Conditional checks not working while processing form in Django

Question

I have a ModelForm (EditGoalForm) which I use to edit an instance of a model (Goal). Some conditions must be met before saving form data. I used if statements to check these conditions and it still saves, instead of giving an error - like the if statement does nothing.

I have the following: models.py

class Goal(models.Model):
    goal_name = models.CharField(max_length=250)
    goal_status = models.ForeignKey(GoalStatus, on_delete=models.CASCADE, related_name='goal_status')
    user = models.ForeignKey(User, on_delete=models.CASCADE, related_name='scrumy_goal_user')

class GoalStatus(models.Model):
    status_name = models.CharField(max_length=250)

forms.py

class EditGoalForm(forms.ModelForm):
    goal_status = forms.ModelChoiceField(queryset=GoalStatus.objects.all(), empty_label="Select Goal Status")

    class Meta:
        model = Goal
        fields = ('goal_status',)

views.py

def move_goal(request, goal_id):
    goal_instance = Goal.objects.get(goal_id=goal_id)

    ERROR_MESSAGE = '''BlahBlahBlah'''

    has_perm_cannot_move_to_done = request.user.has_perm('application.cannot_move_to_done')
    has_perm_can_move_goal_anywhere = request.user.has_perm('application.can_move_goal_anywhere')
    has_perm_can_move_someones_goal_from_verify_to_done = request.user.has_perm('application.can_move_someones_goal_from_verify_to_done')
    has_perm_can_move_anybodys_goal_to_any_column = request.user.has_perm('application.can_move_anybodys_goal_to_any_column')

    if request.method == 'POST':
        form = EditGoalForm(request.POST, instance=goal_instance)
        if form.is_valid():
            if (has_perm_cannot_move_to_done and form.cleaned_data['goal_status'] != 'Done Goal'):
                form.save()
                messages.success(request, 'Goal Update Successful')
                return redirect('home')
            else:
                messages.error(request, ERROR_MESSAGE)
    else:
        form = EditGoalForm(instance=goal_instance)
    return render(request, 'move_goal.html', {'form': form})

After if form.is_valid, I checked if the authenticated user has the permission and if the goal_status field was not set to Done Goal. If both are True, then save. However, if I set the goal_status field to Done Goal, it still saves instead of displaying an error message. What could be wrong?

What kind of debugging have you attempted? Did you try to `print` some of the variables? Have you tried to use a step-by-step debugger? — DeepSpace, Aug 01 '19 at 12:12
@cagrias I have updated the question with the GoalStatus model — Caspian, Aug 01 '19 at 12:14
@DeepSpace Yes, I have printed some variables. I, however, haven't tried a step-by-step debugger — Caspian, Aug 01 '19 at 12:16
@Caspian And what was your output? If `form.cleaned_data['goal_status']` is not `'Done Goal'` there is no way that the `if` block was executed — DeepSpace, Aug 01 '19 at 12:22
@DeepSpace `print(form.cleaned_data['goal_status'] != 'Done Goal')` prints True for all instances of GoalStatus -even `Done Goal` — Caspian, Aug 01 '19 at 12:32
@Caspian Check for trailing/leading spaces/new lines. Try `form.cleaned_data['goal_status'].strip() != 'Done Goal'` — DeepSpace, Aug 01 '19 at 12:33

DeepSpace · Accepted Answer · 2019-08-01T12:49:35.107

1

form.cleaned_data['goal_status'] is an instance of GoalStatus. It can never be equal to the string 'Goal Done' unless you either:

Implement __eq__ (and/or) __ne__:

def __eq__(self, other):
    return self.status_name == other

Just compare what you really want to compare:

form.cleaned_data['goal_status'].status_name != 'Done Goal'

edited Aug 01 '19 at 12:49

answered Aug 01 '19 at 12:42

DeepSpace

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Conditional checks not working while processing form in Django

1 Answers1