GraphQL入门2

将服务器端的代码升级了一下:

var GraphQLSchema = require('graphql').GraphQLSchema;

var GraphQLObjectType = require('graphql').GraphQLObjectType;

var GraphQLString = require('graphql').GraphQLString;

var GraphQLList = require('graphql').GraphQLList;

var fetch = require('node-fetch');

require("babel-polyfill");

var BASE_URL = 'http://localhost:3000';

var persons = [

{ id: "1", first_name: "Jack", last_name: "Zhang" , department: "Depart1", friends: [1] },

{ id: "2", first_name: "Tom", last_name: "Wang" , department: "Depart2", friends: [1, 2] }

];

function getPersonByUrl(args, relativeURL) {

var person = persons.find(function (item) {

if (args.id) {

return item.id == args.id;

}

if (args.department) {

return item.department == args.department;

}

});

return person;

//fetch('${BASE_URL}${relativeURL}')

//    .then(function (res) { return res.json() })

//    .then(function (json) { return json.person })

}

function getFriendByPersonId(friendID) {

var person = persons.find(function (item) {

return item.id == friendID;

});

return person;

//fetch('${BASE_URL}${relativeURL}')

//    .then(function (res) { return res.json() })

//    .then(function (json) { return json.person })

}

var PersonType = new GraphQLObjectType( {

name: 'Person',

description: '...',

fields: ()=>({

id: {

type: GraphQLString,

resolve : function (person) {

return person.first_name;

}

},

firstName: {

type: GraphQLString,

resolve : function (person) {

return person.first_name;

}

},

lastName: {

type: GraphQLString,

resolve : function (person) {

return person.last_name;

}

},

department: {

type: GraphQLString,

resolve : function (person) {

return person.department;

}

},

//email: { type: GraphQLString },

//userName: { type: GraphQLString },

//id: { type: GraphQLString },

friends: {

type: new GraphQLList(PersonType),

resolve: function (person) {

return person.friends.map(getFriendByPersonId);

}

}

})

});

var QueryType = new GraphQLObjectType({

name: 'Query',

desription: '...',

fields: {

person: {

type: PersonType,

args: {

id: { type: GraphQLString },

department: { type: GraphQLString }

},

resolve: function (obj, args, context, info) { return getPersonByUrl(args, null); }

}

}

});

var GraphQLSchemaObj = new GraphQLSchema({

query: QueryType

});

module.exports = GraphQLSchemaObj;

主要有以下几处更改:

1. 将模拟的数据源persons单独提出来成为一个全局变量.
2. 数据源中增加了department等几个属性.
3. getPersonByUrl函数支持id和department参数.
4. 增加了getFriendByPersonId函数用来解析friends属性.
5. PersonType的fields属性使用了()=>来解决friends属性中使用本类型时本类型尚未初始化的问题.

下面是客户端的测试代码:

app.js

console.log('Hello world');

////Arguments

//var Test1 = require('./Test1');

//Test1.Execute();

////Alias

//var Test2 = require('./Test2');

//Test2.Execute();

////Alias with sub-selection

//var Test3 = require('./Test3');

//Test3.Execute();

////Fragments

//var Test4 = require('./Test4');

//Test4.Execute();

//Variblies

//var Test5 = require('./Test5');

//Test5.Execute();

//Directives

//var Test6 = require('./Test6');

//Test6.Execute();

具体的测试类:

Alias:

//Test2: Aliases

var gRequest = require('graphql-request').request;

exports.Execute = function () {

const query = '{'

+ '  Depart1Person: person(department: "Depart1") {'

+ '    firstName,'

+ '    lastName,'

+ '    department'

+ '  }'

+ '  Depart2Person: person(department: "Depart2") {'

+ '    firstName,'

+ '    lastName,'

+ '    department'

+ '  }'

+ '}';

gRequest('http://localhost:1337/graphql/graphql', query).then(function (data) { console.log(data) });

};

运行结果如下:

{ Depart1Person: { firstName: 'Jack', lastName: 'Zhang', department: 'Depart1' },

Depart2Person: { firstName: 'Tom', lastName: 'Wang', department: 'Depart2' } }

Aliases -- sub selection

//Test3: Aliases -- sub selection

var gRequest = require('graphql-request').request;

var util = require('util');

exports.Execute = function () {

const query = '{'

+ '  Depart1Person: person(department: "Depart1") {'

+ '    firstName,'

+ '    lastName,'

+ '    department,'

+ '    friends'

+ '    {'

+ '     firstName,'

+ '     lastName'

+ '    }'

+ '  }'

+ '  Depart2Person: person(department: "Depart2") {'

+ '    firstName,'

+ '    lastName,'

+ '    department,'

+ '    friends'

+ '    {'

+ '     firstName,'

+ '     lastName'

+ '    }'

+ '  }'

+ '}';

gRequest('http://localhost:1337/graphql/graphql', query).then(function (data) {

console.log(util.inspect(data, { showHidden: false, depth: null }))

});

};

运行结果如下:

{ Depart1Person:

{ firstName: 'Jack',

lastName: 'Zhang',

department: 'Depart1',

friends: [ { firstName: 'Jack', lastName: 'Zhang' } ] },

Depart2Person:

{ firstName: 'Tom',

lastName: 'Wang',

department: 'Depart2',

friends:

[ { firstName: 'Jack', lastName: 'Zhang' },

{ firstName: 'Tom', lastName: 'Wang' } ] } }

Fragements:

//Test4: Fragements

var gRequest = require('graphql-request').request;

var util = require('util');

exports.Execute = function () {

var query = '{'

+ '  Depart1Person: person(department: "Depart1") {'

+ '    ...personFields'

+ '  }'

+ '  Depart2Person: person(department: "Depart2") {'

+ '    ...personFields'

+ '  }'

+ '}'

+ ''

+ 'fragment personFields on Person {'

+ '  firstName,'

+ '  lastName,'

+ '  department,'

+ '  friends{'

+ '    firstName,'

+ '    lastName'

+ '  }'

+ '}';

//gRequest('http://localhost:1337/graphql/graphql', query).then(function (data) { console.log(data) });

gRequest('http://localhost:1337/graphql/graphql', query).then(function (data) {

console.log(util.inspect(data, { showHidden: false, depth: null }))

});

};

 

运行结果如下:

{ Depart1Person:

{ firstName: 'Jack',

lastName: 'Zhang',

department: 'Depart1',

friends: [ { firstName: 'Jack', lastName: 'Zhang' } ] },

Depart2Person:

{ firstName: 'Tom',

lastName: 'Wang',

department: 'Depart2',

friends:

[ { firstName: 'Jack', lastName: 'Zhang' },

{ firstName: 'Tom', lastName: 'Wang' } ] } }

Varibles:

//Test5: Variables

var gRequest = require('graphql-request').request;

var util = require('util');

exports.Execute = function () {

var query = 'query PersonWithDept($dept: String) {'

+ ' 
person(department: $dept) {'

+ '   
...personFields'

+ ' 
}'

+ '}'

+ ''

+ 'fragment personFields on Person {'

+ ' 
firstName,'

+ ' 
lastName,'

+ '  department,'

+ ' 
friends{'

+ '   
firstName,'

+ '   
lastName'

+ ' 
}'

+ '}';

var varibles =

{

"dept": "Depart1"

};

//gRequest('http://localhost:1337/graphql/graphql',
query).then(function (data) { console.log(data) });

gRequest('http://localhost:1337/graphql/graphql', query, varibles).then(function (data) {

console.log(util.inspect(data, {
showHidden: false, depth: null }))

});

};

运行结果如下:

{ person:

{ firstName: 'Jack',

lastName: 'Zhang',

department: 'Depart1',

friends: [ { firstName:
'Jack', lastName: 'Zhang' } ] } }

Directives:

//Test6: Directives

var gRequest = require('graphql-request').request;

var util = require('util');

exports.Execute = function () {

var query = 'query PersonWithDept($dept: String, $withFriends:
Boolean!) {'

+ '  person(department: $dept) {'

+ '    ...personFields'

+ '  }'

+ '}'

+ ''

+ 'fragment personFields on
Person {'

+ '  firstName,'

+ '  lastName,'

+ '  department,'

+ '  friends @include(if: $withFriends){'

+ '    firstName,'

+ '    lastName'

+ '  }'

+ '}' ;

var varibles1 =

{

"dept": "Depart1",

"withFriends": true

};

var varibles2 =

{

"dept": "Depart1",

"withFriends": false

};

//gRequest('http://localhost:1337/graphql/graphql',
query).then(function (data) { console.log(data) });

gRequest('http://localhost:1337/graphql/graphql', query, varibles1).then(function (data) {

console.log(util.inspect(data, {
showHidden: false, depth: null }))

});

gRequest('http://localhost:1337/graphql/graphql', query, varibles2).then(function (data) {

console.log(util.inspect(data, {
showHidden: false, depth: null }))

});

};

运行结果如下:

{ person: { firstName: 'Jack', lastName: 'Zhang', department:
'Depart1' } }

{ person:

{ firstName: 'Jack',

lastName: 'Zhang',

department: 'Depart1',

friends: [ { firstName:
'Jack', lastName: 'Zhang' } ] } }

注意客户端代码中使用了,是为了打印出json的子对象,