How to make a RadioSelect non manditory and remove default option in a ModelForm?

Question

EDIT The reason my question is different to the possible duplicate is because that does not address the issue of making it non manditory while also removing the default option "-------"

I want to make a RadioSelect survey question non mandatory in a forms.ModelForm

To use RadioSelect I am adding the widget in my ModelForm (below) as Djangos model does not provide a RadioSelect or Select widget.

The standard way of doing this is to pass Blank=True as an argument. However as I found out in another question I asked it turns out that if you pass blank=True as an argument from models.CharField to the forms.RadioSelect widget it will leave the default option "-------" in place even if you use default=None.

I have to remove the default option "-------".

So how do I make the RadioSelect questions non mandatory while also not including the default option "-------"?

Thanks

forms.py

class SurveyFormB(forms.ModelForm): 

    class Meta:
        model = Person
        fields = ['internet_usage', 'smart_phone_ownership', 'smart_phone_usage']        

        widgets = {'internet_usage' : forms.RadioSelect,
                   'smart_phone_ownership' : forms.Select,
                   'smart_phone_usage' : forms.RadioSelect,
                   }

models.py

#How often do you use the Internet?  
INTERNET_LESS_THAN_ONE_HOUR_A_DAY = 'Less than one hour per day'
INTERNET_ONE_TO_TWO_HOURS_A_DAY = '1 - 2 hours per day'
INTERNET_TWO_TO_FOUR_HOURS_A_DAY = '2 - 4 hours per day'
INTERNET_FOUR_TO_SIX_HOURS_A_DAY = '4 - 6 hours per day'
INTERNET_SIX_TO_EIGHT_HOURS_A_DAY = '6 - 8 hours per day'
INTERNET_EIGHT_PLUS_HOURS_A_DAY = '8 + hours per day'

INTERNET_USAGE = (
    (INTERNET_LESS_THAN_ONE_HOUR_A_DAY, 'Less than one hour a day'),
    (INTERNET_ONE_TO_TWO_HOURS_A_DAY, '1 - 2 hours a day'),
    (INTERNET_TWO_TO_FOUR_HOURS_A_DAY, '2 - 4 hours a day'),
    (INTERNET_FOUR_TO_SIX_HOURS_A_DAY, '4 - 6 hours a Day'),
    (INTERNET_SIX_TO_EIGHT_HOURS_A_DAY, '6 - 8 hours a day'),
    (INTERNET_EIGHT_PLUS_HOURS_A_DAY, '8 + hours a day'),
           )

internet_usage = models.CharField(null=True, max_length=100, default=None, choices=INTERNET_USAGE, verbose_name='How long do you spend on the Internet each day?')

Food for thought, your way of creating choice `INTERNET_USAGE` is not ideal. Firstly, the tuple has same value and still has string defined twice and also `The first element in each tuple is the actual value to be set on the model, and the second element is the human-readable name.` — Nagaraj Tantri, May 13 '15 at 15:22
Thanks, I am constantly trying to improve this. Im not really a 100% sure what you mean, can you give an example of one row please? — Deepend, May 13 '15 at 16:00
Sure, think of it like this: `INTERNET_USAGE = ( ('One', 'Less than one hour a day'), ('Two', '1 - 2 hours a day'), ('Three', '2 - 4 hours a day'),......)` Now when you get the value as `One` it means the first, `Two` second option selected and so on. — Nagaraj Tantri, May 13 '15 at 16:20
So with this solution I can remove the first few lines e.g. `INTERNET_LESS_THAN_ONE_HOUR_A_DAY = 'Less than one hour per day'` ? That would massively reduce my code. — Deepend, May 13 '15 at 16:46
possible duplicate of [How to get rid of the bogus choice generated by RadioSelect of Django Form](http://stackoverflow.com/questions/5824037/how-to-get-rid-of-the-bogus-choice-generated-by-radioselect-of-django-form) — Nagaraj Tantri, May 13 '15 at 17:04
Try the answer by NickJ in http://stackoverflow.com/questions/5824037/how-to-get-rid-of-the-bogus-choice-generated-by-radioselect-of-django-form — Nagaraj Tantri, May 13 '15 at 17:04
I am looking at that answer, Its unclear where he adds the new widget he created. I have tried putting it in my models.py and forms.py but with no luck. any suggestions? — Deepend, May 13 '15 at 17:45
Could you show what have you added, that is not working? Because it can be added anywhere, but only ensure that, `widgets = {'internet_usage' : forms.RadioSelect, ...` is changed to `widgets = {'internet_usage' : RadioSelectNotNull, ...` Ensure you have the correct import statements — Nagaraj Tantri, May 14 '15 at 05:00
This worked perfectly once I changed the `forms.RadioSelect` to `RadioSelectNotNull` Thanks so much for the help and tips — Deepend, May 14 '15 at 19:00
So you want me to write an answer for this or would you be willing to close the question if you feel that its duplicate? :) — Nagaraj Tantri, May 15 '15 at 02:38
I think it is sufficiently different that It might help someone else in future. Reference NickJs solution and highlight the non mandatory nature of the Q — Deepend, May 15 '15 at 12:41

score 3 · Accepted Answer · edited May 23 '17 at 12:28

Considering the answer by NickJ and use the RadioSelectNotNull as follows:

forms.py

from itertools import chain
from django.forms import RadioSelect
from django.utils.encoding import force_unicode

class RadioSelectNotNull(RadioSelect):

    def get_renderer(self, name, value, attrs=None, choices=()):
        """Returns an instance of the renderer."""
        if value is None: value = ''
        str_value = force_unicode(value) # Normalize to string.
        final_attrs = self.build_attrs(attrs)
        choices = list(chain(self.choices, choices))
        if choices[0][0] == '':
            choices.pop(0)
        return self.renderer(name, str_value, final_attrs, choices)


class SurveyFormB(forms.ModelForm): 

    class Meta:
        model = Person
        fields = ['internet_usage', 'smart_phone_ownership', 'smart_phone_usage']        

        widgets = {'internet_usage' : RadioSelectNotNull,
                   'smart_phone_ownership' : forms.Select,
                   'smart_phone_usage' : RadioSelectNotNull,
                   }

Do note, if you can also modify the choices field as:

models.py

INTERNET_USAGE = (
    ("One", 'Less than one hour a day'),
    ( "Two", '1 - 2 hours a day'),
    ( "Three", '2 - 4 hours a day'),
    ( "Four", '4 - 6 hours a Day'),
    ( "Five", '6 - 8 hours a day'),
    ( "Six", '8 + hours a day'),
)

internet_usage = models.CharField(null=True, max_length=100, default=None, choices=INTERNET_USAGE, verbose_name='How long do you spend on the Internet each day?')

`get_renderer` is no longer a thing (using Django 3.2) – run_the_race Aug 05 '21 at 16:01 — run_the_race, Aug 05 '21 at 16:01

How to make a RadioSelect non manditory and remove default option in a ModelForm?

1 Answers1