bu-navigation.php

<?php
/*
Plugin Name: BU Navigation
Plugin URI: http://developer.bu.edu/bu-navigation/
Author: Boston University (IS&T)
Author URI: http://sites.bu.edu/web/
Description: Provides alternative navigation elements designed for blogs with large page counts
Version: 1.2.1
Text Domain: bu-navigation
Domain Path: /languages
*/

/**
Copyright 2012 by Boston University

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.

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

**/

/*
@author Niall Kavanagh <ntk@bu.edu>
@author Gregory Cornelius <gcorne@gmail.com>
@author Mike Burns <mgburns@bu.edu>
@author Tyler Wiest <jtwiest@gmail.com>
*/

// Absolute server path to this plugin dir and file for use by included files
define( 'BU_NAV_PLUGIN', __FILE__ );
define( 'BU_NAV_PLUGIN_DIR', dirname( __FILE__ ) );

// Primary navigation max items to display per level
define( 'BU_NAVIGATION_PRIMARY_MAX', 6 );

// Primary navigation maxium depth
define( 'BU_NAVIGATION_PRIMARY_DEPTH', 1 );

require_once BU_NAV_PLUGIN_DIR . '/includes/settings.php';
require_once BU_NAV_PLUGIN_DIR . '/includes/library.php';
require_once BU_NAV_PLUGIN_DIR . '/includes/class-tree-view.php';
require_once BU_NAV_PLUGIN_DIR . '/includes/class-reorder.php';

class BU_Navigation_Plugin {

	// Admin object
	public $admin;

	// Plugin settings
	public $settings;

	const VERSION = '1.2.1';

	public function __construct() {

		$this->settings = new BU_Navigation_Settings( $this );

		$this->register_hooks();

	}

	/**
	 * Attach WordPress hook callbacks
	 */
	public function register_hooks() {

		add_action( 'plugins_loaded', array( $this, 'add_cache_groups' ) );
		add_action( 'init', array( $this, 'init' ), 1 );

	}

	public function add_cache_groups() {
		if ( function_exists( 'wp_cache_add_non_persistent_groups' ) ) {
			wp_cache_add_non_persistent_groups( array( 'bu-navigation' ) );
		}
	}

	/**
	 * Initialization function for navigation plugin
	 *
	 * @hook init
	 * @return void
	 */
	public function init() {

		load_plugin_textdomain( 'bu-navigation', false, plugin_basename( dirname( __FILE__ ) ) . '/languages/' );

		$this->load_extras();

		if( is_admin() ) {
			$this->load_admin();
		}

		if ( $this->supports( 'widget' ) )
			$this->load_widget();

		do_action('bu_navigation_init');

	}

	public function load_admin() {

		require_once(dirname(__FILE__) . '/admin/admin.php');
		$this->admin = new BU_Navigation_Admin( $this );

	}

	/**
	 * Initializes navigation widgets
	 * @return void
	 */
	public function load_widget() {

		if ( !is_blog_installed() )
			return;

		require_once(dirname(__FILE__) . '/bu-navigation-widget.php'); // Content navigation widget
		register_widget('BU_Widget_Pages');

	}

	/**
	 * Loads plugins for this... plugin
	 * Any .php file placed in the extras directory will be automatically loaded.
	 * @return void
	 */
	public function load_extras() {

		$pattern = sprintf('%s/extras/*.php', BU_NAV_PLUGIN_DIR);

		$files = glob($pattern);

		if ((is_array($files)) && (count($files) > 0)) {
			foreach ($files as $filename) {
				@include_once($filename);
			}
		}

	}

	/**
	 * Navigation plugin features
	 *
	 * @todo discuss these open source defaults with BU
	 *
	 * The navigation plugin is configurable in a few different regards.  This function returns an associative array
	 * of features, with the key representing the feature name and the value holding the default.
	 *
	 * bu-navigation-manager (on by default)
	 * 	- turn on or off the navigation management interfaces ("Edit Order" pages, "Navigation Attributes" metabox)
	 *
	 * bu-navigation-widget (on by default)
	 * 	- turn on or off the "Content Navigation" widget (on by default)
	 *
	 * bu-navigation-primary (off by default -- theme authors, use add_theme_support( 'bu-navigation-primary' ))
	 *  - turn on or off the "Primary Navigation" appearance menu item
	 *
	 * bu-navigation-links
	 *  - turn on or off the external link feature, include with 'page' post type nav menus (on by default)
	 */
	public function features() {

		return array(
			'manager' => true,
			'widget' => true,
			'links' => true,
			'primary' => false,
			);

	}

	/**
	 * Does the current install or theme support a navigation feature?
	 *
	 * There are two different ways to configure navigation features -- with PHP constants, or through the Theme Features API.
	 *
	 * These work as follows:
	 * 1. Define `BU_NAVIGATION_SUPPORTS_*` constant as true or false in wp-config.php or your theme's functions.php (highest priority)
	 * 2. Call add_theme_support( 'bu-navigation-*' ) within your theme's functions.php file (recommended for theme authors)
	 */
	public function supports( $feature ) {

		$feature = strtolower( $feature );
		$defaults = $this->features();

		if ( ! in_array( $feature, array_keys( $defaults ) ) ) {
			error_log( "[bu-navigation] Unknown feature: $feature" );
			return false;
		}

		$supported_const = 'BU_NAVIGATION_SUPPORTS_' . strtoupper( $feature );

		$disabled = ( defined( $supported_const ) && constant( $supported_const ) == false );
		$supported = ( defined( $supported_const ) && constant( $supported_const ) == true ) || $defaults[$feature];
		$theme_supported = current_theme_supports( 'bu-navigation-' . $feature );

		return ( ! $disabled && ( $supported || $theme_supported ) );

	}

	/**
	 * Gets the supported post_types by the bu-navigation plugin.
	 *
	 * @todo needs-unit-test
	 *
	 * @param boolean $include_link true|false link post_type is something special, so we don't always need it
	 * @param string $output type of output (names|objects)
	 * @return array of post_type strings or objects depending on $output param
	 */
	public function supported_post_types( $include_link = false, $output = 'names' ) {

		$post_types = get_post_types( array( 'show_ui' => true, 'hierarchical' => true ), $output );
		$post_types = apply_filters( 'bu_navigation_post_types', $post_types );

		if ( $this->supports( 'links' ) && $include_link ) {
			if ( 'names' == $output )
				$post_types[ BU_NAVIGATION_LINK_POST_TYPE ] = BU_NAVIGATION_LINK_POST_TYPE;
			else
				$post_types[ BU_NAVIGATION_LINK_POST_TYPE ] = get_post_type_object( BU_NAVIGATION_LINK_POST_TYPE );
		}

		return $post_types;

	}

}

// Instantiate plugin (only once)
if( ! isset( $bu_navigation_plugin ) ) {
	$bu_navigation_plugin = new BU_Navigation_Plugin();
}