自定义中间件类引发错误

Question

I want to create a very simple Middleware which just prints 'OK' on every request. The problem is that it raises error:

Traceback (most recent call last):
  File "c:\python27\Lib\wsgiref\handlers.py", line 85, in run
    self.result = application(self.environ, self.start_response)
  File "C:\Users\Milano\Desktop\Projekty\venvs\sfl_venv\lib\site-packages\django\contrib\staticfiles\handlers.py", line 63, in __call__
    return self.application(environ, start_response)
  File "C:\Users\Milano\Desktop\Projekty\venvs\sfl_venv\lib\site-packages\django\core\handlers\wsgi.py", line 170, in __call__
    self.load_middleware()
  File "C:\Users\Milano\Desktop\Projekty\venvs\sfl_venv\lib\site-packages\django\core\handlers\base.py", line 52, in load_middleware
    mw_instance = mw_class()
TypeError: __init__() takes exactly 2 arguments (1 given)

The middleware class is in project/project/middleware.py

middleware.py

class UserHasProfileMiddleware(object):
    def __init__(self, get_response):
        self.get_response = get_response

    def __call__(self, request):
        response = self.get_response(request)
        print 'OK'
        return response

SETTINGS.PY

MIDDLEWARE_CLASSES = (
    'django.contrib.sessions.middleware.SessionMiddleware',
    'django.middleware.common.CommonMiddleware',
    'django.middleware.csrf.CsrfViewMiddleware',
    'django.contrib.auth.middleware.AuthenticationMiddleware',
    'django.contrib.auth.middleware.SessionAuthenticationMiddleware',
    'django.contrib.messages.middleware.MessageMiddleware',
    'django.middleware.clickjacking.XFrameOptionsMiddleware',
    'django.middleware.security.SecurityMiddleware',
    'django.middleware.locale.LocaleMiddleware',
    'SolutionsForLanguages.middleware.UserHasProfileMiddleware'
)

Do you know where is the problem?

Answer 1

Django introduced new-style middleware in Django 1.10.

Your UserHasProfileMiddleware is a new-style middleware class. Assuming you are using Django 1.10+, you should use the MIDDLEWARE setting, not MIDDLEWARE_CLASSES . All the other middlewares are from Django, so renaming the setting should be enough to fix the error.

MIDDLEWARE = (
    ...
)

If you are using Django 1.9 or earlier, you should covert your UserHasProfileMiddleware class to old-style middleware .