Django 'TestForm' object has no attribute 'fields'

Question

I'm using django:

I'm trying to pass a list of tuples from views.py to a dropdown box form but I get this attribute error

forms.py

import logging                                                                   

from django import forms                                                         

log = logging.getLogger(__name__)                                                

class TestForm(forms.Form):                                                    

    def __init__(self, *args, **kwargs):                                         
        testlist = kwargs.pop('testlist',None)                               
        log.info(regionlist)                                                     
        self.fields['testlist'] = forms.ChoiceField(choices=testlist)        
        super(TestForm, self).__init__(*args, **kwargs) 

views.py

form = forms.RegionForm(regionlist=data)     

Am I using the right method to pass variables between views.py and forms.py?

Curlew

Answer 1

You need to call super first, so that the superclass sets up the fields attribute.

def __init__(self, *args, **kwargs):                                         
    testlist = kwargs.pop('testlist', None)
    log.info(regionlist)
    super(TestForm, self).__init__(*args, **kwargs)
    self.fields['testlist'] = forms.ChoiceField(choices=testlist)        

Freemasonry

This is a GREAT answer that I had to dig to find so I'm going to add some keywords to make it easier to find. To dynamically add fields to a form regardless of the form class parent (in other words, NO MODEL FORM and no need for save), this ^ allows the option to pass in named arguments to make dynamic fields. After form is instantiated (super) you can call any class functions on those variables passed in and set them to self.fields dynamically. Thus you have dynamic fields in a form that can be passed in at instantiation time. – Becht

This answer solved a form reload problem I had where the dynamic fields kept the choices from the last run. I was querying elastic search for filters that would be given back dynamically and would change, the data and the form.fields and form.base_fields were being set correctly but the cache of the form didn't seem to be When it would render it would have the old fields and wouldn't update right though I passed in the filters (new dynamic fields) to the form. Now that I pass in the dynamic fields this way and recreate the form with the request and filters it works great! Thank you Daniel. – Becht