WooCommerce How to Display “Product Already in Cart” Instead of “Add to Cart” Button – 2024

/*
 * Snippet: WooCommerce How to Display “Product Already in Cart” Instead of “Add to Cart” Button –  2024
 * Author: John Cook 
 * URL: https://wcsuccessacademy.com/?1088
 * Tested with WooCommerce 8.8.3
 * "check cart contents"
*/
function wcsuccess_check_cart_for_product($product_id) {
    foreach (WC()->cart->get_cart() as $cart_item_key => $cart_item) {
        if ($cart_item['product_id'] === $product_id) {
            return true;
        }
    }
    return false;
}

/*
 * Snippet: WooCommerce How to Display “Product Already in Cart” Instead of “Add to Cart” Button –  2024
 * Author: John Cook 
 * URL: https://wcsuccessacademy.com/?1088
 * Tested with WooCommerce 8.8.3
 * "Modify add to cart button with Ajax"
*/
add_action('wp_footer', function(){
?>
<script>
  document.addEventListener('DOMContentLoaded', function() {
      var addToCartButton = document.querySelector('.single_add_to_cart_button');
      var productId = addToCartButton.value;
  
      // Ensure the wcsuccess_check_cart_for_product PHP function is exposed via an AJAX endpoint and modify to your own
      fetch(`/wp-json/wcsuccess/v1/in_cart/${productId}`)
          .then(response => response.json())
          .then(isInCart => {
              if (isInCart) {
                  addToCartButton.textContent = 'Product Already in Cart';
                  addToCartButton.disabled = true;
              }
          })
          .catch(error => console.error('Error:', error));
  });
  
  // ajax add to cart compatability
  jQuery(function($) {
      // Update the button after a product is added to the cart
      $(document).on('added_to_cart', function(event, fragments, cart_hash, $button) {
          updateAddToCartButtons();
      });
  
      // Optionally, listen for a custom event if products are removed via AJAX
      $(document).on('removed_from_cart', function(event, fragments, cart_hash) {
          updateAddToCartButtons();
      });
  
      // Function to update buttons
      function updateAddToCartButtons() {
          $('.single_add_to_cart_button').each(function() {
              var button = $(this);
              var productId = button.val();
  
              fetch(`/wp-json/wcsuccess/v1/in_cart/${productId}`)
                  .then(response => response.json())
                  .then(isInCart => {
                      if (isInCart) {
                          button.text('Product Already in Cart');
                          button.prop('disabled', true);
                      } else {
                          button.text('Add to Cart'); // Change this text as necessary
                          button.prop('disabled', false);
                      }
                  })
                  .catch(error => console.error('Error:', error));
          });
      }
  
      // Initial update on page load
      updateAddToCartButtons();
  });

</script>
<?php
});

/*
 * Snippet: WooCommerce How to Display “Product Already in Cart” Instead of “Add to Cart” Button –  2024
 * Author: John Cook 
 * URL: https://wcsuccessacademy.com/?1088
 * Tested with WooCommerce 8.8.3
 * "Register api endpoint"
*/
function wcsuccess_register_rest_routes() {
    register_rest_route('wcsuccess/v1', '/in_cart/(?P<id>\d+)', array(
        'methods' => 'GET',
        'callback' => 'wcsuccess_check_cart_for_product_api',
        'permission_callback' => '__return_true',  // Adjust permission callback based on your security policy
        'args' => array(
            'id' => array(
                'validate_callback' => function($param, $request, $key) {
                    return is_numeric($param);
                }
            ),
        ),
    ));
}
add_action('rest_api_init', 'wcsuccess_register_rest_routes');

/*
 * Snippet: WooCommerce How to Display “Product Already in Cart” Instead of “Add to Cart” Button –  2024
 * Author: John Cook 
 * URL: https://wcsuccessacademy.com/?1088
 * Tested with WooCommerce 8.8.3
 * "Define callback function"
*/
function wcsuccess_check_cart_for_product_api($data) {
    $product_id = $data['id'];
    if (wcsuccess_check_cart_for_product($product_id)) {
        return new WP_REST_Response(true, 200);
    } else {
        return new WP_REST_Response(false, 200);
    }
}