Original source: http://djangosnippets.org/snippets/2650/ (Autor: lettoo) Description: How to automaticaly add css to all fields of a ModelForm

gistfile1.py

class MyModelForm(forms.ModelForm):
    def __init__(self, *args, **kwargs):
        super(forms.ModelForm, self).__init__(*args, **kwargs)
        for field_name in self.base_fields:
            field = self.base_fields[field_name]
            size = None
            try:
                size = field.max_length
            except:
                size = None
            if size:
                if size > 100:
                    field.widget.attrs.update({'class': 'xxlarge'})
                elif size > 50:
                    field.widget.attrs.update({'class': 'xlarge'})
                else:
                    field.widget.attrs.update({'class': 'large'})
            else:
                field.widget.attrs.update({'class': 'large'})