What is the meaning of redirect_field_value in django

Question

What is the meaning of this code?

{% if redirect_field_value %}
<input type="hidden" name="{{ redirect_field_name }}" value="{{ redirect_field_value }}" />
{% endif %}

Answer 1

The above html snip can be used to logout from the django app Example in SO when we are using django-allauth library, redirect_field_value is used in a form to post to the URL account_logout or account/logout and it's associated view takes care of the action

Note: by default redirect_field_name = 'next' which is passed to the function get_next_redirect_url to get the redirect url.

class LogoutView(TemplateResponseMixin, View):

    template_name = "account/logout." + app_settings.TEMPLATE_EXTENSION
    redirect_field_name = "next"

    def post(self, *args, **kwargs):
        #self.get_redirect_url method is called by passing the redirect_field_name='next' 
        #which is used further to logout the authenticated user 
        url = self.**get_redirect_url()**
        if self.request.user.is_authenticated:
            self.logout()
        response = redirect(url)
        return _ajax_response(self.request, response)

    def logout(self):
        adapter = get_adapter(self.request)
        adapter.add_message(
        self.request,
        messages.SUCCESS,
        'account/messages/logged_out.txt')
    adapter.logout(self.request)

    def get_redirect_url(self):
        return (
            get_next_redirect_url(
                self.request,
                **self.redirect_field_name**) or get_adapter(
                    self.request).get_logout_redirect_url(
                        self.request))

As I see every view(SignUp,Login,Logout) has the default rediect_field_name defined, so removing above tag will be still function when performing the logout action.

<form method="post" action="{% url 'account_logout' %}">
{% csrf_token %}
<!-- {% if redirect_field_value %}
<input type="hidden" name="{{redirect_field_name}}" value="{{redirect_field_value}}">
{% endif %} -->
<button type="submit" class="nav-link btn btn-sm sgp">SignOut</button>
</form>