Iteration (dealing with lists)

Looping over lists is a very frequent need and in this guide we'll go over the various ways you can do it.

Here are the essential aspects of iteration but you can learn more in the official documentation.

The simplest loop

Let's use the data we defined in an earlier section:

{
  "orderId": 1234,
  "orderStatus": "pending",
  "invoiceId": null,
  "client": {
    "civility": "Mr",
    "fullName": "Peter Parker",
    "isNewClient": true
  },
  "lineItems": [
    { "product": "Super strong silk",     "quantity": 100, "price": 123.45 },
    { "product": "Electronic components", "quantity": 12,  "price": 12.34 }
  ]
}

We can loop over the lineItems array to list our products using a for loop. It will repeat the code for each item in the array:

<table>
  <tr>
    <th>Product</th>
    <th>Quantity</th>
    <th>Unit Price</th>
    <th>Total</th>
  </tr>

  {% for item in lineItems %}
    <tr>
      <td>{{item.product}}</td>
      <td>{{item.quantity}}</td>
      <td>${{item.price | with_delimiter, precision: 2}}</td>
      <td>${{item.price | times: item.quantity | with_delimiter, precision: 2}}</td>
    </tr>
  {% endfor %}
</table>

The resulting HTML will look like this:

<table>
  <tr>
    <th>Product</th>
    <th>Quantity</th>
    <th>Unit Price</th>
    <th>Total</th>
  </tr>

  <tr>
    <td>Super strong silk<td>
    <td>100</td>
    <td>$123.45</td>
    <td>$12,345.00</td>
  </tr>

  <tr>
    <td>Electronic components</td>
    <td>12</td>
    <td>$12.34</td>
    <td>$148.08</td>
  </tr>
</table>

Data formatting

We're formatting the monetary values using the with_delimiter filter here. You can learn more in our documentation about built-in filters and the PDFMonkey filters.

Learn more

You can learn more about iterating over lists in the official Liquid documentation, including things like limit, offset, etc.

Related links

• The slice_by filter
• The where_exp filter

The forloop object

Inside a for loop, you get access to a special object that stores the current state of the loop. It can be useful to build special cases for the first or last iteration, for instance.

{% for item in lineItems %}
  {% if forloop.first == true %}
    <p>{{item.product}} is the first item.</p>
  {% elsif forloop.last == true %}
    <p>{{item.product}} is the last item.</p>
  {% else %}
    <p>{{item.product}} is an item.</p>
  {% endif %}
{% endfor %}

Learn more

Discover the complete range of possibilities of forloop in the dedicated documentation, including things like index, index0 or length.