common.py

import functools

from flask import request, Response


def require_accepts_json(f):
    """
    used as a route handler decorator to return an error
    unless the request allows responses with type "application/json"
    :param f: the function to be decorated
    :return: the decorated function
    """
    @functools.wraps(f)
    def decorated_function(*args, **kwargs):
        # TODO: use best_match to disallow */* ...?
        if not request.accept_mimetypes.accept_json:
            return Response(
                response="response will be json",
                status=406,
                mimetype="text/html")
        return f(*args, **kwargs)
    return decorated_function