Modifying WP_Title For Custom Post Type

Question

Trying to modify the output of the WP_Title through a custom post type with a filter. I've had no issues doing it to the_title but I assume as the wp_title function is called through the header it's the problem and I'm missing something simple.

What I want to do is change the output of the listing pages with some of the meta-box data into the pages title tag. What I've set up so far is as follows:

add_filter('wp_title', 'dw_listing_title', 10, 2);
function dw_listing_title($title, $id) {

if('sp_property' == get_post_type($id) )
    $address = get_post_meta($id, 'Address', false );
    $city = get_post_meta($id, 'City', false );
    $listingID = get_post_meta($id,"ListingId");

    $title = $address[0] . ', ' . $city[0] . ' Listing: ' . $listingID[0];

return $title;
}

This alters the title just fine when I switch wp_title to the_title. I think I need to add a global variable to tie into it but when I tried adding global $post (or $wp_query) nothing changed.

Also Im not sure if Yoast SEO would cause problems with trying to change this? I dont have any data entered into the input boxes though.

EDIT:: So after turning off the Yoast SEO plugin the wp_title is being rewritten, the problem now is the meta box values being displayed.

Answer 1

The filter wp_title won't pass $id to your function. Drop the parameter and instead retrieve it with get_queried_object_id():

function dw_listing_title( $title ) {
    if ( is_singular() && $id = get_queried_object_id() ) {
       // Modify $title as required
    }

    return $title;
}