Question

我在这里使用graphql pyramida后端和最上面的graphql Yoga Express服务器。在前端，我尝试调用退出突变，但被CORS策略阻止。尽管我在我的graphql Yoga服务器中添加了cors设置，但仍然出现此错误。 GraphQL查询工作正常，但突变被阻止。我的前端URL是“ http://localhost:7777”，而Yoga Server正在运行“ http://localhost:4444/”。错误是：

Access to fetch at 'http://localhost:4444/' from origin 'http://localhost:7777' has been blocked by CORS policy: Response to preflight request doesn't pass access control check: No 'Access-Control-Allow-Origin' header is present on the requested resource. If an opaque response serves your needs, set the request's mode to 'no-cors' to fetch the resource with CORS disabled.

[Network error]: TypeError: Failed to fetch

GraphQL Yoga Server核心配置：

server.start(
{
    cors: {
        credentials: true,
        origin: [process.env.FRONTEND_URL],
    },
},
deets => {
    console.log(
        `Server is now running on port http://localhost:${deets.port}`
    );
}
);

突变：

// import React, { Component } from 'react';
import { Mutation } from 'react-apollo';
import styled from 'styled-components';
import gql from 'graphql-tag';
import { CURRENT_USER_QUERY } from './User';
import { log } from 'util';

const SIGN_OUT_MUTATION = gql`
mutation SIGN_OUT_MUTATION {
    signout {
        message
    }
}
`;

const SignOutBtn = styled.button`
color: ${props => props.theme.textMedium};
padding: 10px;
margin-right: 20px;
text-align: center;
font-family: garamond-light;
border: 1px solid ${props => props.theme.textMedium};
border-radius: 5px;
transition: background-color 0.5s ease;
transition: color 0.5s ease;
:hover {
    background: ${props => props.theme.textMedium};
    color: ${props => props.theme.white};
}
`;

const Signout = props => (
<Mutation
    mutation={SIGN_OUT_MUTATION}
    refetchQueries={[{ query: CURRENT_USER_QUERY }]}
>
    {signout => (
        <SignOutBtn
            onClick={() => {
                console.log("comes here")
                signout();
            }}
        >
            Sign Out
        </SignOutBtn>
    )}
</Mutation>
);
export default Signout;

请告诉我我在做什么错。预先感谢。

Answer 1

该问题的解决方案是编写一个设置适当的响应头的中间件，以使提取不会失败。

server.express.use(function(req, res, next) {
  res.header('Access-Control-Allow-Origin', 'http://localhost:7777');
  res.header(
    'Access-Control-Allow-Headers',
    'Origin, X-Requested-With, Content-Type, Accept'
  );
  next();
});

以上是用于解决该问题的Yoga Express服务器中间件。

Answer 2

添加这种中间件对我的情况有帮助：

server.express.use((req, res, next) => {
  res.header('Access-Control-Allow-Credentials', true)
  next()
})

Answer 3

我要做的是将字符串值数组传递给原点。以及在heroku中设置新的原点PAST_FRONTEND_URL

server.start(
  {
    cors: {
      credentials: true,
      origin: [process.env.FRONTEND_URL, process.env.PAST_FRONTEND_URL],
    },
  },
  deets => {
    console.log(`Server is now running on port http://localhost:${deets.port}`);
  }
);

Answer 4

我遇到了同样的问题，并为此解决了

server.start(
  {
    cors: {
      credentials: true,
      origin: [process.env.FRONTEND_URL],
      methods: 'GET,HEAD,PUT,PATCH,POST,DELETE',
      preflightContinue: false,
      optionsSuccessStatus: 204
    }
  },
  server => {
    console.log(`Server is running on http://localhost/${server.port}`);
  }
);

Answer 5

有时问题是与cors无关，这是后端错误。对我来说，当我将图像上传到服务器时，它会重新加载节点服务器，并且在服务器重新启动期间客户端将不会收到任何访问源标头响应，浏览器会抱怨

CORS阻止GraphQL Yoga中的突变

5 个答案: