Get the custom field value in Woocommerce Edit Order pages custom metabox

Question

enter image description here I am trying to display any value I place on the placeholder on a custom field at the admin area on the post, or an individual order page.

I have already placed get_post_meta( get_the_id(), 'total-usd', true ) inside the quotes value="" so it should not be empty, but its still shows empty when I click update.

What's seems to be wrong with my code? I appreciate your help on this.

Here is my code:

<?php

function cpmb_add_meta_box() {

    add_meta_box(
        'woocommerce-order-my-custom',
        'USD Currency display', 
        'cpmb_display_meta_box', 
        'shop_order',           
        'normal',               
        'core'
    );
}
add_action( 'add_meta_boxes', 'cpmb_add_meta_box');

function cpmb_display_meta_box( $post ) {

    wp_nonce_field( plugin_basename( __POST__ ), 'cpmb-nonce-field' );

    $html = '<label id="total-usd" for="total-usd">';
    $html .= '<strong>Total USD Currency</strong>';
    $html .= '</label><br />';
    $html .= '<input type="text" id="total-usd" name="Total USD Currency" value="' . get_post_meta( get_the_id(), 'total-usd', true ) . '" placeholder="Enter Total here" />';
    echo $html;
}

function cpmb_save_meta_box_data( $post_id ) {

    if ( cpmb_user_can_save( $post_id, 'cpmb-nonce-field' ) ){
    if ( isset( $_POST['total-usd'] ) && 0 < count( strlen( trim($_POST['total-usd'] ))))  {

            $total_usd = stripslashes( strip_tags($_POST['total-usd']));
            update_post_meta( $post_id, 'total-usd', $total_usd );
        }
    }
}
add_action( 'save_post', 'cpmb_save_meta_box_data' );

function cpmb_user_can_save( $post_id, $nonce ) {

    $is_autosave = wp_is_post_autosave( $post_id );
    $is_revision = wp_is_post_revision( $post_id );
    $is_valid_nonce = ( isset( $_POST[ $nonce ] ) && wp_verify_nonce($_POST[ $nonce ], plugin_basename( __POST__ ) ) );
    return ! ( $is_autosave || $is_revision ) && $is_valid_nonce;
}

?>

Answer 1

Your main problem is located in your <imput> text field attribute name="Total USD Currency" . It should be instead name="total-usd" . Also the html id attributes should be unique (you can't set the same ID in your and in your html tags) .

I have changed your code:

// Adding the metabox (on the right side)
add_action( 'add_meta_boxes', 'cpmb_add_meta_box');
function cpmb_add_meta_box() {

    add_meta_box(
        'woocommerce-order-my-custom',
        __('USD Currency display'),
        'cpmb_display_meta_box',
        'shop_order',
        'side',
        'core'
    );
}
// The metabox content
function cpmb_display_meta_box( $post ) {
    // Get
    $total_usd = get_post_meta( $post->ID, 'total-usd', true );

    echo '<input type="hidden" name="cpmb_total_usd_nonce" value="' . wp_create_nonce() . '">
    <label class="total-usd" for="total-usd">
    <strong>Total USD Currency</strong></label><br />
    <input type="text" id="total-usd" name="total-usd" value="' . $total_usd . '" placeholder="'. __("Enter Total here").'" />';
}

// Save/Update the meta data
add_action( 'save_post', 'cpmb_save_meta_box_data' );
function cpmb_save_meta_box_data( $post_id ) {

    // Only for shop order
    if ( 'shop_order' != $_POST[ 'post_type' ] )
        return $post_id;

    ## Security verifications. ##

    // Check if our nonce is set (and our cutom field)
    if ( ! isset( $_POST[ 'cpmb_total_usd_nonce' ] ) && isset( $_POST['total-usd'] ) )
        return $post_id;

    $nonce = $_POST[ 'cpmb_total_usd_nonce' ];

    // Verify that the nonce is valid.
    if ( ! wp_verify_nonce( $nonce ) )
        return $post_id;

    // Checking that is not an autosave
    if ( defined( 'DOING_AUTOSAVE' ) && DOING_AUTOSAVE )
        return $post_id;

    // Check the user’s permissions (for 'shop_manager' and 'administrator' user roles)
    if ( ! current_user_can( 'edit_shop_order', $post_id ) && ! current_user_can( 'edit_shop_orders', $post_id ) )
        return $post_id;


    ## SETTING AND UPDATING DATA (SECURITY PASSED) ##

    update_post_meta( $post_id, 'total-usd', sanitize_text_field( $_POST[ 'total-usd' ] ) );
}

Code goes in function.php file of your active child theme (or theme) or also in any plugin file.

This code is tested on WooCommerce versions 3+ and works.

You will get this: