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pythondjangoinline-formset

Django - Find out which model instance I'm editing in an inline formset


Note: I'm new to Django and Python. I'm not sure if I've misunderstood the use of inline formsets in some way.

I needed to be able to edit certain fields for multiple instances of a Guest model (linked to a parent Invite model) at the same time in one form. After a lot of back and forth, I managed to set up an inline formset that submits successfully.

However, the interface is confusing, because you don't know which Guest you're filling in details for. Each Guest has a guest_name field, and I just want to display that name for each form, so that users know who they're editing for.

Here's my (condensed) view:

def extra_view(request, code):
    # Get the specific invite
    invite = get_invite(code)

    # Get the context from the request.
    context = RequestContext(request)

    # Store guests attending object
    guests_attending = invite.guest_set.filter(attending=True, invite=invite)

    # Create the formset for each Guest
    GuestFormset = inlineformset_factory(Invite, Guest,
                                         form=ExtraForm,
                                         fields=('diet', 'transport'),
                                         extra=0,
                                         can_delete=False)

    if request.method == "POST":
        formset = GuestFormset(request.POST, request.FILES,
                               instance=invite,
                               queryset=Guest.objects.filter(attending=1))

        if formset.is_valid():
            # Save the data to the database.
            formset.save()

            # Redirect stuff here

    if guests_attending.count() > 0:
        formset = GuestFormset(instance=invite, queryset=Guest.objects.filter(attending=1))

        # Return the view
        return render_to_response('app/extra.html', {
            'GuestForm': formset,
            'invite': invite,
            'guests_attending': guests_attending,
            'errors': formset.errors
        }, context)
    else:
        # Backup for if no guests are attending

Here's how the models look:

class Invite(models.Model):
    # Code to identify invites by
    code = models.CharField(max_length=6, default=code_generator(4, do_check=True), unique=True)
    group_name = models.CharField(max_length=200)

    def __str__(self):
        return self.group_name


class Guest(models.Model):
    invite = models.ForeignKey(Invite, on_delete=models.CASCADE)
    guest_name = models.CharField(max_length=200)
    diet = models.CharField(max_length=250, null=True, blank=True)
    transport = models.NullBooleanField(default=False)
    attending = models.NullBooleanField(default=False)

    def __str__(self):
        return self.guest_name

And here's my template

    {% if invite %}    
        <form method="post" action="">
            {% csrf_token %}
            {{ GuestForm.management_form }}
            <table>
                {% for form in GuestForm %}

                    <!-- Which guest am I editing for?! -->

                    {% for hidden in form.hidden_fields %}
                        {{ hidden }}
                    {% endfor %}

                    {% for field in form.visible_fields %}
                        {{ field.errors }}

                        <div>
                            {{ field.help_text }}
                            {{ field }}
                        </div>
                    {% endfor %}
                {% endfor %}
            </table>

            <button type="submit" class="btn">Continue</button>
        </form>
    {% endif %}

Solution

  • You can access the form's instance with form.instance. In the template, you could do something like:

    {{ form.instance.guest_name }}