flask-cors没有解析来自ajax客户端的数据

Question

我正在使用flask为区块链项目创建一些端点。我需要接受来自ajax客户端的json数据。因为是cros平台，所以我用的是flask cors。但我似乎找不到解决办法。它不起作用

我已经试过了

from flask import Flask
from flask_cors import CORS
app = Flask(__name__)
CORS(app, origin = '*')

基本上，我的客户端代码如下所示。

$.ajax({
        url: 'http://localhost:8080/ratings/new',
        dataType: 'json',
        type: 'POST',
        contentType: 'application/json',
        data: json1,
        crossDomain: true,
        xhrFields: {
            withCredentials: true
        },
        processData: false,
        beforeSend: function (xhr) {
            //xhr.setRequestHeader('Content-Type', 'application/json; charset=utf-8');
            xhr.setRequestHeader('Access-Control-Allow-Origin', '*');
        },
        success: function (data, textStatus, jQxhr)
        {
            $('body').append(data);
            console.log(data);
        },
        error: function (jqXhr, textStatus, errorThrown) {
            console.log(errorThrown);
        }
    });

在我的服务器上，我有一个端点

@app.route('/ratings/new', methods = ['POST','OPTIONS'])
def rating():
    values = request.get_json()
    if values == None:
        return "No data received", 400
    #ratings = values['rating']
    index = blockchain.new_ratings(values)

    response = {
        'Message': f'New transaction will be added to the block {index}',
        }
    response = jsonify(response)
    response.headers.add('Access-Control-Allow-Origin','*')
    return response, 201

在服务器端，我没有接收到所需的数据，而在客户端，我得到了以下错误。

Access to XMLHttpRequest at 'http://localhost:8080/ratings/new' from origin 'null' has been blocked by CORS policy: Response to preflight request doesn't pass access control check: The value of the 'Access-Control-Allow-Credentials' header in the response is '' which must be 'true' when the request's credentials mode is 'include'. The credentials mode of requests initiated by the XMLHttpRequest is controlled by the withCredentials attribute.

请帮我解决这个问题。提前谢谢。

Answer 1

愚蠢的错误，使withCredentials: false

$.ajax({
        url: 'http://localhost:8080/ratings/new',
        dataType: 'json',
        type: 'POST',
        contentType: 'application/json',
        data: json1,
        crossDomain: true,
        xhrFields: {
            withCredentials: false
        },
        processData: false,
        beforeSend: function (xhr) {
            //xhr.setRequestHeader('Content-Type', 'application/json; charset=utf-8');
            xhr.setRequestHeader('Access-Control-Allow-Origin', '*');
        },
        success: function (data, textStatus, jQxhr)
        {
            $('body').append(data);
            console.log(data);
        },
        error: function (jqXhr, textStatus, errorThrown) {
            console.log(errorThrown);
        }
    });