Snippet scAddProduct

<?php
/**
 * Adds a product to the cart
 *
 * @package simplecart
 * @author Bert Oost at OostDesign.nl
 */
$cart = $modx->getService('simplecart','SimpleCart',$modx->getOption('simplecart.core_path',null,$modx->getOption('core_path').'components/simplecart/').'model/simplecart/',$scriptProperties);
if (!($cart instanceof SimpleCart)) return '';
$cart->initialize($modx->context->get('key'));

$submitVar = $modx->getOption('submitVar', $scriptProperties, 'addcart');
$productIdVar = $modx->getOption('productIdVar', $scriptProperties, 'productid');
$quantityVar = $modx->getOption('quantityVar', $scriptProperties, 'quantity');
$redirectTo = $modx->getOption('redirectTo', $scriptProperties, false);
if(empty($redirectTo)) { $redirectTo = $modx->resource->get('id'); }
$redirectScheme = $modx->getOption('redirectScheme', $scriptProperties, 'http');

// catch the post
if(
  isset($_POST) && !empty($_POST) && isset($_POST[$submitVar]) &&
  !empty($productIdVar) && !empty($quantityVar)
) {

  $productId = (isset($_POST[$productIdVar]) && !empty($_POST[$productIdVar])) ? $_POST[$productIdVar] : $modx->resource->get('id');
  $quantity = (isset($_POST[$quantityVar]) && !empty($_POST[$quantityVar])) ? $_POST[$quantityVar] : 1;

  $options = $modx->schooks->load('cart/parseoptions', array_merge(
    $scriptProperties,
    $_REQUEST,
    array('productid' => $productId)
  ));

  // run the hook
  $added = $modx->schooks->load('cart/add', array(
    'productid' => $productId,
    'quantity' => $quantity,
    'options' => $options
  ));

  // redirect user to the cart or redirect back when not having an id set
  if($added) {

    $_SESSION['simplecart_added_product'] = $productId;
    $url = $modx->makeUrl($redirectTo, '', '', $redirectScheme);
  }
  else {

    $url = $modx->makeUrl($redirectTo, '', '&added=false', $redirectScheme);
  }

  $modx->sendRedirect($url);
}