admin-last-pages.php

<?php

/**
 * Plugin Name: Admin Last Pages
 * Plugin URI: https://github.com/jonjennings/admin-last-pages
 * Description: Add the last five pages visited in the admin to a drop downmenu in the admin bar.
 * Version: 0.1
 * Author: Jon Jennings, Flynn O'Connor
 */


/*  Copyright 2013  Jon Jennings, Flynn O'Connor

    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
*/



class Admin_Last_Pages {


	function __construct() {

		// Add our menu to the admin bar
		add_action( 'admin_bar_menu', array( $this, 'add_prev_pages_to_toolbar' ), 999 );

		// Get the admin page title.
		add_filter( 'admin_title', array( $this, 'get_admin_title' ), 10, 2);
        
        // Queue scripts/styles
        add_action( 'wp_enqueue_scripts', array( $this, 'queue_scripts' ) );
        add_action( 'admin_enqueue_scripts', array( $this, 'queue_scripts' ) );
	}


    function queue_scripts() {
        // Load the Font Awesome iconfont
        wp_enqueue_style( 'font-awesome', '//netdna.bootstrapcdn.com/font-awesome/3.2.1/css/font-awesome.css' );
    }

	/**
	 * add_prev_pages_to_toolbar function.
	 *
	 * Loop through array stored in user meta and display previous admin pages visited. 
	 *  
	 * @access public
	 * @param mixed $wp_admin_bar
	 * @return void
	 */
	function add_prev_pages_to_toolbar( $wp_admin_bar ) {

		// meta key is "_previous_pages" 
		$user_new = get_user_meta( get_current_user_id(), '_previous_pages', true );

		// add a parent item
        // TODO: excuse the inlined styles... when things get more complex move these out to a CSS file
		$args = array(
			'id'        => 'previous_pages',
			'title'     => '<i title="' . __( 'Previous Pages', 'admin-last-pages' ) . '" style="font-family: FontAwesome; font-size: 21px;" class="icon-compass"></i>',
			'parent'    => 'top-secondary',
		);

		$wp_admin_bar->add_node( $args );

		foreach( $user_new as $test_page ) {

			// add a child item to our parent item
			$args = array(
				'id'      => 'prev_page_' . $test_page['title'],
				'title'   => $test_page['title'],
				'href'    => $test_page['url'],
				'parent'  => 'previous_pages'
			);
			$wp_admin_bar->add_node( $args );

		}
	}
	
	/**
	 * get_admin_title function.
	 *
	 * Get admin page title or if post get post title. 
	 * 
	 * @access public
	 * @param mixed $admin_title
	 * @param mixed $title
	 * @return void
	 */
	function get_admin_title( $admin_title, $title ) {
		$limit = 5;
		$user_id = get_current_user_id();

		//current url
		$the_url = $_SERVER['REQUEST_URI'];
		//delete_user_meta( $user_id, '_previous_pages' );

		$user_last = get_user_meta( $user_id, '_previous_pages', true );
		//print_r($user_last); 

		// any update page or any other page that requires a nonce we don't want to save. 
		if( isset($_GET['_wpnonce']) )
			return; 
		
		// Don't search page array if array doesn't exist (ie first time here)
		if ( ! empty( $user_last ) ) {
			
			// check if url and title are both already in array.
			if ( self::in_array_r( $the_url, $user_last )  && self::in_array_r( $title, $user_last ) )
				return;
			
			// check if on post edit page. 
			if( isset( $_GET['post'] ) ) {
	
				// loop through saved pages, if current post id is already in the array don't save it. 
				foreach($user_last as $page){
						
					if( $page['type'] == 'post' && $page['id'] ==  $_GET['post'])
						return;
	
				}

			}
			
			//check if on taxonomy edit page
			if( isset($_GET['taxonomy']) && isset($_GET['action'])  ){

				// loop through saved pages, if current taxonomy id is already in the array don't save it. 				
				foreach($user_last as $page){
					
					if($page['type'] == 'taxonomy' && $page['id'] == $_GET['tag_ID'])
						return; 
				
				}

			}			
		}

		if( isset( $_GET['post'] ) ) {
			
			// post hasn't been previously been saved, get the post title. 
			$current_page_title = get_the_title( $_GET['post'] );
			$new_entry = array( 'title' => $current_page_title, 'url' => $the_url, 'id' => $_GET['post'], 'type' => 'post' );

		}elseif( isset($_GET['taxonomy']) && isset($_GET['action']) ){
			// if taxonomy term hasn't previously been saved, get the term name. 
			$term = get_term( $_GET['tag_ID'], $_GET['taxonomy'] );
			$new_entry = array( 'title' => $title .' - '. $term->name, 'url' => $the_url, 'id' => $_GET['tag_ID'], 'type' => 'taxonomy' );

			
		}else {
			$new_entry = array( 'title' => $title, 'url' => $the_url );
		}


		// if the array is empty array_unshift won't work so we simply add a new array.
		if ( ! empty( $user_last ) ) {
			array_unshift( $user_last, $new_entry );
		} else {
			$user_last[] = $new_entry; 
		}

		//limit the number of previous pages we list to 5. @todo: functionality to let user set limit. 
		$page_count = count( $user_last );

		// any pages over the limit are unset. 
		if ( $page_count > $limit ) {
			for ( $i = 5 ; $i <= $page_count; $i++ ) {
				unset( $user_last[ $i ] );
			}
		}
		
		update_user_meta( $user_id, '_previous_pages', $user_last );

		return;
	}


	
	/**
	 * in_array_r function.
	 * 
	 * look for a value in a multi-dimensional array. 
	 * Found here: http://stackoverflow.com/questions/4128323/in-array-and-multidimensional-array
	 *
	 * @access private
	 * @static
	 * @param mixed $needle
	 * @param mixed $haystack
	 * @param bool $strict (default: false)
	 * @return void
	 */
	private static function in_array_r( $needle, $haystack, $strict = false) {
		foreach ( $haystack as $item ) {
			if ( ( $strict ? $item === $needle : $item == $needle ) || ( is_array( $item ) && self::in_array_r( $needle, $item, $strict ) ) ) {
				return true;
			}
		}

		return false;
	}
}

// Instantiate ourselves
$admin_last_pages = new Admin_Last_Pages();
?>