关于reactjs：Python Falcon和Axios：无法允许CORS

Python Falcon and Axios: Unable to allow CORS

我在允许向 Flask 服务器发出 CORS 请求时遇到了困难。客户端是使用 axios 的 React。客户端的错误是：

1	Access to XMLHttpRequest at <url> has been blocked by CORS policy: No ‘Access-Control-Allow-Origin’ header is present on the requested resource.

如果我直接在浏览器中导航到 url(在任一 PC 上)，它加载没有问题。但是当使用 axios 时它会中断。

我尝试了以下策略：

1) 直接追加头部：

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from wsgiref.simple_server import make_server
import falcon
import transform
import json
import engine

index = transform.reindex()
app = falcon.API()

class Search:
def on_get(self, request, response):
query = request.params[‘searchText’]
result = engine.search(query, index)

response.append_header(‘access-control-allow-origin’, ‘*’)
response.status = falcon.HTTP_200
response.body = json.dumps(result)

search = Search()
app.add_route(‘/search’, search)

if __name__ == ‘__main__’:
with make_server(”, 8003, app) as httpd:
print(‘Serving on port 8003…’)
httpd.serve_forever()

2) 通过中间件全局使用 falcon_cors:

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from wsgiref.simple_server import make_server
import falcon
from falcon_cors import CORS
from flask import jsonify
import transform
import json
import engine

cors = CORS(allow_origins_list=[
‘<client ip>’
])

index = transform.reindex()
app = falcon.API(middleware=[cors.middleware])

class Search:
def on_get(self, request, response):
query = request.params[‘searchText’]
result = engine.search(query, index)

response.status = falcon.HTTP_200
response.body = json.dumps(result)

search = Search()

app.add_route(‘/search’, search)

if __name__ == ‘__main__’:
with make_server(”, 8003, app) as httpd:
print(‘Serving on port 8003…’)
httpd.serve_forever()

1) 在本地使用 falcon-cors：

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from wsgiref.simple_server import make_server
import falcon

from falcon_cors import CORS

from flask import jsonify
import transform

import json
import engine

cors = CORS(allow_origins_list=[‘*’])

index = transform.reindex()
app = falcon.API(middleware=[cors.middleware])

public_cors = CORS(allow_all_origins=True)

class Search:
cors = public_cors
def on_get(self, request, response):
query = request.params[‘searchText’]

response.status = falcon.HTTP_200
response.body = json.dumps(result)

search = Search()

app.add_route(‘/search’, search)

if __name__ == ‘__main__’:
with make_server(”, 8003, app) as httpd:
print(‘Serving on port 8003…’)
httpd.serve_forever()

没有任何工作。当我在浏览器中检查响应时，我可以看到 \\’access-control-allow-origin\\’: \\’*\\’ 我在某处读到 axios 不能总是看到所有标题。有没有人遇到过这个？谢谢。

可能的情况-

当使用浏览器时，如果服务器需要它，它会在您的请求中附加 withCredentials: true。但是对于 Angular 或 React，您必须在 httpOptions.

中明确提供 withCredentials: true

我建议您使用 Falcon 或 Flask。
如果仅在 gunicorn 或 waitress 下使用 Falcon，以下过程可能会有所帮助-

获取猎鹰-cors

1	from falcon_cors import CORS

有一些列入白名单的方法。

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# Methods supported by falcon 2.0.0
# ‘CONNECT’, ‘DELETE’, ‘GET’, ‘HEAD’, ‘OPTIONS’, ‘PATCH’, ‘POST’, ‘PUT’, ‘TRACE’

whitelisted_methods = [
“GET”,
“PUT”,
“POST”,
“PATCH”,
“OPTIONS” # this is required for preflight request
]

了解有关预检请求的更多信息。

搜索类如下

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class Search:

def on_get(self, req, resp):
response_obj = {
“status”:“success”
}
resp.media = response_obj

有一些列入白名单的来源。

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whitelisted_origins = [
“http://localhost:4200”,
“https://<your-site>.com”
]

在中间件中添加 cors

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cors = CORS(
# allow_all_origins=False,
allow_origins_list=whitelisted_origins,
# allow_origins_regex=None,
# allow_credentials_all_origins=True,
# allow_credentials_origins_list=whitelisted_origins,
# allow_credentials_origins_regex=None,
allow_all_headers=True,
# allow_headers_list=[],
# allow_headers_regex=None,
# expose_headers_list=[],
# allow_all_methods=True,
allow_methods_list=whitelisted_methods
)

api = falcon.API(middleware=[
cors.middleware,
# AuthMiddleware()
# MultipartMiddleware(),
])

现在你可以为你的班级添加路线了。

1 2	from src.search import SearchResource api.add_route(‘/search’, SearchResource())

供您参考，如果传入请求中有withCredentials: true，请确保不要错过上面cors中设置为whitelisted_origins的allow_credentials_origins_list。

或

如果要允许凭据，则不应将 allow_all_origins 设置为 True。您必须在 allow_credentials_origins_list.

中指定确切的协议域端口

来源：https://www.codenong.com/59683892/

Python Falcon and Axios: Unable to allow CORS

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