Sortable column containing numeric values for Custom Post Type at WordPress Backend

Question

I have custom post type named Cars.

By default, it is sorted by post publishing date, which is very unusual.

WordPress should have provided option to sort columns containing numeric values. Alas, it's not available, and I am looking for solution for the same. Help is appreciated.

Answer 1

Try

// 1. Register the column
add_filter( 'manage_edit-post_columns', 'price_column_register' );
function price_column_register( $columns ) {
    $columns['price'] = __( 'Price', 'theme' );

    return $columns;
}

// 2. Display the column content
add_action( 'manage_posts_custom_column', 'price_column_display', 10, 2 );
function price_column_display( $column_name, $post_id ) {
    if ( 'price' != $column_name )
        return;

    $price = get_post_meta($post_id, 'price', true);
    if ( !$price )
        $price = '<em>' . __( 'undefined', 'theme' ) . '</em>';

    echo $price;
}

// 3. Register the column as sortable
add_filter( 'manage_edit-post_sortable_columns', 'price_column_register_sortable' );
function price_column_register_sortable( $columns ) {
    $columns['price'] = 'price';

    return $columns;
}

// 4. here is the sorting brain
add_filter( 'request', 'price_column_orderby' );
function price_column_orderby( $vars ) {
    if ( isset( $vars['orderby'] ) && 'price' == $vars['orderby'] ) {
        $vars = array_merge( $vars, array(
            'meta_key' => 'price',
            'orderby' => 'meta_value_num',
            'order' => 'asc'

        ) );
    }

    return $vars;
}