Instantiate a modelForms MultiSelectCheckBox widget

Instantiate a modelForms MultiSelectCheckBox widget

I am using ModelForms with a ModelMultipleChoiceField widget. I have 2
questions:
My checkbox widget for Treatment Options from SelectOptionForStateForm
renders existing selections from the stateoption table in my database. How
does it know to look in that table for existing records? In my views.py I
am only passing the disease and state objects which do not look at the
stateoption table.
How do I instantiate my SelectOutcomeForOptionForm so that my Treatment
Outcomes checkbox is also pre-selected from the stateoptionoutcome table
in my database?
forms.py
class SelectOptionForStateForm(forms.ModelForm):
class Meta:
model = State
exclude = ['state', 'relevantdisease']
def __init__(self, *args, **kwargs):
disease=kwargs.pop('disease', None)
super(SelectOptionForStateForm, self).__init__(*args, **kwargs)
self.fields['relevantoption']=forms.ModelMultipleChoiceField(queryset=Option.objects.filter(relevantdisease_id=disease),required=True,
widget=forms.CheckboxSelectMultiple)
self.fields['relevantoption'].label="Treatment Options"
class SelectOutcomeForOptionForm(forms.ModelForm):
class Meta:
model = StateOption
exclude = ['partstate', 'partoption']
def __init__(self, *args, **kwargs):
disease=kwargs.pop('disease', None)
super(SelectOutcomeForOptionForm, self).__init__(*args, **kwargs)
self.fields['relevantoutcome']=forms.ModelMultipleChoiceField(queryset=Outcome.objects.filter(relevantdisease_id=disease),required=True,
widget=forms.CheckboxSelectMultiple)
self.fields['relevantoutcome'].label="Treatment Outcomes"
views.py
def stateoptionoutcome(request, disease_id, state_id):
state = get_object_or_404(State, pk=state_id)
disease = get_object_or_404(Disease, pk=disease_id)
if request.method == "POST":
optionForm = SelectOptionForStateForm(request.POST,
disease=disease, instance=state)
outcomeForm = SelectOutcomeForOptionForm(request.POST,
disease=disease, instance=state)
if optionForm.is_valid() and outcomeForm.is_valid():
#Deletes state objects so there are no duplicate options in the
database
try:
state_option =
StateOption.objects.filter(partstate=state).delete()
except StateOption.DoesNotExist:
state_option = None
#Saves user options to database
for option_id in request.POST.getlist('relevantoption'):
state_option = StateOption.objects.create(partstate=state,
partoption_id=int(option_id))
#Deletes stateoption objects found in StateOptionOutcome
try:
state_option_outcome =
StateOptionOutcome.objects.filter(stateoption=state_option).delete()
except StateOptionOutcome.DoesNotExist:
state_option_outcome = None
#Saves user outcomes to database
for outcome_id in request.POST.getlist('relevantoutcome'):
state_option_outcome =
StateOptionOutcome.objects.create(stateoption=state_option,
relevantoutcome_id=int(outcome_id))
return HttpResponseRedirect(reverse('diseasestateoptionlist',
kwargs={'disease_id':disease_id, 'state_id':state_id}))
models.py
class State(models.Model):
state = models.CharField(max_length=255)
relevantdisease = models.ForeignKey(Disease)
relevantoption = models.ManyToManyField(Option, through='StateOption')
class StateOption(models.Model):
partstate = models.ForeignKey(State)
partoption = models.ForeignKey(Option)
relevantoutcome = models.ManyToManyField(Outcome,
through='StateOptionOutcome')
class StateOptionOutcome(models.Model):
stateoption = models.ForeignKey(StateOption)
relevantoutcome = models.ForeignKey(Outcome)
outcomevalue = models.CharField(max_length=20)