image.png

image.png

用python的Flask寫的服務(wù)器，web用jquery的ajax請求時(shí)候報(bào)這個(gè)錯(cuò)。
官方文檔給的說明在這里http://flask.pocoo.org/snippets/56/

簡單點(diǎn)說就是在啟動(dòng)app的地方加上一個(gè)裝飾器@crossdomain(origin='*')

from flask import Flask
app = Flask(__name__)

@app.route("/")
@crossdomain(origin='*')
def hello():
    return "Hello World!"

if __name__ == "__main__":
    app.run()

具體的裝飾器實(shí)現(xiàn)代碼也要復(fù)制進(jìn)去

from datetime import timedelta
from flask import make_response, request, current_app
from functools import update_wrapper


def crossdomain(origin=None, methods=None, headers=None,
                max_age=21600, attach_to_all=True,
                automatic_options=True):
    if methods is not None:
        methods = ', '.join(sorted(x.upper() for x in methods))
    if headers is not None and not isinstance(headers, basestring):
        headers = ', '.join(x.upper() for x in headers)
    if not isinstance(origin, basestring):
        origin = ', '.join(origin)
    if isinstance(max_age, timedelta):
        max_age = max_age.total_seconds()

    def get_methods():
        if methods is not None:
            return methods

        options_resp = current_app.make_default_options_response()
        return options_resp.headers['allow']

    def decorator(f):
        def wrapped_function(*args, **kwargs):
            if automatic_options and request.method == 'OPTIONS':
                resp = current_app.make_default_options_response()
            else:
                resp = make_response(f(*args, **kwargs))
            if not attach_to_all and request.method != 'OPTIONS':
                return resp

            h = resp.headers

            h['Access-Control-Allow-Origin'] = origin
            h['Access-Control-Allow-Methods'] = 'GET,POST,PUT,DELETE'
            h['Access-Control-Max-Age'] = str(max_age)
            if headers is not None:
                h['Access-Control-Allow-Headers'] = headers
            return resp

        f.provide_automatic_options = False
        return update_wrapper(wrapped_function, f)
    return decorator

完整代碼如下

from datetime import timedelta
from flask import make_response, request, current_app
from functools import update_wrapper


def crossdomain(origin=None, methods=None, headers=None,
                max_age=21600, attach_to_all=True,
                automatic_options=True):
    if methods is not None:
        methods = ', '.join(sorted(x.upper() for x in methods))
    if headers is not None and not isinstance(headers, basestring):
        headers = ', '.join(x.upper() for x in headers)
    if not isinstance(origin, basestring):
        origin = ', '.join(origin)
    if isinstance(max_age, timedelta):
        max_age = max_age.total_seconds()

    def get_methods():
        if methods is not None:
            return methods

        options_resp = current_app.make_default_options_response()
        return options_resp.headers['allow']

    def decorator(f):
        def wrapped_function(*args, **kwargs):
            if automatic_options and request.method == 'OPTIONS':
                resp = current_app.make_default_options_response()
            else:
                resp = make_response(f(*args, **kwargs))
            if not attach_to_all and request.method != 'OPTIONS':
                return resp

            h = resp.headers

            h['Access-Control-Allow-Origin'] = origin
            h['Access-Control-Allow-Methods'] = get_methods()
            h['Access-Control-Max-Age'] = str(max_age)
            if headers is not None:
                h['Access-Control-Allow-Headers'] = headers
            return resp

        f.provide_automatic_options = False
        return update_wrapper(wrapped_function, f)
    return decorator



from flask import Flask
app = Flask(__name__)

@app.route("/")
@crossdomain(origin='*')
def hello():
    return "Hello World!"

if __name__ == "__main__":
    app.run()

上述方法雖然可行，但是不夠完善，經(jīng)昊宇大神點(diǎn)播，采用以下辦法更合適

# -*- coding:utf-8 -*-
from flask import Flask, request
import json


def after_request(response):
    response.headers['Access-Control-Allow-Origin'] = '*'
    response.headers['Access-Control-Allow-Methods'] = 'PUT,GET,POST,DELETE'
    response.headers['Access-Control-Allow-Headers'] = 'Content-Type,Authorization'
    return response


def create_app():
    app = Flask(__name__)
    app.after_request(after_request)