WWPAY – Add Purchase Order Number field to Wholesale Payments at classic checkout

/**

   * Add Purchase Order Number field to Wholesale Payments at classic checkout.

   */

  // 1. Render the field — visible only when Wholesale Payments is selected.

  add_action( 'woocommerce_review_order_before_submit', function () {

      ?>

      <div id="wpay-po-number-field" style="display:none; margin-bottom: 1rem;">

          <p>

              <label for="wpay_purchase_order_number">

                  <?php esc_html_e( 'Purchase Order Number (optional)', 'woocommerce-wholesale-payments' ); ?>

              </label><br>

              <input

                  type="text"

                  id="wpay_purchase_order_number"

                  name="wpay_purchase_order_number"

                  class="input-text"

                  style="width: 100%;"

                  placeholder="<?php esc_attr_e( 'PO Number', 'woocommerce-wholesale-payments' ); ?>"

              />

          </p>

      </div>

      <script>

      (function ($) {

          function togglePoField() {

              if ( $('input[name="payment_method"]:checked').val() === 'wc_wholesale_payments' ) {

                  $('#wpay-po-number-field').show();

              } else {

                  $('#wpay-po-number-field').hide();

              }

          }

          $( document ).on( 'change', 'input[name="payment_method"]', togglePoField );

          $( document.body ).on( 'updated_checkout', togglePoField );

          togglePoField();

      })(jQuery);

      </script>

      <?php

  }, 20 );

  // 2. Save PO number to order meta (HPOS-compatible).

  add_action( 'woocommerce_checkout_update_order_meta', function ( $order_id ) {

      if ( ! empty( $_POST['wpay_purchase_order_number'] ) ) {

          $order = wc_get_order( $order_id );

          if ( $order ) {

              $order->update_meta_data( '_wpay_purchase_order_number', sanitize_text_field( wp_unslash(

  $_POST['wpay_purchase_order_number'] ) ) );

              $order->save();

          }

      }

  } );

  // 3. Show in order admin (below billing address).

  add_action( 'woocommerce_admin_order_data_after_billing_address', function ( $order ) {

      $po = $order->get_meta( '_wpay_purchase_order_number', true );

      if ( $po ) {

          echo '<p><strong>' . esc_html__( 'Purchase Order Number:', 'woocommerce-wholesale-payments' ) . '</strong> ' .

  esc_html( $po ) . '</p>';

      }

  } );

  // 4. Include in order confirmation emails.

  add_action( 'woocommerce_email_after_order_table', function ( $order ) {

      $po = $order->get_meta( '_wpay_purchase_order_number', true );

      if ( $po && $order->get_payment_method() === 'wc_wholesale_payments' ) {

          echo '<p><strong>' . esc_html__( 'Purchase Order Number:', 'woocommerce-wholesale-payments' ) . '</strong> ' .

  esc_html( $po ) . '</p>';

      }

  }, 10, 2 );