How can I enable CORS on my Django REST Framework? the reference doesn’t help much, it says that I can do by a middleware, but how can I do that?

The link you referenced in your question recommends using django-cors-headers, whose documentation says to install the library

pip install django-cors-headers

and then add it to your installed apps:

INSTALLED_APPS = (
    ...
    'corsheaders',
    ...
)

You will also need to add a middleware class to listen in on responses:

MIDDLEWARE_CLASSES = (
    ...
    'corsheaders.middleware.CorsMiddleware',
    'django.middleware.common.CommonMiddleware',
    ...
)

Please browse the configuration section of its documentation, paying particular attention to the various CORS_ORIGIN_ settings. You’ll need to set some of those based on your needs.

pip install django-cors-headers

and then add it to your installed apps:

INSTALLED_APPS = (
    ...
    'corsheaders',
    ...
)

You will also need to add a middleware class to listen in on responses:

MIDDLEWARE_CLASSES = (
    ...
    'corsheaders.middleware.CorsMiddleware',  
    'django.middleware.common.CommonMiddleware',  
    ...
)

CORS_ORIGIN_ALLOW_ALL = True # If this is used then `CORS_ORIGIN_WHITELIST` will not have any effect
CORS_ALLOW_CREDENTIALS = True
CORS_ORIGIN_WHITELIST = [
    'http://localhost:3030',
] # If this is used, then not need to use `CORS_ORIGIN_ALLOW_ALL = True`
CORS_ORIGIN_REGEX_WHITELIST = [
    'http://localhost:3030',
]

more details: https://github.com/ottoyiu/django-cors-headers/#configuration

read the official documentation can resolve almost all problem

You can do by using a custom middleware, even though knowing that the best option is using the tested approach of the package django-cors-headers. With that said, here is the solution:

create the following structure and files:

— myapp/middleware/__init__.py

from corsMiddleware import corsMiddleware

— myapp/middleware/corsMiddleware.py

class corsMiddleware(object):
    def process_response(self, req, resp):
        resp["Access-Control-Allow-Origin"] = "*"
        return resp

add to settings.py the marked line:

MIDDLEWARE_CLASSES = (
    "django.contrib.sessions.middleware.SessionMiddleware",
    "django.middleware.common.CommonMiddleware",
    "django.middleware.csrf.CsrfViewMiddleware",

    # Now we add here our custom middleware
     'app_name.middleware.corsMiddleware' <---- this line
)

In case anyone is getting back to this question and deciding to write their own middleware, this is a code sample for Django’s new style middleware –

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

    def __call__(self, request):
        response = self.get_response(request)
        response["Access-Control-Allow-Origin"] = "*"

        return response

For Django versions > 1.10, according to the documentation, a custom MIDDLEWARE can be written as a function, let’s say in the file: yourproject/middleware.py (as a sibling of settings.py):

def open_access_middleware(get_response):
    def middleware(request):
        response = get_response(request)
        response["Access-Control-Allow-Origin"] = "*"
        response["Access-Control-Allow-Headers"] = "*"
        return response
    return middleware

and finally, add the python path of this function (w.r.t. the root of your project) to the MIDDLEWARE list in your project’s settings.py:

MIDDLEWARE = [
  .
  .
  'django.middleware.clickjacking.XFrameOptionsMiddleware',
  'yourproject.middleware.open_access_middleware'
]

Easy peasy!

Well, I don’t know guys but:

using here python 3.6 and django 2.2

Renaming MIDDLEWARE_CLASSES to MIDDLEWARE in settings.py worked.

Below are the working steps without the need for any external modules:

Step 1: Create a module in your app.

E.g, lets assume we have an app called user_registration_app. Explore user_registration_app and create a new file.

Lets call this as custom_cors_middleware.py

Paste the below Class definition:

class CustomCorsMiddleware:
    def __init__(self, get_response):
        self.get_response = get_response
        # One-time configuration and initialization.

    def __call__(self, request):
        # Code to be executed for each request before
        # the view (and later middleware) are called.

        response = self.get_response(request)
        response["Access-Control-Allow-Origin"] = "*"
        response["Access-Control-Allow-Headers"] = "*"

        # Code to be executed for each request/response after
        # the view is called.

        return response

Step 2: Register a middleware

In your projects settings.py file, add this line

‘user_registration_app.custom_cors_middleware.CustomCorsMiddleware’

E.g:

  MIDDLEWARE = [
        'user_registration_app.custom_cors_middleware.CustomCorsMiddleware', # ADD THIS LINE BEFORE CommonMiddleware
         ...
        'django.middleware.common.CommonMiddleware',

    ]

Remember to replace user_registration_app with the name of your app where you have created your custom_cors_middleware.py module.

You can now verify it will add the required response headers to all the views in the project!

Django=2.2.12 django-cors-headers=3.2.1 djangorestframework=3.11.0

Follow the official instruction doesn’t work

Finally use the old way to figure it out.

ADD:

# proj/middlewares.py
from rest_framework.authentication import SessionAuthentication


class CsrfExemptSessionAuthentication(SessionAuthentication):

    def enforce_csrf(self, request):
        return  # To not perform the csrf check previously happening

#proj/settings.py

REST_FRAMEWORK = {
    'DEFAULT_AUTHENTICATION_CLASSES': (
        'proj.middlewares.CsrfExemptSessionAuthentication',
    ),
}