Replacing the title of a post with a custom taxonomy on wordpress

Question

Using filters/hooks, how would I replace the title of a wordpress post with whatever term has been selected from a custom taxonomy.

Hopefully the attached image will explain what I'm trying to do.

Let's say I selected 'Powerchrono' - I would like the title of the post to be replaced with the selected term, and it's parent.

Any help would be much appreciated.

I'd obviously like the url of the post to also be updated too.

Answer 1

I can't guarantee this will work straight out of the gate since it's untested. But this should get you started:

functions.php

<?php
add_action('save_post', 'update_term_title');
function update_term_title($post_id)
{
    if(defined('DOING_AUTOSAVE') && DOING_AUTOSAVE) 
        return;
    if(!current_user_can('edit_post', $post_id))
        return;

    //Replace 'manufacturer' with whatever your custom taxonomy slug is
    $terms = wp_get_post_terms($post_id, 'manufacturer');

    if(empty($terms))
        return;

    $title = false;
    foreach($terms as $term)
    {
        if($term->parent)
        {
            $parent = get_term($term->parent, 'manufacturer');
            $title = $term->name.' '.$parent->name;
            break;
        }
    }
    /*Default to first selected term name if no children were found*/
    $title = $title ? $title : $terms[0]->name;

    /*We must disable this hook and reenable from within
    if we don't want to get caught in a loop*/
    remove_action('save_post', 'update_term_title');
    $update = array(
        'ID'=>$post_id,
        'post_name'=>sanitize_title_with_dashes($title),
        'post_title'=>$title
    );
    wp_update_post($update);
    add_action('save_post', 'update_term_title');
}
?>