Template Partials

Part of the JSON APIs section of Coddy's Django journey. Lesson 14 of 19.

A script does not always want JSON. After adding a task it may ask the server for that task's ready-made <li> and drop it into the list. A template already draws that row, so the server should reuse it.

Django 6.0 added template partials: a named piece of a template you can also render alone. Wrap it in {% partialdef %}; inline also draws it in place, on every turn of a loop. A view renders only the piece with the template's name, #, and the partial's name:

{% partialdef cart-total inline %}
    <strong>{{ cart.total }}</strong>
{% endpartialdef %}

return render(request, "shop/cart.html#cart-total", {"cart": cart})

The context must hold what the piece reads, here cart. The page and the piece share one markup, so they cannot drift apart.

Challenge

Medium

Serve one row of /tasks/ on its own:

In list.html, make the <li> a partial named task-row, still drawn for every task.
A view task_row(request, pk) that renders only that partial, and 404 for a missing task.
The route "tasks/<int:pk>/row/", named task_row.

Press Run, then open /tasks/1/row/: one row.

Try it yourself

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="utf-8">
    <title>All tasks</title>
</head>
<body>
    <h1>All tasks</h1>
    <ul id="tasks">
        {% for task in tasks %}
            <li id="task-{{ task.id }}">{{ task.title }}{% if task.done %} (done){% endif %}</li>
        {% endfor %}
    </ul>
</body>
</html>