Django update boolean field with a form - django

Question

My simple web-application has two models that are linked (one to many).
The first model (Newplate) has a boolean field called plate_complete. This is set to False (0) at the start.
questions:
In a html page, I am trying to build a form and button that when pressed sets the above field to True. At the moment when I click the button the page refreshes but there is no change to the database (plate_complete is still False). How do I do this?
Ideally, once the button is pressed I would also like to re-direct the user to another webpage (readplates.html). This webpage does not require the pk field (but the form does to change the specific record) Hence for now I am just refreshing the extendingplates.html file. How do I do this too ?
My code:
"""Model"""
class NewPlate(models.Model):
plate_id = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False)
title = models.CharField(max_length=200)
created_date = models.DateTimeField(default=timezone.now)
plate_complete = models.BooleanField()
"""view"""
def publish_plates(request,plate_id):
newplate = get_object_or_404(NewPlate, pk=plate_id)
newplate.plate_complete = True
newplate.save()
#2nd method
NewPlate.objects.filter(pk=plate_id).update(plate_complete = True)
return HttpResponseRedirect(reverse('tablet:extendplates', args=[plate_id]))
"""URLS"""
path('readplates', views.read_plates, name='readplates'),
path('extendplates/<pk>/', views.show_plates, name='showplates'),
path('extendplates/<pk>/', views.publish_plates, name='publishplates'),
"""HTML"""
<form method="POST" action="{% url 'tablet:publishplates' newplate.plate_id %}">
{% csrf_token %}
<button type="submit" class="button" value='True'>Publish</button></form>
-------Added show plates view:---------
def show_plates(request,pk):
mod = NewPlate.objects.all()
newplate= get_object_or_404(mod, pk=pk)
add2plate= Add2Plate.objects.filter(Add2Plateid=pk)
return render(request, 'tablet/show_plates.html', {'newplate': newplate,'add2plate': add2plate})
Thank you

Answer 1

The problem is two of your urls have the same pattern 'extendplates/<pk>/'. Django uses the first pattern that matches a url. I suppose that one of these view views.show_plates is meant to display the form and the other views.publish_plates is meant to accept the posted form data.
This means that simply both of these views should simply be a single view (to differentiate if the form is submitted we will simply check the requests method):
from django.shortcuts import redirect, render
def show_plates(request, plate_id):
newplate = get_object_or_404(NewPlate, pk=plate_id)
if request.method == "POST":
newplate.plate_complete = True
newplate.save()
return redirect('tablet:extendplates', plate_id)
context = {'newplate': newplate}
return render(request, 'your_template_name.html', context)
Now your url patterns can simply be (Note: Also captured arguments are passed as keyword arguments to the view so they should be consistent for your view and pattern):
urlpatterns = [
...
path('readplates', views.read_plates, name='readplates'),
path('extendplates/<uuid:plate_id>/', views.show_plates, name='showplates'),
...
]
In your form simply forego the action attribute as it is on the same page:
<form method="POST">
{% csrf_token %}
<button type="submit" class="button" value='True'>Publish</button>
</form>

Answer 2

You should avoid changing state on a get request like your view does currently.
Handle the POST request and change the data if the request is valid (ensuring CSRF protection).
def publish_plates(request,plate_id):
newplate = get_object_or_404(NewPlate, pk=plate_id)
if request.method == "POST":
newplate.plate_complete = True
newplate.save(update_fields=['plate_complete']) # a more efficient save
#2nd method
NewPlate.objects.filter(pk=plate_id).update(plate_complete=True)
return HttpResponseRedirect(reverse('tablet:extendplates', args=[plate_id]))
You could also put a hidden input in the form, or make a form in Django to hold the hidden input, which stores the plate_id value and that way you can have a generic URL which will fetch that ID from the POST data.
Now the real problem you've got here, is that you've got 2 URLs which are the same, but with 2 different views.
I'd suggest you change that so that URLs are unique;
path('extendplates/<pk>/', views.show_plates, name='showplates'),
path('publish-plates/<pk>/', views.publish_plates, name='publishplates'),