Prefill MultipleChoiceField django

Question

Lets say I have the following model

class Application(models.Model):
    occupation = models.TextField()

and form

class ApplicationForm(forms.ModelForm):
    def __init__(self, *args, **kwargs)
        super().__init__(*args, **kwargs)
        self.fields['occupation'] = forms.MultipleChoiceField(choices=OCCUPATION_CHOICES, widget=CheckboxSelectMultiple)

    class Meta:
        model = Application

When I use it with a instance (for example via admin) the choices are not selected.

What am I doing wrong?

Edit: Clarification: When I select some choices, I hit submit it saves the data. They look like ['undergraduate', 'postdoc'] in the database. But they are not checked in the form anymore.

Your `super` call is wrong, it should be `super(ApplicationForm, self).__init__(*args, **kwargs)` — RodrigoDela, May 15 '16 at 09:38
No, in python3 you don't have to write it that way. https://docs.python.org/3/library/functions.html#super — Zoli, May 15 '16 at 09:41
You forgot to add `choices=OCCUPATION_CHOICES` to the `occupation` field in your `Application`model. — RodrigoDela, May 15 '16 at 09:46
If I add it there I get the following error: Select a valid choice. ['postdoc', 'professor'] is not one of the available choices. — Zoli, May 15 '16 at 09:48
it is a list of tuples: [('postdoc', 'Post-Doc'), ('professor', 'Professor / Teacher'),...] — Zoli, May 15 '16 at 09:52

score 4 · Accepted Answer · answered May 15 '16 at 11:19

I managed to get it working like this.

import ast
class ApplicationForm(forms.ModelForm):

    def __init__(self, *args, **kwargs):
        if kwargs.get('instance'):
            kwargs['initial'] = {
                'occupation': ast.literal_eval(kwargs.get('instance').occupation or '[]'),
            }
        super().__init__(*args, **kwargs)

    class Meta:
        model = Application
        widgets = {
            'occupation': CheckboxSelectMultiple(choices=OCCUPATION_CHOICES),
        }

Thanks go to RodrigoDela who made me realize what I was doing wrong and pointed me in the right direction.

score 1 · Answer 2 · edited May 23 '17 at 11:59

1

Edit: A TextField cannot store multiple choices. Take a look at this: Django Model MultipleChoice

Either you use this, or you override your forms, so that these can parse the instance.occupation content into their form.occupation field.

edited May 23 '17 at 11:59

Community

1
1

answered May 15 '16 at 09:52

RodrigoDela

1,706
12
26

Select a valid choice. ['postdoc', 'professor'] is not one of the available choices. (again) – Zoli May 15 '16 at 09:57
That error comes up in the admin? Because the code works for me. You did `makemigrations` and migrated? – RodrigoDela May 15 '16 at 10:11
Yes it is in the admin and I did the migrations. – Zoli May 15 '16 at 10:15

Prefill MultipleChoiceField django

2 Answers2