django FormView¶

django FormView

Django comes with a reusable class based views and FormView is one of them.
A view for displaying a form, and rendering a template response.

When and Why to use FormView?¶

it can be used when we a functionality to submit the forms
it allows us to quickly render the page with a form with less code.
we can render forms with conditionals also by overriding few methods in the FormView when we have requirement for a conditional rendering of form.

UML diagram for FormView¶

django template view

Above is the UML diagram for FormView.
It inherits the classes BaseFormView, FormMixin, TemplateResponseMixin, ProcessFormView, ContextMixin, View.
we can check the code for FormView at github.
It comes with request methods GET and POST.
GET method will render the form with context
POST method will post the data to the server and renders the form again if has any errors otherwise it will redirect it to the success_url mentiond in the FormView.
can override get_context_data to send extra context to the template.
can override get_form_class for conditional rendering of form
can override get_success_url for conditional successful redirect.
can override form_valid and form_invalid whenever required.

Usage of FormView in django¶

Let's implement the contact us page with FormView.

contact_us.html

<html>
    <body>
        <h1> Contact Us</h1>
        <form action="" method="post">{% csrf_token %}
            {{ form.as_p }}
            <input type="submit" value="Submit" />
        </form>>
    </body>
</html>

forms.py

from django import forms

class ContactForm(forms.Form):
    name = forms.CharField()
    message = forms.CharField(widget=forms.Textarea)

    def send_email(self):
        # send email using the self.cleaned_data dictionary
        pass

views.py

from myapp.forms import ContactForm
from django.views.generic.edit import FormView

class ContactView(FormView):
    template_name = 'contact_us.html'
    form_class = ContactForm
    success_url = '/thanks/'

    def form_valid(self, form):
        # This method is called when valid form data has been POSTed.
        # It should return an HttpResponse.
        form.send_email()
        return super(ContactView, self).form_valid(form)

It's that simple to implement form submission functionality with the help of FormView otherwise it will need to write our own code which will take more development time.
By using django generic views we can rapidly reduce the development time.
Read the django github repo code to understand more about the django generic views and what to override and when.

Reference: