raise forms.ValidationError not working - django

Question

I have the following models:
class Project(models.Model):
title = models.CharField(max_length="100")
pub_date = models.DateField(auto_now_add=True, editable=False)
budget = models.IntegerField()
class Milestone(models.Model):
title = models.CharField(max_length="50")
budget_percentage = models.IntegerField(max_length=2)
project = models.ForeignKey(Project)
In the creation form for a Project, i've included an inline formset for milestones.
I want to validate that when a Project is subbmitted, at least 4 milestones are created, also that the budget_percentage of all milestones sums up to 100
This is my form:
class BaseMilestoneProjectFormSet(BaseFormSet):
def clean(self):
if any(self.errors):
# Don't bother validating the forms unless each form is valid on its own
return
if len(self.forms) < REQUIRED_MILESTONES:
raise forms.ValidationError("At least %s milestones need to be created" % REQUIRED_MILESTONES)
# Set initial control variables
# Total percentage of budget to control
total_percentage = 0
# Date to control that milestones are linear, i.e. that second milestone isn't delivered before first
current_control_date = date.min
for i, form in zip(range(len(self.forms)), self.forms):
if i == 0 and form.budget_percentage > MAX_BUDGET_FIRST_MILESTONE:
raise forms.ValidationError("First milestone budget must not exceed %s percentage" % MAX_BUDGET_FIRST_MILESTONE)
elif form.budget_percentage > MAX_BUDGET_MILESTONE:
raise forms.ValidationError("Milestone's budget must not exceed %s percentage" % MAX_BUDGET_MILESTONE)
if form.estimated_delivery_date < current_control_date:
raise forms.ValidationError("Milestones must be linear, check your delivery dates")
# Set control variables for next iteration
current_control_date = form.estimated_delivery_date
total_percentage += form.budget_percentage
if total_percentage != 100:
raise forms.ValidationError("All milestones budget percentage should sum up to 100%")
When I submit the form with 3 empty milestones forms it doesn't do nothing about the first
forms.ValidationError(...)
I've verified with raise Exception() that in fact it enters the if, but it continues as if nothing happens.
It's an error in my code or a misunderstood concept of ValidationError?
Any help would be greatly appreciated, thanks in advance.
Edit:
I'm adding the view code that was missing
class DelayedModelFormMixin(ModelFormMixin):
def form_valid(self, form):
self.object = form.save(commit=False)
self.prepare_object_for_save(self.object)
self.object.save()
if hasattr(self.object, "save_m2m"):
self.object.save_m2m()
return super(ModelFormMixin, self).form_valid(form)
def prepare_object_for_save(self, obj):
pass
class ProjectNew(CreateView, DelayedModelFormMixin):
model = Project
success_url = '/projects/project/%(slug)s'
form_class = ProjectForm
#method_decorator(login_required)
def dispatch(self, request, *args, **kwargs):
return super(ProjectNew, self).dispatch(request, *args, **kwargs)
def prepare_object_for_save(self, obj):
obj.owner = self.request.user
# Code for stacked milestones and rewards
context = self.get_context_data()
milestone_form = context['milestone_formset']
reward_form = context['reward_formset']
if milestone_form.is_valid() and reward_form.is_valid():
self.object = form.save()
milestone_form.instance = self.object
milestone_form.save()
reward_form.instance = self.object
reward_form.save()
return HttpResponseRedirect(success_url)
def form_invalid(self, form):
return self.render_to_response(self.get_context_data(form=form))
def get_context_data(self, **kwargs):
context = super(ProjectNew, self).get_context_data(**kwargs)
if self.request.POST:
context['milestone_formset'] = MilestoneFormSet(self.request.POST)
context['reward_formset'] = RewardFormSet(self.request.POST)
else:
context['milestone_formset'] = MilestoneFormSet()
context['reward_formset'] = RewardFormSet()
return context

Answer 1

If i understand your question the problem is that you are counting how many forms are inside the formset, but you want/need to count how many BOUND forms are in the formset.
So, i think you need to change this line:
if len(self.forms) < REQUIRED_MILESTONES:
for these lines:
bounded_forms = filter(lambda form:form.isbound(), self.forms)
if len(bounded_forms) < REQUIRED_MILESTONES:
then you can raise the validation error as you are doing it.
Edit:
Maybe you are not understanding how formset validation works. May be this can help, specially this phrase:
The formset clean method is called after all the Form.clean methods have been called. The errors will be found using the non_form_errors() method on the formset.
If i understand what you mean when you say
When I submit the form with 3 empty milestones forms it doesn't do nothing about the first forms.ValidationError(...)
then, you are not seeing the raised errors. So, the place to look for them is the formset "non_form_errors" method. Put something like this in your template:
<span>{{milestone_formset.non_form_errors}}</span>
Now you should see the errors you are raising in milestone formset clean method.
Hope it helps!