Deleting an Event

Part of the Forms section of Coddy's Django journey. Lesson 14 of 20.

A link is a GET, and a GET must never change data. Browsers load links ahead of time, chat apps open them to draw a preview, and search engines follow every link they find. A link that deleted an event would delete it without anyone deciding to.

So a change takes two steps: a GET shows a page that asks, and a POST, sent by a button in a form, acts. A billing app that marks an invoice as paid:

def pay_invoice(request, pk):
    invoice = get_object_or_404(Invoice, pk=pk)
    if request.method == "POST":
        invoice.paid = True
        invoice.save()
        return redirect("bills:invoice", pk=invoice.pk)
    return render(request, "bills/confirm_pay.html", {"invoice": invoice})

The confirming form needs no fields, only the token and a button; a form with no action posts to the page it is on. A row's .delete() removes it. After deleting, redirect to a page that still exists.

Challenge

Easy

The Delete this event link and its page are ready:

In delete_event, a GET only shows the page. A POST deletes the event and redirects to the list of events.
In delete_event.html, add a form that posts to this page, with a Delete button.

Press Run, open an event, and delete it.

Try it yourself

from django.shortcuts import get_object_or_404, redirect, render

from .forms import EventForm
from .models import Event


def event_list(request):
    q = request.GET.get("q", "")
    events = Event.objects.all()
    if q:
        events = events.filter(title__icontains=q)
    return render(request, "events/event_list.html", {"events": events, "q": q})


def event_detail(request, pk):
    event = get_object_or_404(Event, pk=pk)
    return render(request, "events/event_detail.html", {"event": event})


def new_event(request):
    if request.method == "POST":
        form = EventForm(request.POST)
        if form.is_valid():
            event = form.save()
            return redirect("events:detail", pk=event.pk)
    else:
        form = EventForm()
    return render(request, "events/new_event.html", {"form": form})


def edit_event(request, pk):
    event = get_object_or_404(Event, pk=pk)
    if request.method == "POST":
        form = EventForm(request.POST, instance=event)
        if form.is_valid():
            form.save()
            return redirect("events:detail", pk=event.pk)
    else:
        form = EventForm(instance=event)
    return render(request, "events/edit_event.html", {"form": form, "event": event})


def delete_event(request, pk):
    event = get_object_or_404(Event, pk=pk)
    # Delete the event only when the form is sent, then go back to the list.
    return render(request, "events/delete_event.html", {"event": event})