header - Apollo 服务器设置响应 header

Question

我目前正在使用 Apollo 服务器。我正在尝试在响应 header 中设置一个属性。并且此属性是从客户端 graphQL 请求 header 中检索的。

我在网上查了一下。并看到了诸如使用插件或扩展之类的答案。我在下面尝试过:

class FormatErrorWithContextExtension extends GraphQLExtension {
    willSendResponse(o) {
        const { context, graphqlResponse } = o;
        const { headers } = context;
        const myVar = headers['variable']
        o.graphqlResponse.http.headers.set("variable", myVar);
    }
}

function createApolloServer() {
    return new ApolloServer({
        typeDefs,
        resolvers,
        extensions: [() => new FormatErrorWithContextExtension()],
        ...
    });
}

从客户端看来，它似乎未能将其设置为响应 header 。有什么想法吗？

Answer 1

对于"apollo-server": "^2.9.11"，您可以在ApolloServer的formatResponse方法中设置自定义响应头类。

例如

server.ts:

import { ApolloServer, gql } from 'apollo-server';
import { GraphQLResponse, GraphQLRequestContext } from 'apollo-server-express/node_modules/apollo-server-core';

const typeDefs = gql`
  type Query {
    _root: String
  }
`;
const resolvers = {
  Query: {
    _root: () => '_root',
  },
};

const server = new ApolloServer({
  typeDefs,
  resolvers,
  formatResponse: (response: GraphQLResponse | null, requestContext: GraphQLRequestContext<any>) => {
    if (requestContext.response && requestContext.response.http) {
      requestContext.response.http.headers.set('custom-key', 'custom-value');
    }
    return response as GraphQLResponse;
  },
});

server.listen().then(({ url }) => {
  console.log(`Apollo server is listening on ${url}`);
});

现在，您可以从客户端获取 custom-key 响应 header 。

浏览器中的响应 header

HTTP/1.1 200 OK
X-Powered-By: Express
Access-Control-Allow-Origin: *
Content-Type: application/json; charset=utf-8
custom-key: custom-value
Content-Length: 27
ETag: W/"1b-AQpb9d3mRlH09xAPu3kjw6hdh0M"
Date: Wed, 08 Jan 2020 05:37:05 GMT
Connection: keep-alive