Hi there,

I’ve used code snippet below to create some custom fields in Woo Orders. I have then used Admin Columns to make these fields appear in the Order Admin page. I want the ‘order_sorting’ field to be filterable, and have checked the Admin Columns settings, however no content appears in the filter box. What can I do to create filterable custom column fields?

Many thanks

// Add columns to admin orders table.
add_filter( 'manage_edit-shop_order_columns', 'set_custom_edit_shop_order_columns' );
function set_custom_edit_shop_order_columns($columns) {
    $columns['shipping_service'] = __( 'Shipping Service', 'woocommerce' );
    $columns['tracking_number'] = __( 'Tracking number', 'woocommerce' );
    $columns['shipping_date'] = __( 'Shipping date', 'woocommerce' );
    $columns['order_sorting'] = __( 'Pre-orders', 'woocommerce' );
    return $columns;
}

// Add the data to the custom columns for the order post type:
add_action( 'manage_shop_order_posts_custom_column' , 'custom_shop_order_column', 10, 2 );
function custom_shop_order_column( $column, $post_id ) {
    switch ( $column ) {

        case 'shipping_service' :
            echo esc_html( get_post_meta( $post_id, 'shipping_service', true ) );
            break;

        case 'tracking_number' :
            echo esc_html( get_post_meta( $post_id, 'tracking_number', true ) );
            break;

        case 'shipping_date' :
            echo esc_html( get_post_meta( $post_id, 'shipping_date', true ) );
            break;
        case 'order_sorting' :
            echo esc_html( get_post_meta( $post_id, 'order_sorting', true ) );
            break;

    }
}

// Add a metabox.
add_action( 'add_meta_boxes', 'add_shop_order_meta_box' );
function add_shop_order_meta_box() {

    add_meta_box(
        'custom_meta_box',
        __( 'Tracking information', 'woocommerce' ),
        'shop_order_content_callback',
        'shop_order'
    );

}

// For displaying metabox content
function shop_order_content_callback( $post ) {

    $shipping_service = get_post_meta( $post->ID, 'shipping_service', true );
    echo '<p>' . __( 'Shipping Service', 'woocommerce' ) . '<br>
    <input type="text" style="width:100%" id="shipping_service" name="shipping_service" value="' . esc_attr( $shipping_service ) . '"></p>';

    $tracking_number = get_post_meta( $post->ID, 'tracking_number', true );

    echo '<p>' . __( 'Tracking Number', 'woocommerce' ) . '<br>
    <input type="text" style="width:100%" id="tracking_number" name="tracking_number" value="' . esc_attr( $tracking_number ) . '"></p>';

    $shipping_date = get_post_meta( $post->ID, 'shipping_date', true );

    echo '<p>' . __( 'Shipping Date', 'woocommerce' ) . '<br>
    <input type="text" style="width:100%" id="shipping_date" name="shipping_date" value="' . esc_attr( $shipping_date ) . '"></p>';

    $shipping_date = get_post_meta( $post->ID, 'shipping_date', true );

    echo '<p>' . __( 'order_sorting', 'woocommerce' ) . '<br>
    <input type="text" style="width:100%" id="order_sorting" name="order_sorting" value="' . esc_attr( $shipping_date ) . '"></p>';

}

// For saving the metabox data.
add_action( 'save_post_shop_order', 'save_shop_order_meta_box_data' );
function save_shop_order_meta_box_data( $post_id ) {

    // If this is an autosave, our form has not been submitted, so we don't want to do anything.
    if ( defined( 'DOING_AUTOSAVE' ) && DOING_AUTOSAVE ) {
        return;
    }

    // Check the user's permissions.
    if ( ! current_user_can( 'edit_shop_order', $post_id ) ) {
        return;
    }

    // Make sure that 'shipping_service' is set.
    if ( isset( $_POST['shipping_service'] ) ) {

        // Update the meta field in the database.
        update_post_meta( $post_id, 'shipping_service', sanitize_textarea_field( $_POST['shipping_service'] ) );
    }

    // Make sure that 'tracking_number' it is set.
    if ( isset( $_POST['tracking_number'] ) ) {

        // Update the meta field in the database.
        update_post_meta( $post_id, 'tracking_number', sanitize_text_field( $_POST['tracking_number'] ) );
    }

    // Make sure that 'shipping_date' is set.
    if ( isset( $_POST['shipping_date'] ) ) {

        // Update the meta field in the database.
        update_post_meta( $post_id, 'shipping_date', sanitize_text_field( $_POST['shipping_date'] ) );
    }

    // Make sure that 'order_sorting' is set.
    if ( isset( $_POST['order_sorting'] ) ) {

        // Update the meta field in the database.
        update_post_meta( $post_id, 'order_sorting', sanitize_text_field( $_POST['order_sorting'] ) );
    }

}