Django Rest Framework: XMLHttpRequest cannot load

问题:

SOLUTION: Add a trailing slash to the end of the url...

"http://127.0.0.1:8000/xyz/api/abc/" instead of "http://127.0.0.1:8000/xyz/api/abc"

....

I have successfully created a Django Rest API and am able to store and host data locally it seems. I have built an angularjs1.0 app separately and am attempting to extract the data via $http get request however I'm running into this error:

XMLHttpRequest cannot load http://127.0.0.1:8000/xyz/api/abc. No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'http://172.20.9.163:8080' is therefore not allowed access.

I have attempted to install CORS and have added it to my INSTALLED_APPS, yet nothing seems to be working yet.

This is the get request:

getABC : function() {
            $http({
                method: 'GET',
                url: 'http://127.0.0.1:8000/xyz/api/abc',
                cache: false
            }).success(function(data) {
                console.log(data)
                callback(data);
            });
        },

Here's a look at my Django settings.py file:

INSTALLED_APPS = (
    'xyz',
    'corsheaders',
    'django.contrib.admin',
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.sessions',
    'django.contrib.messages',
    'django.contrib.staticfiles',
    'rest_framework',
)

MIDDLEWARE_CLASSES = (
    'django.contrib.sessions.middleware.SessionMiddleware',
    'corsheaders.middleware.CorsMiddleware',
    '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',

)

CORS_ORIGIN_ALLOW_ALL = True

回答1:

TL;DR

Issue your AJAX request to a slash-appended URL.

Explanation

After our discussion, it appears that the culprit is Django's automatic APPEND_SLASH = True which is enabled when CommonMiddleware is enabled.

This causes the AJAX request from your Angular app to first hit a 301 Moved Permanently redirect to the slash-appended URL. However, the corsheaders middleware does not act on this response, so the browser complains about a missing Access-Control-Allow-Origin header.

This is solved by requesting the slash-appended URL directly, and bypassing the 301 redirect altogether.

$http({
    method: 'GET',
    url: 'http://127.0.0.1:8000/xyz/api/abc/',  // trailing slash here
    cache: false
}).success(...);