l3rady-cpt-structure-helper.php

<?php
/*
Plugin Name: l3rady's CPT Structure Helper
Plugin URI: http://l3rady.com/projects/l3rady-cpt-structure-helper/
Description: 
Author: Scott Cariss
Version: 0.2.1
Author URI: http://l3rady.com/
Text Domain: sccptshelper
Domain Path: /languages
*/

/*  Copyright 2012  Scott Cariss  (email : scott@l3rady.com)

    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
*/

Class l3radyCPTStructureHelper
{
    private static $registered_cpt = array();

    public static function init()
    {
        add_filter( "page_css_class", array( __CLASS__, "add_active_to_list_pages_for_CPTs" ), 5, 10 );
        add_filter( "wp_get_nav_menu_items", array( __CLASS__, "add_active_to_menus_for_CPTs" ), 3, 10 );
        add_action( 'admin_init', array( __CLASS__, 'add_cpt_reading_settings' ) );
    }


    public static function  add_active_to_list_pages_for_CPTs( $css_class, $page, $depth, $args, $current_page )
    {
        if( ! $page_id = self::work_out_local_page() )
            return $css_class;

        if( ! isset( $page_id ) )
            return $css_class;

        static $ancestors;

        if( ! isset( $ancestors ) )
            $ancestors = (array) get_post_ancestors( $page_id );

        if( $page->ID == $page_id )
            $css_class[] = "current_page_item";

        if( $page->ID == end( $ancestors ) )
            $css_class[] = "current_page_parent";

        if( in_array( $page->ID, $ancestors ) )
            $css_class[] = "current_page_ancestor";

        return $css_class;
    }


    public static function add_active_to_menus_for_CPTs( $items, $menu, $args )
    {
        if( ! $page_id = self::work_out_local_page() )
            return $items;

        static $ancestors;

        if( ! isset( $ancestors ) )
            $ancestors = (array) get_post_ancestors( $page_id );

        foreach( $items as $key => $item )
        {

            if( $item->object_id == $page_id )
                $items[ $key ]->classes = array_merge( $items[ $key ]->classes, array( "current-menu-item", "current_page_item" ) );

            if( $item->object_id == end( $ancestors ) )
                $items[ $key ]->classes = array_merge( $items[ $key ]->classes, array( "current-menu-parent", "current_page_parent" ) );

            if( in_array( $item->object_id, $ancestors ) )
                $items[ $key ]->classes = array_merge( $items[ $key ]->classes, array( "current-menu-ancestor", "current_page_ancestor" ) );
        }

        return $items;
    }

    
    public static function work_out_local_page()
    {
        if( ! ( is_single() || is_archive() || is_home() ) )
            return false;

        $settings = self::get_cpt_settings();

        $post_type = get_post_type();

        if( ! isset( $settings[$post_type] ) )
            return false;
        else
            return $settings[$post_type];
    }


    public static function get_cpt_settings(  )
    {
        $settings = get_option("sc_cpt_sh_permalinks");
        $show_on_front = get_option( 'show_on_front' );
        $page_for_posts = get_option( 'page_for_posts' );

        if( "page" == $show_on_front && ! empty( $page_for_posts ) )
            $settings['post'] = $page_for_posts;

        return $settings;
    }


    /*
     * Wrapper for register_post_type(). Use register_post_type_with_page_select() as if you were using
     * register_post_type() but if this functions finds a setting to link the CPT to a page then it will adjust
     * the slug accordingly. Could do with some enhancement that would allow for more complex structures E.G differences
     * between slug and archive.
     */
    public static function register_post_type_with_page_select( $post_type, $args )
    {
        // Get settings that hold links between CPT and page.
        $settings = get_option("sc_cpt_sh_permalinks");

        // Check if setting exists? If yes then adjust slug accordingly.
        if( ! empty( $settings[ $post_type ] ) )
            $args['rewrite']['slug'] = self::work_out_cpt_slug_from_page_id( $settings[ $post_type ], $args['rewrite']['slug'] );

        self::$registered_cpt[ $post_type ] = ( isset( $args['label'] ) ) ? $args['label'] : $args['labels']['name'];

        // Register post type the normal way
        register_post_type( $post_type, $args );
    }


    /*
     * Takes ID of a page and works out the full slug of the page including the page hierarchy. E.G. media-centre/news
     * If page cannot be found then return $post_type as fallback.
     */
    public static function work_out_cpt_slug_from_page_id( $id, $post_type )
    {
        // Get permalink of selected page ID
        $permalink_of_page = get_permalink( $id );

        // If fail to get permalink then fall back to using CPT slug
        if( ! $permalink_of_page )
            return $post_type;

        // Return slug of page including the page hierarchy
        return ltrim( rtrim( str_replace( home_url(), "", $permalink_of_page ), '/' ), '/' );
    }


    /*
     * Adds to the reading settings page in admin. Will only show settings if some CPTs where registered using
     * register_post_type_with_page_select();
     */
    public static function add_cpt_reading_settings()
    {
        if( empty( self::$registered_cpt ) )
            return;

        register_setting("reading", "sc_cpt_sh_permalinks", array( __CLASS__, "validate_cpt_reading_settings" ) );
        add_settings_section("sc_cpt_sh_cpt_reading", __("CPT Reading Settings", "sccptshelper"), array( __CLASS__, "cpt_reading_settings_description" ), "reading");
        add_settings_field("sc_cpt_sh_cpt_reading_roots", __("CPT Root Pages", "sccptshelper"), array( __CLASS__, "cpt_reading_settings_roots" ), "reading", "sc_cpt_sh_cpt_reading");
    }


    /*
     * Validates settings for CPT Seading Settings
     */
    public static function validate_cpt_reading_settings( $input )
    {
        $input = array_map( "intval", $input ); // Make sure all values are integer
        $input = array_filter( $input, array( __CLASS__, "filter_empty" ) ); // Remove all entries that are empty()

        return $input;
    }


    /*
     * Used in array_filter(). Used to remove all key/values that are empty()
     */
    public static function filter_empty( $val )
    {
        return ! empty( $val );
    }


    public static function cpt_reading_settings_description()
    {
        echo "Some description to be added at a later date";
    }


    public static function cpt_reading_settings_roots()
    {
        $settings = get_option("sc_cpt_sh_permalinks");

        foreach( self::$registered_cpt as $cpt_slug => $cpt_name)
        {
            echo "<p><label>Page for " . $cpt_name . ": ";
            wp_dropdown_pages(
                array(
                     'name' => 'sc_cpt_sh_permalinks[' . $cpt_slug . ']',
                     'echo' => 1,
                     'show_option_none' => __( '&mdash; Select &mdash;' ),
                     'option_none_value' => '0',
                     'selected' => $settings[ $cpt_slug ]
                )
            );
            echo "</label></p>";
        }
    }
}

l3radyCPTStructureHelper::init();


/*
 * API
 */
function sc_cpt_sh_register_post_type( $post_type = '', $args = array() )
{
    l3radyCPTStructureHelper::register_post_type_with_page_select( $post_type, $args );
}
function sc_work_out_local_page()
{
    return l3radyCPTStructureHelper::work_out_local_page();
}