当前端提出请求时，API标头不在Python-Tornado工作

Question

我有一个基本的CRUD应用程序，并且我正在尝试在Localhost上获得React-Redux：3000，以向后端提出请求，Python-Tornado（使用Pymongo用于数据库），在127.0.0.0.1:8888。起初，CORS阻止了所有请求，但是我在网上发现您可以添加标题以允许访问API，因此我确实喜欢：

class UserHandler(tornado.web.RequestHandler):

    def set_default_headers(self):
        self.set_header("Access-Control-Allow-Origin", "*")
        self.set_header("Access-Control-Allow-Headers", "Origin, X-Requested-With, 
        Content-Type, Accept, Authorization")
        self.set_header('Access-Control-Allow-Methods', 
        'GET,HEAD,OPTIONS,POST,PUT,DELETE')
        self.set_status(204)

    def get(self, id=None):
        {...}

    def post(self):
        {...}

    def delete(self, id):
        {...}

    def put(self, id):
        {...}

def make_app():
    return tornado.web.Application([
        (r"/users/(?P<id>\w+)", UserHandler),
        (r"/user/(?P<id>\w+)", UserHandler),
        (r"/users", UserHandler)
    ],
    debug = True,
    autoreload = True)

if __name__ == "__main__":
    app = make_app()
    port = 8888
    app.listen(port)
    print(f"
              

Answer 1

code-apprentice by code-apprentice 是正确的：请求原点与access> access-access-control-允许原素标头。

但是，为了在开发过程中（在调试模式下）保持更容易的状态，您可以始终允许当前的请求来源或设置通配符值。如果您想从多个设备进行测试（因为您不需要重新配置原始标头）也将很有用。

这就是我在项目中所做的：

class MyHandler(web.RequestHandler):
    def set_default_headers(self):
        if self.application.settings.get('debug'): # debug mode is True
            self.set_dev_cors_headers()

    def set_dev_cors_headers(self):
        # For development only
        # Not safe for production
        origin = self.request.headers.get('Origin', '*') # use current requesting origin
        self.set_header("Access-Control-Allow-Origin", origin)
        self.set_header("Access-Control-Allow-Headers", "*, content-type, authorization, x-requested-with, x-xsrftoken, x-csrftoken")
        self.set_header('Access-Control-Allow-Methods', 'POST, GET, OPTIONS, DELETE, PUT, PATCH')
        self.set_header('Access-Control-Expose-Headers', 'content-type, location, *, set-cookie')
        self.set_header('Access-Control-Request-Headers', '*')
        self.set_header('Access-Control-Allow-Credentials', 'true')

    def options(self, *args, **kwargs):
        # also set a 204 status code for OPTIONS request
        if self.application.settings.get('debug'):
            self.set_status(204)
        else:
            # perhaps do some checks in production mode
            # before setting the status code
            # ...
            self.set_status(204)
        self.finish()
    

Answer 2

您的React代码似乎向http://127.0.0.1:3000提出了请求/localhost：3000 。就标题而言，这是两个不同的主机。只要使它们俩都一样。