How to assign dropdown data to a field after importing data from view

Question

I am creating a dropdown in forms.py and to filter data I am getting a variable named layer_id . And getting in view like this layer_id = kwargs['layer_id'] . All things are good but when I assign on end to filed like this self.fields['apn'].queryset= Field.objects.filter(layer=layer) . Call goes to fields table of database rather then assigning these fields I declared in forms.py. So who can I assign to fields in forms.py

class labelModelForm(forms.ModelForm):
    model = Labels_tool_
    fields = ['apn', 'owner_name', 'situs_addr_One', 'situs_addr_Two', 'mailing_addr_One', 'mailing_addr_Two']
    apn = forms.ModelChoiceField(queryset=Field.objects.values_list('name', flat=True), empty_label="(Choose field)")

    def __init__(self, *args, **kwargs):
  //getting layer_id from views
        layer_id = kwargs['layer_id']
        print         layer_id
        layer=Layer.objects.filter(id=layer_id).first()
        x=Field.objects.filter(layer=layer)
         //On this step when modify queryset I get error
        self.fields['apn'].queryset= Field.objects.filter(layer=layer)

Answer 1

def __init__(self, *args, **kwargs):
    layer_id = kwargs.pop('layer_id', None)
    super(labelModelForm, self).__init__(*args, **kwargs)
    layer=Layer.objects.filter(id=layer_id).first()
    x=Field.objects.filter(layer=layer)
    self.fields['apn'].queryset= Field.objects.filter(layer=layer)

i hope this will help you

change your form to

class labelModelForm(forms.ModelForm):
      apn = forms.ModelChoiceField(Field.objects.values_list('name', flat=True), empty_label="(Choose field)")
    class Meta:
        model = Labels_tool_
        fields = ['apn', 'owner_name', 'situs_addr_One', 'situs_addr_Two', 'mailing_addr_One', 'mailing_addr_Two']

Answer 2

if you want to some variable to form instance, you can use get_form_kwargs method. you can use it in __init__.

#views.py

class ExampleRegisterView(CreateView):
    model = ExampleModel
    form_class = RegisterExampleForm
    template_name = 'example.html'

    def get_form_kwargs(self):
        kwargs = super().get_form_kwargs()
        kwargs['layer_id'] = 12 # for example, I give 12.
        return kwargs

#forms.py

class RegisterExampleForm(forms.ModelForm):
    apn = forms.ChoiceField(label="test")
    class Meta:
        model = ExampleModel
        fields = ['yourfield', ]
    def __init__(self, *args, **kwargs):
        layer_id = kwargs.pop('layer_id', None)
        super().__init__(*args, **kwargs)
        if layer_id:
            layer = Layer.objects.get(id=layer_id).first()
        self.fields['apn'].choices = Field.objects.filter(layer=layer)