Django Form Error: Select a valid choice. ... is not one of the available choices

Question

I am trying to create a dynamic choice field. I have a view that creates a list of tuples. The first value of the tuple is the primary key of the object ServiceWriter while the second value is the name of the ServiceWriter. The list then gets passed into the form class. When I make the selection and submit the page the form is decided to be not valid and the following form error is printed in the shell: "Select a valid choice. (First value of tuple. ie 1,2,3..) is not one of the available choices."

forms.py

class CreateAdvancedRO(forms.Form):
service_writer = forms.ChoiceField()

def __init__(self, writer_choices, *args, **kwargs):
    super(CreateAdvancedRO, self).__init__(*args, **kwargs)
    self.fields['service_writer'].choices = writer_choices
    self.helper = FormHelper()
    self.helper.form_id = 'id-create-advanced-ro'
    self.helper.form_method = 'post'
    self.helper.add_input(Submit('submit', 'Open Repair Order'))

Note: I am not using a ModelForm.

views.py
class CreateAdvancedRO(View):                                                                    
form_class = CreateAdvancedRO                                                                
writer_form = CreateServiceWriter                                                            
add_line_form = AddJobLine                                                                   

def post(self, request):                                                                     
    writer_choices = []                                                                      
    form = self.form_class(writer_choices, request.POST)                                     
    print(form.errors)                                                                       
    if form.is_valid():                                                                      
        '''Do something'''                        
    else:                                                                                                                                                                       
        writer_choices = []                                                                  
        try:                                                                                 
            writers = ServiceWriter.objects.filter(user=request.user)                        
            for writer in writers:                                                           
                writer_choices.append((str(writer.id), writer.name))                         
        except ObjectDoesNotExist:                                                           
            pass                                                                             
        form = self.form_class(writer_choices, request.POST)                                 
        writer_form = self.writer_form()                                                     
        add_line_form = self.add_line_form()                                                 
        return render(request, 'free/advanced_create.html', {'form': form, 'writer_form': wri
                                                             'add_line_form': add_line_form})

I have tried both of the following in the view:

writer_choices.append((str(writer.id), writer.name)) and
writer_choices.append((writer.id, writer.name))

Here is the ServiceWriter model, just in case.

class ServiceWriter(models.Model):
user = models.ForeignKey(User)
name = models.CharField(max_length=20, blank=False)

def __str__(self):
    return str(self.name)

Any thoughts? Thanks for the help.

Answer 1

It looks like you're trying to validate the form against an empty list of choices. Have you tried populating writer_choices before instantiating or attempting to validate the form?