Django Forms

Django Forms

Django forms make it easy to handle user input. The forms.Form class lets you define fields, validate data, and render HTML — all in one place.

from django import forms

class ContactForm(forms.Form):
    name = forms.CharField(max_length=100)
    email = forms.EmailField()
    message = forms.CharField(widget=forms.Textarea)
    

Each field type maps to an HTML input. Django handles validation automatically based on the field type.

Form Fields and Types

Django provides many built-in field types for different kinds of data.

from django import forms

class EventForm(forms.Form):
    title = forms.CharField(max_length=200)
    date = forms.DateField()
    capacity = forms.IntegerField(min_value=1)
    description = forms.CharField(widget=forms.Textarea, required=False)
    newsletter = forms.BooleanField(initial=True, required=False)
    

Use required=False to make fields optional. The widget argument controls how the field renders in HTML.

Validating Form Data

Call is_valid() to validate submitted data. If valid, cleaned data is available in form.cleaned_data.

def contact_view(request):
    if request.method == 'POST':
        form = ContactForm(request.POST)
        if form.is_valid():
            name = form.cleaned_data['name']
            email = form.cleaned_data['email']
            message = form.cleaned_data['message']
            return HttpResponse('Form submitted!')
    else:
        form = ContactForm()
    return render(request, 'contact.html', {'form': form})
    

Always check is_valid() before accessing cleaned data. If the form is invalid, errors are available in form.errors.

Rendering Forms in Templates

Django provides shortcut methods to render forms as HTML.

form.as_p()
form.as_table()
form.as_ul()
    

In templates, you can render the entire form or iterate over individual fields for more control.

for field in form
    field.label_tag
    field
    field.errors
    

Rendering fields individually lets you customize the layout and add CSS classes.

Handling Form Errors

When validation fails, Django populates form.errors with a dictionary of error messages.

if form.is_valid():
    pass
else:
    for field, errors in form.errors.items():
        for error in errors:
            print(f'{field}: {error}')
    

Errors are displayed alongside fields automatically when using form.as_p() or similar methods. You can also access non-field errors with form.non_field_errors().