Title and post URL based on custom fields?

Question

I have custom fields in my custom post type. They should serve as a title and post slug for URL. Basically, whenever I change the content of the custom fields, the title field should react accordingly. E.g. if the field NAME contains 'John' and the SURNAME 'Smith', the title should transform to 'John Smith'.

The users of the site will be unexperienced so they won't understand the need of putting NAME and SURNAME and a separate title for that - that's why I need it.

I know I can display custom field content instead of a title in my template, but that's not the same. I also need the permalink to be amended accordingly.

So, to recap My input: custom field NAME = John custom field SURNAME = Smith What should happen: post title = John Smith permalink = john-smith (I presume it will process the title extracted from the custom fields as it would normally do)

I hope it's clear now. Thanks indeed for any suggestions.

Answer 1

I think a good way to do what you want is hook the wp_insert_post_data filter. Here you can change the title and slug of the post before it is saved to database:

add_filter( 'wp_insert_post_data', 'wpse_update_post_title_and_slug' );
function wpse_update_post_title_and_slug( $data ) {

    //You can make some checks here before modify the post data.
    //For example, limit the changes to standard post type
    if( 'post' == $data['post_type'] ) {

        //Add post meta to post title
        $data['post_title'] = $_POST['the-name-field'] . ' ' . $_POST['the-surname-field'];

        //Update the slug of the post for the URL
        $data['post_name'] = sanitize_title( $data['post_title'] );

    }

    return $data;

}

Answer 2

There is an alternative, don't set the title at all. Instead, filter it.

Here is the_title filter as demonstrated by the codex:

function suppress_if_blurb($title, $id) {
    if (in_category('blurb', $id)) {
        return '';
    }
    return $title;
}
add_filter('the_title', 'suppress_if_blurb', 10, 2);

If instead we did something like this:

function wpse144041_modify_title($title, $id) {
    if ( get_post_type( $id ) == 'yourposttype' ) {
        $first = get_post_meta( $id, 'first', true );
        $last = get_post_meta( $id, 'last', true );
        $title = $first.' '.$last;
    }
    return $title;
}
add_filter('the_title', 'wpse144041_modify_title', 10, 2);

Then the title field is now irrelevant, and will show the first and last names as the title on the front end for your post type. Adjust the relevant field and post type names to match

Answer 3

I'm afraid the code above didn't work at all. I modified it like that:

add_filter( 'wp_insert_post_data', 'wpse_update_post_title_and_slug' );
function wpse_update_post_title_and_slug( $data , $postarr ) {

    //You can make some checks here before modify the post data.
    //For example, limit the changes to standard post type
    if( 'people' == $data['post_type'] ) {

        //Add post meta to post title
        $data['post_title'] = $_POST['first_name'] . ' ' . $_POST['last_name'];

        //Update the slug of the post for the URL
        $data['post_name'] = sanitize_title( $data['post_title'] );

    }

    return $data;

}

Despite the fact that the particular custom fields are present and have content, neither the title nor the slug changes.

I assumed that both would be amended "by force" upon saving the post? Or maybe it doesn't work that way?

I also tried to re-code it like this:

function wpse_update_post_title_and_slug( $data , $postarr ) {

if( $data['post_type'] == 'people' ) {
// get post data
$id = $postarr['ID'];
$first_name = get_post_meta( $id, 'first_name', true );
$last_name = get_post_meta( $id, 'last_name', true );
// insert the data into the title and the slug
$data['post_title'] = $first_name . ' ' . $last_name;
$data['post_name'] = sanitize_title( $data['post_title'] );
    }

    return $data;

}
add_filter( 'wp_insert_post_data', 'wpse_update_post_title_and_slug' );

But it's all the same. No reaction, no error, no nothing. As it was totally absent from functions.php. It works ordinarily.