add extra field to ModelForm

django forms modelform
sennierer picture sennierer · Jun 10, 2015 · Viewed 15.9k times · Source

I am adding an extra field to a Django ModelForm like that:

class form(forms.ModelForm):
    extra_field = forms.CharField(label='Name of Institution')
    class Meta:
        model = db_institutionInstitution
        fields = ['conn_kind','time','inst_name2']

The form is actually working fine, but I cant prepopulate it. I use it in a modelformset_factory:

formset = modelformset_factory(db_institutionInstitution,form=form)

I manually run through a queryset and add the entry in the dictionary needed for the additional form in the formset. However, when I call:

formset1 = formset(prefix='brch',queryset=qs1)

the extra_field is not prepopulated as intended (the rest is working fine).

Can anyone help?

Answer

professorDante picture professorDante · Jun 10, 2015

If you want to set a default.

extra_field = forms.CharField(label='Name of Institution', initial="harvard")

If you want to dynamically set a value put it on form initialization:

def __init__(self, *args, **kwargs):
    super(form, self).__init__(*args, **kwargs)
    self.fields['extra_field'].initial = "harvard"

Related questions

Django: Make certain fields in a ModelForm required=False

How do I make certain fields in a ModelForm required=False? If I have: class ThatForm(ModelForm): class Meta: widgets = {"text": Textarea(required=False)} Or if I have: class ThatForm(ModelForm): text = Textarea(required=False) Django returns: __init__() got an …

Read More
Django ModelForms - 'instance' not working as expected

I have a modelform that will either create a new model or edit an existing one - this is simple and should work, but for some reason I'm getting a new instance every time. The scenario is this is the …

Read More
How to allow only one radio button to be checked?

{% for each in AnswerQuery %} <form action={{address}}> <span>{{each.answer}}</span><input type='radio'> <span>Votes:{{each.answercount}}</span> <br> </form> {% endfor %} This is …

Read More