如何正确编写GraphQL解析器?

时间:2019-01-18 09:11:32

标签: node.js graphql express-graphql

因此,据我所知,GraphQL网站上有S#* t文档,例如关于用户特殊性的嵌套查询,它使我发疯(我现在很想把我的头发拔出来)。有人可以向我解释一下左轮手枪是如何工作的,为什么我的工作不起作用吗?

问题: 我为GraphQL API创建了以下index.js文件:

var express = require('express');
var graphqlHTTP = require('express-graphql');
var { buildSchema } = require('graphql');

// Define Schemas
var schema = buildSchema(`
    type Query {
        user: User
    }
    type User {
        firstName: String
        lastName: String
        email: String
        socialMedia: SOCIALMEDIA
    }
    type SOCIALMEDIA {
        facebook: String
        instagram: String
        twitter: String
    }
`);

// Define resolver functions
var root = {
    User: {
        firstName: () => 'John',
        lastName: () => 'Doe',
        email: () => 'John.Doe@gmail.com'
    },
    SOCIALMEDIA: {
        facebook: () => 'John Doe Facebook',
        instagram: () => 'John Doe Instagram',
        twitter: () => 'John Doe Twitter'
    }

 };

var app = express();
app.use('/', graphqlHTTP({
    schema: schema,
    rootValue: root,
    graphiql: true,
}));
app.listen(8080, () => console.log('Now browse to localhost:8080'));

尽管我已尽力而为,但当我提交以下查询时:

{
  user {
    firstName
  }
}

我得到以下答案:

{
  "data": {
    "user": null
  }
}

为什么是null?!?!我什至都没有尝试过user(id: $ID): [User]迭代或任何类似于传递参数或函数的事情,甚至已经让我坚持不懈!

关于嵌套字段的工作方式我缺少什么?

编辑: 哇...好了吗?

user: () => ({
        firstName: 'John',
        lastName: 'Doe',
        email: 'John.Doe@gmail.com',
        socialMedia: {
            facebook: 'John Doe Facebook',
            instagram: 'John Doe Instagram',
            twitter: 'John Doe Twitter'
        }
    }),

这种胡说八道的硬性规定是什么?

1 个答案:

答案 0 :(得分:0)

尝试一下

// Define Schemas
var schema = buildSchema(`
    type Query {
        getUser: User
        getSocialMedia: SOCIALMEDIA
    }
    type User {
        firstName: String
        lastName: String
        email: String
        socialMedia: SOCIALMEDIA
    }
    type SOCIALMEDIA {
        facebook: String
        instagram: String
        twitter: String
    }
`);

// Define resolver functions
var root = {
    getUser: {
        firstName: () => 'John',
        lastName: () => 'Doe',
        email: () => 'John.Doe@gmail.com',
        socialMedia: {
          facebook: () => 'John Doe Facebook',
          instagram: () => 'John Doe Instagram',
          twitter: () => 'John Doe Twitter'
        }
    },
    getSocialMedia: {
        facebook: () => 'John Doe Facebook',
        instagram: () => 'John Doe Instagram',
        twitter: () => 'John Doe Twitter'
    }

 };