Render django.forms.fields.ChoiceField object

Question

In my Django Project I have the following Problem: I would like to have a dynamic Django form. In the first step the user is asked something by the first form. When I get the postmethod the variables should be used for genereating a new form

my views.py

def calc(request):
    if request.method =="POST":
        get_form = CalculationForm(request.POST)
        if get_form.is_valid():
            op = get_form.cleaned_data['op']
            ab = get_form.cleaned_data['ab']
            alternative = AlternativForm(optype = op, wsgroup = ab)
            return render(request, 'calculated_lensar.html', {"alternativ" : alternativ})

    else:
        form = CalculationForm()
        return render(request, 'calc.html', {'form': form})

The secondform (postmethod) looks like

class AlternativForm(forms.Form):

    praep_button = ((3, 'hallo'), (4, 'tschüss'))

    def __init__(self, optype, wsgroup, *args, **kwargs):
        super(AlternativForm, self).__init__(*args, **kwargs) #dont know for what this is standing
        self.optype = optype
        self.wsgroup = wsgroup
        self.values = self.read_db()
        self.praep_button = self.buttons()
        self.felder = self.blub()
        self.neu2 = self.myfield_choices()


    def read_db(self):
        import sqlite3
        ....
        return result #tuple with 15x5 elements

    def buttons(self):
        praep_button = []
        for i in self.values:
            praep_button.append((i[4], i[1]))
        return praep_button #Just formating result from read_db in tuple(15x2)

    def blub(self):
        return forms.ChoiceField(widget=forms.RadioSelect, choices=self.praep_button)

    myfield = forms.ChoiceField(widget=forms.RadioSelect, choices=praep_button) #print --><django.forms.fields.ChoiceField object at 0x751f9b90>

    def myfield_choices(self):

        field = self['myfield'] 


    """i think here is the problem. 
    Above 'myfield' is a django.forms.fields.ChoiceField object, but here it is rendered to html (like it should be). I have the code from https://stackoverflow.com/questions/6766994/in-a-django-form-how-do-i-render-a-radio-button-so-that-the-choices-are-separat. 
    But instead i should use field = self.felder (radioselect woth tuple of the db)"""


        widget = field.field.widget

        attrs = {}
        auto_id = field.auto_id
        if auto_id and 'id' not in widget.attrs:
            attrs['id'] = auto_id
        name = field.html_name

        return widget.render(name, field.value(), attrs=attrs)
        #return widget.get_renderer(name, field.value(), attrs=attrs)

So all in all I hope the problem is clear. If i am using AlternativForm() i get the constant form. Instead i would like to get a dynamic form. If I access in views.py:

 alternative = AlternativForm(optype = op, wsgroup = ab)
 alternative = alternativ.felder

than I get . Can I render that to html?

If I set in forms.py:

 field = self.felder

than I get the error that it is a field and not a widget

Thank you for reading!

score 1 · Accepted Answer · answered Nov 23 '19 at 20:06

You just need to assign the choices in the form's __init__() method. Almost what you're doing, but instead of defining self.felder to be a field, you need to use the already initialised form's fields:

myfield = forms.ChoiceField(widget=forms.RadioSelect, choices=praep_button)

def __init__(self, optype, wsgroup, *args, **kwargs):
    super().__init__(*args, **kwargs)
    self.fields['myfield'].choices = self.get_choices(optype, wsgroup)  # create your choices in this method

def get_choices(optype, wsgroup):
    # call your other methods here
    return praep_button

Thank you very much. That was very quickly and helpful! – BG_GB_bggb Nov 24 '19 at 20:42 — BG_GB_bggb, Nov 24 '19 at 20:42

Render django.forms.fields.ChoiceField object

1 Answers1