Define css class in django Forms

Question

Assume I have a form

class SampleClass(forms.Form):
    name = forms.CharField(max_length=30)
    age = forms.IntegerField()
    django_hacker = forms.Boolea         


        

Answer 1

Use django-widget-tweaks, it is easy to use and works pretty well.

Otherwise this can be done using a custom template filter.

Considering you render your form this way :

    {{ form.non_field_errors }}
    

        {{ form.subject.errors }}
        Email subject:
        {{ form.subject }}
    

form.subject is an instance of BoundField which has the as_widget method.

you can create a custom filter "addcss" in "my_app/templatetags/myfilters.py"

from django import template

register = template.Library()

@register.filter(name='addcss')
def addcss(value, arg):
    css_classes = value.field.widget.attrs.get('class', '').split(' ')
    if css_classes and arg not in css_classes:
        css_classes = '%s %s' % (css_classes, arg)
    return value.as_widget(attrs={'class': css_classes})

And then apply your filter:

{% load myfilters %}

    {{ form.non_field_errors }}
    

        {{ form.subject.errors }}
        Email subject:
        {{ form.subject|addcss:'MyClass' }}
    

form.subjects will then be rendered with the "MyClass" css class.

Hope this help.

EDIT 1

• Update filter according to dimyG's answer

• Add django-widget-tweak link

EDIT 2

• Update filter according to Bhyd's comment