Demonstrates how to add a meta box to a custom post type created by the framework and display the set custom field value in the front end article page and a custom cloumn in the post listing table. This is a sample plugin introduced in the tutorial Add a Meta Box to a Custom Post Type (http://en.michaeluno.jp/admin-page-framework/tutorials-v3/13…

tutorials-13 -add-a-meta-box-to-a-framework-custom-post-type.php

<?php
/**
 *  Plugin Name:    Admin Page Framework Tutorial 13 - Add a Meta Box to a Custom Post Type
 *  Plugin URI:     http://en.michaeluno.jp/admin-page-framework
 *  Description:    Adds a meta box to custom post type created by the framework and display the set custom field value.
 *  Author:         Michael Uno
 *  Author URI:     http://michaeluno.jp
 *  Version:        1.0.0
 *  Requirements:   PHP 5.2.4 or above, WordPress 3.4 or above. Admin Page Framework 3.0.6 or above
 */

// Include the library file. Set your file path here.
include( dirname( dirname( __FILE__ ) ) . '/library/apf/admin-page-framework.php' );

class APF_Tutorial_PostType extends AdminPageFramework_PostType {
        
    /**
     * Sets up necessary settings.
     */
    public function setUp() {

        $this->setArguments(
            array( // argument - for the array structure, refer to http://codex.wordpress.org/Function_Reference/register_post_type#Arguments
                'labels'            => array(
                    'name'           => __( 'Colors', 'admin-page-framework-turorial' ),
                    'add_new_item'   => __( 'Add Color', 'admin-page-framework-tutorial' ),
                ),
                'supports'          => array( 'title' ), // e.g. array( 'title', 'editor', 'comments', 'thumbnail', 'excerpt' ),
                'public'            => true,
                'menu_icon'         => version_compare( $GLOBALS['wp_version'], '3.8', '>=' ) 
                    ? 'dashicons-welcome-learn-more' 
                    : 'https://lh4.googleusercontent.com/-z7ydw-aPWGc/UwpeB96m5eI/AAAAAAAABjs/Brz6edaUB58/s800/demo04_16x16.png',
                // (framework specific key) this sets the screen icon for the post type for WordPress v3.7.1 or below.
                'screen_icon'       => dirname( APFDEMO_FILE  ) . '/asset/image/wp-logo_32x32.png', // a file path can be passed instead of a url, plugins_url( 'asset/image/wp-logo_32x32.png', APFDEMO_FILE )
            )    
        );    
 
    }
    
    /*
     * Modifies the columns of post listing table.
     * 
     * @remark  columns_{post type slug}
     * @return  array
     */
    public function columns_apf_tutorial_posts( $aHeaderColumns ) {
        
        return array(
                'cb'    => '<input type="checkbox" />', // Checkbox for bulk actions. 
                'title' => __( 'Title', 'admin-page-framework' ), // Post title. Includes "edit", "quick edit", "trash" and "view" links. If $mode (set from $_REQUEST['mode']) is 'excerpt', a post excerpt is included between the title and links.
                'color' => __( 'Color', 'admin-page-framework-tutorial' ),
            )     
            // + $aHeaderColumns // uncomment this to enable the default columns.
        ;
        
    }
    
    /**
     * Modifies the 'color' column cell contents of the post listing table 
     * @return      string
     */
    public function cell_apf_tutorial_posts_color( $sCell, $iPostID ) { // cell_{post type}_{column key}
        
        $_sColor = get_post_meta( $iPostID, 'my_custom_color', true );
        $_sColor = $_sColor ? $_sColor : 'transparent';
        return $sCell
                . '<div class="color-sample-container">'
                    . '<p style="background-color: ' . esc_attr( $_sColor ) . '">'
                    . '</p>'
                . '</div>';
        
    }
    
    /**
     * Modifies the CSS rules of the admin page of the post listing table of the post type of this class.
     * @callback    filter      style_{instantiated class name}
     * @return      string
     */
    public function style_APF_Tutorial_PostType( $sStyle ) {
        
        return $sStyle . "
            .color-sample-container { 
                height: 3em; 
            } 
            .color-sample-container p {
                border: solid 1px #CCC; 
                width: 3em;
                height: 100%;
            }
        ";
    }
    
    /**
     * Modifies the output of the post content.
     * 
     * This method is called in the single page of this class post type.
     * 
     * Alternatively, you may use the 'content_{instantiated class name}' method,
     */
    public function content( $sContent ) { 
                    
        $_sSelectedColor = get_post_meta( $GLOBALS['post']->ID, 'my_custom_color', true );
        $_sSelectedColor = $_sSelectedColor ? $_sSelectedColor : 'transparent';
        return "<h3>" . __( 'Selected Color', 'admin-page-framework-tutorial' ) . "</h3>"         
            . "<div style='width: 100%;'>" 
                . "<div style='margin:auto; width: 3em; height: 3em; background-color:" . $_sSelectedColor . "'></div>"
            . "</div>"
            ;

    }    
    
}

class APF_Tutorial_CustomPostTypeMetaBox extends AdminPageFramework_MetaBox {
    
    /*
     * Use the setUp() method to define settings of this meta box.
     */
    public function setUp() {
    
        /**
         * Adds setting fields in the meta box.
         */
        $this->addSettingFields(
            array(
                'field_id'  => 'my_custom_color',
                'type'      => 'color',
                'title'     => __( 'Color', 'admin-page-framework-tutorial' ),
            )
        );     
    
    }
   
}

new APF_Tutorial_PostType( 'apf_tutorial_posts' );      // the post type slug

new APF_Tutorial_CustomPostTypeMetaBox(
    null,   // meta box ID - can be null.
    __( 'Tutorial - Add a Meta Box to Custom Post Type', 'admin-page-framework-demo' ), // title
    array( 'apf_tutorial_posts' ),                 // post type slugs: post, page, etc.
    'normal',                                      // context
    'low'                                          // priority
);