sprockets.mixins.cors¶

This library exposes a mix-in that adds some useful CORS hooks over a basic tornado.web.RequestHandler.

Examples¶

#!/usr/bin/env python

import logging

from tornado import ioloop, web

from sprockets.mixins import cors


class SimpleRequestHandler(cors.CORSMixin, web.RequestHandler):
    """Very simple request handler that CORS enables the GET endpoint."""

    def initialize(self, creds=False, req_headers=None):
        super(SimpleRequestHandler, self).initialize()
        self.cors.allowed_methods.add('GET')
        self.cors.credentials_supported = creds
        if req_headers:
            self.cors.request_headers.update(hdr.lower() for hdr in req_headers)

    def prepare(self):
        # This is used to test that the mixin does not interfere
        # with request failures.  You really shouldn't call super()
        # after you explicitly finish() but anyway...
        if 'X-Fail' in self.request.headers:
            self.set_status(400)
            self.finish()

        super(SimpleRequestHandler, self).prepare()

    def get(self):
        self.set_status(204)
        self.finish()


if __name__ == '__main__':
    logging.basicConfig(
        level=logging.DEBUG,
        format='%(levelname)-8s %(name)s: %(message)s')
    app = web.Application([
        web.url('/public', SimpleRequestHandler),
        web.url('/private', SimpleRequestHandler, {'creds': True}),
    ], cors_origins=['http://www.example.com'], debug=True)
    app.listen(8000)

    iol = ioloop.IOLoop.instance()
    try:
        iol.start()
    except KeyboardInterrupt:
        logging.info('stopping IOLoop')
        iol.add_callback(iol.stop)

License¶

Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:

Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.

Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.

Neither the name of Sprockets nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS “AS IS” AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.