grouped products for lemonstand unique product blog post

grouped_products.php

<? if ($product->grouped_products->count): ?>
  < label style="display:none;" for="product_id"><?= h($product->grouped_menu_label) ?></label>
  <select id="product_id" name="product_id" style="display:none;"  onchange="$(this).getForm().submit()">
    <? foreach ($product->grouped_products as $grouped_product): ?>
      <option <?= option_state(post('product_id'), $grouped_product->id) ?>
        value="<?= $grouped_product->id ?>">
     <?= h($grouped_product->grouped_option_desc) ?>
      </option>
    <? endforeach ?>
  </select>
<? endif ?>