You’re right to use ‘save_post’ action hook.
Try this:
<?php
add_action('save_post', 'some_function');
function some_function($post_id)
{
if(get_post_type($post_id) != "VA_LISTING_PTYPE")
return;
$meta_value = get_post_meta( $post_id, 'featured-cat', true );
if($meta_value != 1)
return;
update_post_meta($post_id, 'website', '');
update_post_meta($post_id, 'twitter', '');
update_post_meta($post_id, 'facebook', '');
}
if you’re on WordPress 3.7 or higher, you can use it this way:
add_action('save_post_VA_LISTING_PTYPE', 'some_function');
function some_function($post_id)
{
$meta_value = get_post_meta( $post_id, 'featured-cat', true );
if($meta_value != 1)
return;
update_post_meta($post_id, 'website', '');
update_post_meta($post_id, 'twitter', '');
update_post_meta($post_id, 'facebook', '');
}
I hope it work with you.