CODEWITHSUNDEEP
django
Max Vallee
Max Vallee

Reputation: 468

Unique=True in Form not throwing any error

I'm entering a duplicate value (already saved in another instance of the same model) in my form to test the unique=True attribute. form.is_valid() returns 'False', as expected, but I don't receive any prompt in the template. Shouldn't I get prompted something like "obj with this value already exists"? The page simply reloads... What am I missing?

forms.py

def update_route(request, pk):

    instance = Route.objects.get(id=pk)
    
    if request.method == "POST":
        form = RouteForm(request.POST)

        if form.is_valid():
            data = form.cleaned_data
            instance.name = data['name']
            instance.priority = data['priority']
            instance.url = data['url']
            return redirect('campaigns:routes_list')

    form = RouteForm(instance=instance)

    context= {
        'form': form,
    }

    return render(request, "campaigns/route_form.html", context)

models.py

class Route(models.Model):
    name = models.CharField(max_length=48)
    priority = models.SmallIntegerField(choices=PRIORITY_LEVEL, default=0, unique=True)
    url = models.URLField()

Template

<form  method="post" action="">
    {% csrf_token %}
    {{form.as_p}}
    <input type="submit" value="Submit">
</form>

Upvotes: 0

Views: 166

Answers (1)

elyas
elyas

Reputation: 1415

Your update_route() view handles the condition in which the submitted form is valid (form.is_valid()), but not the condition in which the form is invalid.

The errors you are looking for are stored in the form object that you created with RouteForm(request.POST). The errors are generated when the is_valid() method is called.

This form object needs to be added to the context dict and rerendered to the user for the errors to surface. But your code currently overwrites that object with form = RouteForm(instance=instance), so the POST data and the related errors disappear.

One solution could be to handle it in the conditional statement:

if form.is_valid():
   ...
else:
   context = {'form': form}
   return render(request, "campaigns/route_form.html", context)

Another solution could be to create a conditional statement for GET requests, for example:

elif request.method == 'GET':
    form = RouteForm(instance=instance)

Upvotes: 2

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