Show different page templates for custom post types

Question

I am using the Custom Post Type UI plugin for worpdress and have created custom "pages". I have set these pages to be able to use the page template dropdown but would like to know if anyone knows of a way to show separate page templates for different post types?

Answer 1

You will need the theme_page_templates filter hook to remove the templates that you do not want to see for each post type. When the templates are loaded, including for display in the edit screen the templates that are returned are first passed to this function:

apply_filters ( 'theme_page_templates', array $page_templates, WP_Theme $this, WP_Post|null $post )

To implement you will use something like the following code:

function filter_theme_page_templates( $templates, $theme, $post ){
    // make sure we have a post so we know what to filter
    if ( !empty( $post ) ){

        // get the post type for the current post
        $post_type = get_post_type( $post->ID );

        // switch on the post type
        switch( $post_type ){
            case 'custom-post-type':
                // remove anything we don't want shown for the custom post type
                // array is keyed on the template filename
                unset( $templates['page-template-filename.php'] );
                break;
            default:
                // if there is no match it will return everything
                break;
        }
    }

    // return the (maybe) filtered array of templates
    return $templates;
}
add_filter( 'theme_page_templates', 'filter_theme_page_templates', 10, 3 );