View-wrappers Example

The settings.CAS_EXTRA_LOGIN_PARAMS allows you to define a static dictionary of extra parameters to be passed on to the CAS login page. But what if you want this dictionary to be dynamic (e.g. based on user session)?

Our current advice is to implement simple wrappers for our default views, like these ones:

from django_cas_ng import views as baseviews

@csrf_exempt
def login(request, **kwargs):
    return _add_locale(request, baseviews.LoginView.as_view()(request, **kwargs))


def logout(request, **kwargs):
    return _add_locale(request, baseviews.LoginView.as_view()(request, **kwargs))


def _add_locale(request, response):
    """If the given HttpResponse is a redirect to CAS, then add the proper
    `locale` parameter to it (and return the modified response). If not, simply
    return the original response."""

    if (
        isinstance(response, HttpResponseRedirect)
        and response['Location'].startswith(settings.CAS_SERVER_URL)
    ):
        from ourapp.some_module import get_currently_used_language
        url = response['Location']
        url += '&' if '?' in url else '&'
        url += "locale=%s" % get_currently_used_language(request)
        response['Location'] = url
    return response