website/conservancy/supporters/forms.py

from django import forms

from .models import SustainerOrder

class SustainerForm(forms.ModelForm):
    amount_monthly = forms.IntegerField(initial=12, required=False)

    class Meta:
        model = SustainerOrder
        fields = [
            'name',
            'email',
            'amount',
            'acknowledge_publicly',
            'add_to_mailing_list',
            'tshirt_size',
            'street',
            'city',
            'state',
            'zip_code',
            'country',
        ]

    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        self.fields['amount'].widget.attrs['style'] = 'width: 5rem'
        self.fields['amount'].initial = 128
        self.fields['amount_monthly'].widget.attrs['style'] = 'width: 5rem'
        self.fields['tshirt_size'].widget.attrs['x-model'] = 'tshirt_size'