Question

In django / django / contrib / admin / templates / admin / login.html, the action path of the form is {{ app_path }}. What does it mean? Besides, in change_password_form, there is no action path at all. How can the form still work?

Answer 1

{{ app_path }} is a template variable will be replaced with the context passed to it from the view. In this case the view is in django/contrib/admin/sites.py:

@never_cache
def login(self, request, extra_context=None):
    """
    Displays the login form for the given HttpRequest.
    """
    from django.contrib.auth.views import login
    context = {
        'title': _('Log in'),
        'app_path': request.get_full_path(),
        REDIRECT_FIELD_NAME: request.get_full_path(),
    }
    context.update(extra_context or {})

    defaults = {
        'extra_context': context,
        'current_app': self.name,
        'authentication_form': self.login_form or AdminAuthenticationForm,
        'template_name': self.login_template or 'admin/login.html',
    }
    return login(request, **defaults)

so {{ app_path }} will be replaced with the value returned by request.get_full_path(), which is path where the request comes from. In this case it’s just the URL from which you loaded the form in the first place.

---

To the second question, an action of an empty string points the form at the URL the browser currently has loaded.