gistfile1.php

<?php
/**
 * @package Custom post type relation test
 * @version 0.1
 */
/*
Plugin Name: Custom post type relation test
Plugin URI: http://wordpress.org/#
Description: Custom post type relation test
Author: Laurent Dinclaux <lox.dev@knc.nc>
Version: 0.1
Author URI: http://www.knc.nc
*/


function cptr_init() {
	/* registers post type */
	$args = new ArrayObject(array(), ArrayObject::ARRAY_AS_PROPS);
	
	$args->label = 'Movie';
	$args->public = true;
	$args->supports = explode(',', 'title,editor,excerpt,page-attributes');
	register_post_type( 'movie', (array)$args );
	
	$args->label = 'Actor';
	register_post_type( 'actor', (array)$args );
	
	/* registers taxonomy */
	$args = new ArrayObject(array(), ArrayObject::ARRAY_AS_PROPS);
	$args->label = 'Actors';
	
	register_taxonomy('actors',array('movie', 'actor'), (array)$args );
	
}
add_action( 'init', 'cptr_init', 0 );

function cptr_post_updated ($post_ID, $post, $post_before) {
	
	if($post->post_type !== 'actor') return;
	
	// status changes
	if($post->post_status !== $post_before->post_status) {
		if($post->post_status === 'publish') {
			wp_set_object_terms($post->ID, $post->post_title, 'actors');
		}
		else {

			if($term =  get_term_by( 'name', $post->post_title, 'actors' ) ) {
					wp_delete_term($term->term_id, 'actors');
			}
						
		}
	}
	
	elseif($post->post_status === 'publish') {
			
		if( $post->post_title !== $post_before->post_title
			|| $post->post_name !== $post_before->post_name) {
				
				$term =  get_term_by( 'name', $post_before->post_title, 'actors' );
				
			if( $term ) {
				wp_update_term($term->term_id, 'actors', array('slug'=>$post->post_name, 'name'=>$post->post_title));
			}
		}
		
	}
	
}


add_action('post_updated', 'cptr_post_updated',10 ,3);