Order Confirmation Email: Detecting if a BookThatApp Product is purchased

This article describes the scenario where you would like to add text to the order confirmation email sent by Shopify when an order is created that has a BookThatApp product in it.

The following liquid code can be used to see if there is a BTA product in the order:

{% assign bta = 'false' %}
{% for line in subtotal_line_items %}
  {% if line.product.metafields.bookthatapp.config %}
    {% assign bta = 'true' %}
  {% endif %}
{% endfor %}

{% if bta == 'true' %}
  <p>this note will only be shown if a BookThatApp product is in the order</p>
{% endif %}