Remove items with checkboxes in Django forms

Question

I'm writing a form with Django. The form is a model form for a certain model, Experiment. Each Experiment has several TimeSlot models associated with it, defined with a ForeignKey('Experiment'). I'd like to have a form with the option to remove one or more TimeSlot instances from the EditExperimentForm by checking boxes.

Currently, I define all of the Checkboxes in the model by a loop in the init function in EditExperimentForm:

def __init__(self, *args, **kwargs):
    super(EditExperimentForm,self).__init__(*args,**kwargs)
    experiment = self.instance
    for timeslot in experiment.timeslot_set.all():
        self.fields['timeslot-'+str(timeslot.id)] = BooleanField(label="Remove Timeslot at "+str(timeslot.start),required=False)

And then I process them upon submission with a regular expression:

timeslot_re = re.compile(r'^timeslot-([\d]+)$')
            for key in form.data.keys():
            match = timeslot_re.match(key)
            if match:
                timeslot = TimeSlot.objects.get(id=match.expand(r'\1'))
                timeslot.delete()

This is far from an elegant solution (for one thing, it makes anything but the most generic template a straight up nightmare to work with. Can anyone think of an easier way to do this?

Answer 1

It may be a cleaner solution if you used a model formset for your TimeSlot objects. Have you looked at that at all?

http://docs.djangoproject.com/en/dev/topics/forms/modelforms/#id1

Answer 2

This code isn't tested, but something like this should do it:

class MyForm(forms.Form):
    # You can change the queryset in the __init__ method, but this should be a nice basis
    timeslots = forms.ModelMultipleChoiceFieldqueryset=Timeslot.objects.all(), widget=forms.CheckboxSelectMultiple)

    def save(self):
        # make sure you do a form.is_valid() before trying to save()
        for timeslot in self.cleaned_data['timeslots']:
            timeslot.delete()