Group with better-include demo

register-meta-box.php

<?php
global $meta_boxes;
$meta_boxes = array();

$meta_boxes[] = array(
	'title' => 'Pedigree',
	'only_on'    => array(
		'id'       => array( 1 ), // Show only on "Hello World" post
	),
	'fields' => array(
		array(
	    	'id' => 'group',
	    	'type' => 'group',
	        'name' => 'Group',
	        'clone' => true,
	        'fields' => array(
	        	array(
	                'name' => 'Year',
	                'id' => 'year',
	                'type' => 'text',
	                'columns' => 2,
	            ),
	            array(
	                'name' => 'Title',
	                'id' => 'title',
	                'type' => 'text',
	                'columns' => 10,
	            ),
	            array(
	                'name' => 'Wins',
	                'id' => 'wins',
	                'type' => 'text',
	                'columns' => 4,
	            ),
	            array(
	                'name' => 'Podiums',
	                'id' => 'podiums',
	                'type' => 'text',
	                'columns' => 4,
	            ),
	            array(
	                'name' => 'Poles',
	                'id' => 'poles',
	                'type' => 'text',
	                'columns' => 4,
	            ),
	            array(
	                'name' => 'Description',
	                'id' => 'description',
	                'type' => 'textarea',
	                'columns' => 12,
	            ),
	        ),
	    ),
	)
);

/**
 * Register meta boxes
 *
 * @return void
 */
function prefix_register_meta_boxes()
{
	global $meta_boxes;
	// Make sure there's no errors when the plugin is deactivated or during upgrade
	if ( class_exists( 'RW_Meta_Box' ) )
	{
		foreach ( $meta_boxes as $meta_box )
		{
			if ( isset( $meta_box['only_on'] ) && ! rw_maybe_include( $meta_box['only_on'] ) )
			{
				continue;
			}
			new RW_Meta_Box( $meta_box );
		}
	}
}
add_action( 'admin_init', 'prefix_register_meta_boxes' );

/**
 * Check if meta boxes is included
 *
 * @return bool
 */
function rw_maybe_include( $conditions ) {
	// Include in back-end only
	if ( ! defined( 'WP_ADMIN' ) || ! WP_ADMIN ) {
		return false;
	}
	// Always include for ajax
	if ( defined( 'DOING_AJAX' ) && DOING_AJAX ) {
		return true;
	}
	if ( isset( $_GET['post'] ) ) {
		$post_id = intval( $_GET['post'] );
	}
	elseif ( isset( $_POST['post_ID'] ) ) {
		$post_id = intval( $_POST['post_ID'] );
	}
	else {
		$post_id = false;
	}
	$post_id = (int) $post_id;
	$post    = get_post( $post_id );
	foreach ( $conditions as $cond => $v ) {
		// Catch non-arrays too
		if ( ! is_array( $v ) ) {
			$v = array( $v );
		}
		switch ( $cond ) {
			case 'id':
				if ( in_array( $post_id, $v ) ) {
					return true;
				}
			break;
			case 'parent':
				$post_parent = $post->post_parent;
				if ( in_array( $post_parent, $v ) ) {
					return true;
				}
			break;
			case 'slug':
				$post_slug = $post->post_name;
				if ( in_array( $post_slug, $v ) ) {
					return true;
				}
			break;
			case 'category': //post must be saved or published first
				$categories = get_the_category( $post->ID );
				$catslugs = array();
				foreach ( $categories as $category )
				{
					array_push( $catslugs, $category->slug );
				}
				if ( array_intersect( $catslugs, $v ) )
				{
					return true;
				}
			break;
			case 'template':
				$template = get_post_meta( $post_id, '_wp_page_template', true );
				if ( in_array( $template, $v ) )
				{
					return true;
				}
			break;
		}
	}
	// If no condition matched
	return false;
}