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CORS errors with Flask and gevent

I have an API using Flask, Flask-SQLAlchemy and Flask-Restless, and I'm trying to make POST / PUT / DELETE requests with javascript (backbone.js, to be precise). However, I constantly encounter CORS errors - everything except GET returns an HTTP-OPTIONS 501 Not Implemented Error in the browser.

At first I tried to add the least restrictive CORS headers for all the answers:

@app.after_request def after(response): response.headers.add('Access-Control-Allow-Origin', '*') response.headers.add('Access-Control-Allow-Methods', 'POST, GET, PUT, PATCH, DELETE, OPTIONS') response.headers.add('Access-Control-Allow-Headers', 'Content-Type, X-Requested-With') response.headers.add('Access-Control-Max-Age', '1728000') return response

CORS seems to fail when the Content-Type header of the request was set to application / json (as the API requires), so a quick hack was made to get everything working:

 @app.before_request def before(): request.environ['CONTENT_TYPE'] = 'application/json'

However, everything except POST still does not work. In addition, gevent logging is enabled, but OPTIONS requests are never logged (which I think is CORS pre-sale material), even if the browser shows that they do not work with 501.

Do I need to change something in gevent or Flask in order to get CORS to work?

Edit: Running the API using the built-in flash server works, so the problem with gevent is here, but I cannot find much in the way of the documents ...

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2 answers

There is a fragment of Decorator flags for HTTP Access Control , you can use the @crossdomain (origin = '*') decorator.

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The easiest way is to use the flash cors plugin.

Install using pip

pip install -U flask-cors

Code example

 app = Flask(__name__) cors = CORS(app, resources={r"/api/*": {"origins": "*"}}) @app.route("/api/v1/users") def list_users(): return "user example"

For documentation h here is documentation of flags .

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