节点GraphQL解析来自API的空数据

Question

我正通过其官方website学习GraphQL。

我的graphql在这段代码上的用途是作为我现有的REST API的包装。 要做到这一点，我已经有这种反应的REST API：

GET: /people/:id 
RESPONSE: 
{ 
    "person": [ 
    { 
     "id": "1", 
     "userName": "mark1", 
     "firstName": "Mark", 
     "lastName": "Zuckerberg", 
     "email": "mark@facebook.com", 
     "friends": [ 
     "/people/2", 
     "/people/3" 
     ] 
    } 
    ] 
} 

，这下面的代码是我graphql模式

import { 
    GraphQLList, 
    GraphQLObjectType, 
    GraphQLString, 
    GraphQLSchema 
} from "graphql"; 

import fetch from "node-fetch"; 

const BASE_URL = "http://localhost:5000"; 

function getPersonByURL(relativeUrl) { 
    return fetch(`${BASE_URL}${relativeUrl}`) 
     .then(res => res.json()) 
     .then(json => json.person); 
} 

const PersonType = new GraphQLObjectType({ 
    name: "Person", 
    type: "Somebody", 
    fields:() => ({ 
     firstName: { 
      type: GraphQLString, 
      resolve: person => person.firstName 
     }, 
     lastName: { 
      type: GraphQLString, 
      resolve: person => person.lastName 
     }, 
     email: { 
      type: GraphQLString 
     }, 
     id: { 
      type: GraphQLString 
     }, 
     userName: { 
      type: GraphQLString 
     }, 
     friends: { 
      type: new GraphQLList(PersonType), 
      resolve: (person) => person.friends.map(getPersonByURL) 
     } 
    }) 
}); 

const QueryType = new GraphQLObjectType({ 
    name: "Query", 
    description: "the root of all queries", 
    fields:() => ({ 
     person: { 
      type: PersonType, 
      args: { 
       id: { type: GraphQLString } 
      }, 
      resolve: (root, args) => getPersonByURL(`/people/${args.id}`) 
     } 
    }) 
}); 

export default new GraphQLSchema({ 
    query: QueryType 
}); 

当我执行使用Graphiql它返回的每个字段为空的请求。 我相信我犯了错误，我代表我的JSON响应或如何从休息API访问我的JSON响应。

这些请求，并从graphiql

REQUEST 
{ 
    person(id: "1") { 
    firstName 
    } 
} 

RESPONSE 
{ 
    "data": { 
    "person": { 
     "firstName": null 
    } 
    } 
} 

结果可以请你任何提示帮助吗？

Answer 1

要找到我已经把你的JSON来要点和波纹管采用的代码修改问题：

// ... 
firstName: { 
    type: GraphQLString, 
    resolve: person => JSON.stringify(person) 
}, 
// ... 

运行以下查询后：

{ 
    person(id: "1") { 
    firstName 
    } 
} 

这里是结果：

{ 
"data": { 
    "person": { 
     "firstName": "[{\"id\":\"1\",\"userName\":\"mark1\",\"firstName\":\"Mark\",\"lastName\":\"Zuckerberg\",\"email\":\"mark@facebook.com\",\"friends\":[\"/people/2\",\"/people/3\"]}]" 
    } 
    } 
} 

您可以注意到person是数组显然它没有firstName和其他属性。你必须解开阵列或者在各个领域分解或根类型解析：

resolve: (root, args) => getPersonByURL(`/people${args.id}.json`) 
    .then(persons => persons[0]) 

这里是GraphQL Launchpad中有工作代码：https://launchpad.graphql.com/j1v0kprrp