在graphql的解析器中获取用户代理访问权限

Question

我是graphQL的相对新手，但这让我很烦。我想从客户端发送的请求正文中获取用户代理。我可以访问中间件中的用户代理，但是当我用任何参数调用下一个函数以发送到解析器时，都不会从中获取任何数据。如果我没有将任何参数传递给next（），则解析器将按预期工作，但是父级，参数，用户和会话不包含有关请求标头的任何信息。任何帮助或一般提示将不胜感激！谢谢！

app.js

import express from 'express';
import bodyParser from 'body-parser';
import mongoose from 'mongoose';
import { graphiqlExpress, graphqlExpress } from 'apollo-server-express';
import { makeExecutableSchema } from 'graphql-tools';

import typeDefs from './Graphql/typeDefs';
import resolvers from './Graphql/resolver';

import { User } from './Mongoose/Schemas/user';
import { Session } from './Mongoose/Schemas/session';

mongoose.connect('mongodb://localhost/test');

const schema = makeExecutableSchema({
  typeDefs,
  resolvers,
});

const helperMiddleware = [
  bodyParser.json(),
  bodyParser.text({ type: 'application/graphql' }),
  (req, res, next) => {
    if ( req.body ) {
      console.log(req.headers['user-agent']);
    }
    next();
  },
];

const PORT = 3009;

const app = express();

app.use('/graphql', ...helperMiddleware, graphqlExpress({ schema, context: { User, Session } }));

app.use('/graphiql', graphiqlExpress({ endpointURL: '/graphql' }));

app.listen(PORT);

console.log(`Running On Port ${PORT}`);

resolver.js

  Mutation: {
    createUser: async (parent, args, { User, Session }) => {

      const user = await new User(args).save();
      user._id = user._id.toString();

      const session = await new Session({
        user_id: user._id,
        userAgent: 'Nothing ATM',
        ip: 'Nothing ATM',
      }).save();

      return user;
    },

Answer 1

您需要使用创建GraphQL服务器中间件的回调版本，否则您将无法基于当前请求构造上下文：

https://www.apollographql.com/docs/apollo-server/setup.html#options-function