Update model with a single click

Template (in our case fossils.html):

<form method="POST">
    {% csrf_token %}
    <button class="save btn" type="submit" name='fossil_favourite'>
        Favourite (on click)
    </button>
</form>

views.py: add the following code to our fossils view:

if request.method == "POST" and "fossil_favourite" in request.POST:
    if fossil.fossil_is_favourite:
        fossil.fossil_is_favourite = False
    else:
        fossil.fossil_is_favourite = True
    fossil.save()