */
	function main_menu_page() {
		// Include the HTML from a separate file to keep the plugin class clean
		require "pages/admin_main.php";
	}

	/**
	 * This function will be executed when the admin sub page is to be loaded
	 * @return void
	 */
	function sub_menu_page() {
		// Include the HTML from a separate file to keep the plugin class clean
		require "pages/admin_options_page.php";
	}
}

/**
 * Register the plugin
 * @todo Change 'Plugin_Boilerplate' in the anonymous function to the name of the class
 */
add_action("init", create_function('', 'new WP_Plugin_Boilerplate();'));


// Uncomment this if you need an install routine, remember to change the class name. 
//register_activation_hook(__FILE__, array('WP_Plugin_Boilerplate', 'install'));

// Ending PHP tag is not needed, it will only increase the risk of white space 
// being sent to the browser before any HTTP headers.