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 name %} and {% endpartialdef %}; with the word inline it is also drawn in place, once for each item 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 the new /tasks/ page alone.

In tasks/list.html, make the <li> in the loop an inline partial named task-row, so /tasks/ still draws every row.
In tasks/views.py, add task_row(request, pk): render only that partial, passing task, or Django's 404 page.
In tasks/urls.py, add "tasks/<int:pk>/row/" named task_row.

Open /tasks/3/row/: only Call the bank (done), no heading.

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>