[译+] Laravel GraphQL ReadMe 文档

原文地址:

使用

语法 / Schemas

从 1.0 版本开始, 可以定义多个语法, 如果您想要一个公共的入口，另一个需要身份验证的入口，那么拥有多个语法是非常有用的。

您可以在配置中定义多个语法:

'schema' => 'default',

'schemas' => [
    'default' => [
        'query' => [
            //'users' => 'App\GraphQL\Query\UsersQuery'
        ],
        'mutation' => [
            //'updateUserEmail' => 'App\GraphQL\Query\UpdateUserEmailMutation'
        ]
    ],
    'secret' => [
        'query' => [
            //'users' => 'App\GraphQL\Query\UsersQuery'
        ],
        'mutation' => [
            //'updateUserEmail' => 'App\GraphQL\Query\UpdateUserEmailMutation'
        ]
    ]
]

或者可以使用 facade 来添加语法

GraphQL::addSchema('secret', [
    'query' => [
        'users' => 'App\GraphQL\Query\UsersQuery'
    ],
    'mutation' => [
        'updateUserEmail' => 'App\GraphQL\Query\UpdateUserEmailMutation'
    ]
]);

随后, 你可以使用 facade 来创建语法

// Will return the default schema defined by 'schema' in the config
$schema = GraphQL::schema();

// Will return the 'secret' schema
$schema = GraphQL::schema('secret');

// Will build a new schema
$schema = GraphQL::schema([
    'query' => [
        //'users' => 'App\GraphQL\Query\UsersQuery'
    ],
    'mutation' => [
        //'updateUserEmail' => 'App\GraphQL\Query\UpdateUserEmailMutation'
    ]
]);

你可以通过指定的语法来访问

// Default schema
http://homestead.app/graphql?query=query+FetchUsers{users{id,email}}

// Secret schema
http://homestead.app/graphql/secret?query=query+FetchUsers{users{id,email}}

创建查询

首先你需要创建一个类型

namespace App\GraphQL\Type;

use GraphQL\Type\Definition\Type;
use Folklore\GraphQL\Support\Type as GraphQLType;

class UserType extends GraphQLType
{
    protected $attributes = [
        'name' => 'User',
        'description' => 'A user'
    ];

    /*
    * Uncomment following line to make the type input object.
    * http://graphql.org/learn/schema/#input-types
    */
    // protected $inputObject = true;

    public function fields()
    {
        return [
            'id' => [
                'type' => Type::nonNull(Type::string()),
                'description' => 'The id of the user'
            ],
            'email' => [
                'type' => Type::string(),
                'description' => 'The email of user'
            ]
        ];
    }

    // If you want to resolve the field yourself, you can declare a method
    // with the following format resolve[FIELD_NAME]Field()
    protected function resolveEmailField($root, $args)
    {
        return strtolower($root->email);
    }
}

然后将类型添加到 config/graphql.php 文件中

'types' => [
    'User' => 'App\GraphQL\Type\UserType'
]

你也可以使用 GraphQL Facade 来进行添加, 添加到 service provider 中

GraphQL::addType('App\GraphQL\Type\UserType', 'User');

然后, 你需要定义一个查询并且返回这个类型(或者列表). 你同样也可以在指定的参数, 这些参数可以用在 resolve 方法中.

namespace App\GraphQL\Query;

use GraphQL;
use GraphQL\Type\Definition\Type;
use Folklore\GraphQL\Support\Query;
use App\User;

class UsersQuery extends Query
{
    protected $attributes = [
        'name' => 'users'
    ];

    public function type()
    {
        return Type::listOf(GraphQL::type('User'));
    }

    public function args()
    {
        return [
            'id' => ['name' => 'id', 'type' => Type::string()],
            'email' => ['name' => 'email', 'type' => Type::string()]
        ];
    }

    public function resolve($root, $args)
    {
        if (isset($args['id'])) {
            return User::where('id' , $args['id'])->get();
        } else if(isset($args['email'])) {
            return User::where('email', $args['email'])->get();
        } else {
            return User::all();
        }
    }
}

添加 query 到 config/graphql.php 文件中

'schemas' => [
    'default' => [
        'query' => [
            'users' => 'App\GraphQL\Query\UsersQuery'
        ],
        // ...
    ]
]

这样就OK了, 你可以使用 /graphql 来进行查询了. 尝试使用 get 请求来获取下数据

query FetchUsers {
  users {
    id
    email
  }
}

或者使用 url 地址来进行请求

http://homestead.app/graphql?query=query+FetchUsers{users{id,email}}

创建修改

更改就是另外一种形式的查询, 他接受参数(用来进行更改或者创建使用的)并且返回一个对象或者指定的类型

例如使用修改来更新用户的密码, 首先你需要定义 mutation

namespace App\GraphQL\Mutation;

use GraphQL;
use GraphQL\Type\Definition\Type;
use Folklore\GraphQL\Support\Mutation;
use App\User;

class UpdateUserPasswordMutation extends Mutation
{
    protected $attributes = [
        'name' => 'updateUserPassword'
    ];

    public function type()
    {
        return GraphQL::type('User');
    }

    public function args()
    {
        return [
            'id' => ['name' => 'id', 'type' => Type::nonNull(Type::string())],
            'password' => ['name' => 'password', 'type' => Type::nonNull(Type::string())]
        ];
    }

    public function resolve($root, $args)
    {
        $user = User::find($args['id']);

        if (!$user) {
            return null;
        }

        $user->password = bcrypt($args['password']);
        $user->save();

        return $user;
    }
}

就想 resolve 方法. 你使用参数来更新你的模型并且返回她.

然后添加 mutation 到 config/graphql.php 文件中

'schema' => [
    'default' => [
        'mutation' => [
            'updateUserPassword' => 'App\GraphQL\Mutation\UpdateUserPasswordMutation'
        ],
        // ...
    ]
]

你可以使用如下的查询来进行修改

mutation users {
  updateUserPassword(id: "1", password: "newpassword") {
    id
    email
  }
}

url 中可以如下请求

http://homestead.app/graphql?query=mutation+users{updateUserPassword(id: "1", password: "newpassword"){id,email}}

添加修改验证

在修改中增加验证是可以的. 老铁. 它使用 laravel Validator 来处理验证并且返回相应的参数.

当创建 mutation 的时候, 你可以添加如下方法来定义验证规则:

namespace App\GraphQL\Mutation;

use GraphQL;
use GraphQL\Type\Definition\Type;
use Folklore\GraphQL\Support\Mutation;
use App\User;

class UpdateUserEmailMutation extends Mutation
{
    protected $attributes = [
        'name' => 'UpdateUserEmail'
    ];

    public function type()
    {
        return GraphQL::type('User');
    }

    public function args()
    {
        return [
            'id' => ['name' => 'id', 'type' => Type::string()],
            'email' => ['name' => 'email', 'type' => Type::string()]
        ];
    }

    public function rules()
    {
        return [
            'id' => ['required'],
            'email' => ['required', 'email']
        ];
    }

    public function resolve($root, $args)
    {
        $user = User::find($args['id']);

        if (!$user) {
            return null;
        }

        $user->email = $args['email'];
        $user->save();

        return $user;
    }
}

同样, 你可以在参数中定义规则:

class UpdateUserEmailMutation extends Mutation
{
    //...

    public function args()
    {
        return [
            'id' => [
                'name' => 'id',
                'type' => Type::string(),
                'rules' => ['required']
            ],
            'email' => [
                'name' => 'email',
                'type' => Type::string(),
                'rules' => ['required', 'email']
            ]
        ];
    }

    //...
}

当你执行修改的时候, 会返回验证错误. 由于 GraphQL 规范定义了错误的格式，因此会将验证错误消息作为额外的 validation 属性添加到错误对象中。为了找到验证错误，应该检查一个 message 等于 validation 的时候，然后 validation 属性将包含 Laravel Validator 返回的正常错误消息信息.

{
  "data": {
    "updateUserEmail": null
  },
  "errors": [
    {
      "message": "validation",
      "locations": [
        {
          "line": 1,
          "column": 20
        }
      ],
      "validation": {
        "email": [
          "The email is invalid."
        ]
      }
    }
  ]
}

高级用法

查询变量

GraphQL 允许你使用变量来查询数据, 从而不用在查询中硬编码值. 如下

query FetchUserByID($id: String) {
    user(id: $id) {
        id
        email
    }
}

当你查询 GraphQL 的时候可以传递 variables 参数

http://homestead.app/graphql?query=query+FetchUserByID($id:String){user(id:$id){id,email}}&variables={"id":"1"}

查询嵌入资源

如果想查询嵌入资源

query FetchUser{
    user(id: 123456789) {
        id
        posts(id: 987654321) {
            id
        }
    }
}

你需要在 UserType 中添加 post 字段并且实现 resolveField 方法

public function fields()
{
    return [
        'id' => [
            'type'        => Type::nonNull(Type::string()),
            'description' => 'Id of user',
        ],
        'posts' => [
            'args' => [
                'id' => [
                    'type'        => Type::string(),
                    'description' => 'id of the post',
                ],
            ],
            'type'        => Type::listOf(GraphQL::type('Post')),
            'description' => 'post description',
        ],
    ];
}
    
public function resolvePostsField($root, $args)
{
    if (isset($args['id'])) {
        return  $root->posts->where('id', $args['id']);
    }

    return $root->posts;
}

枚举

美剧类型是一个特殊类型的标量变量, 用来限制一系列的允许的数据, 可以查看这里阅读更多的信息

首先创建一个 Enum 作为 GraphQLType 的扩展类型

<?php
// app/GraphQL/Enums/EpisodeEnum.php
namespace App\GraphQL\Enums;

use Folklore\GraphQL\Support\Type as GraphQLType;

class EpisodeEnum extends GraphQLType {
    protected $enumObject = true;

    protected $attributes = [
        'name' => 'Episode',
        'description' => 'The types of demographic elements',
        'values' => [
            'NEWHOPE' => 'NEWHOPE',
            'EMPIRE' => 'EMPIRE',
            'JEDI' => 'JEDI',
        ],
    ];
}

// config/graphql.php
'types' => [TestEnum' => TestEnumType::class ];

然后如下使用

<?php
// app/GraphQL/Type/TestType.php
class TestType extends GraphQLType {
   public function fields()
   {
        return [
            'type' => [
                'type' => GraphQL::type('TestEnum')
            ]
        ]
   }
}

接口

你可以使用接口来限制一系列的字段, 阅读更多的消息点击这里

一系列的接口

<?php
// app/GraphQL/Interfaces/CharacterInterface.php
namespace App\GraphQL\Interfaces;

use GraphQL;
use Folklore\GraphQL\Support\InterfaceType;
use GraphQL\Type\Definition\Type;

class CharacterInterface extends InterfaceType {
    protected $attributes = [
            'name' => 'Character',
            'description' => 'Character interface.',
        ];
    
        public function fields() {
            return [
                'id' => [
                    'type' => Type::nonNull(Type::int()),
                    'description' => 'The id of the character.'
                ],
                'appearsIn' => [
                    'type' => Type::nonNull(Type::listOf(GraphQL::type('Episode'))),
                    'description' => 'A list of episodes in which the character has an appearance.'
                ],
            ];
        }
    
        public function resolveType($root) {
            // Use the resolveType to resolve the Type which is implemented trough this interface
            $type = $root['type'];
            if ($type === 'human') {
                return GraphQL::type('Human');
            } else if  ($type === 'droid') {
                return GraphQL::type('Droid');
            }
        }
}

类型实现

<?php
// app/GraphQL/Types/HumanType.php
namespace App\GraphQL\Types;

use GraphQL;
use Folklore\GraphQL\Support\Type as GraphQLType;
use GraphQL\Type\Definition\Type;

class HumanType extends GraphQLType {

    protected $attributes = [
        'name' => 'Human',
        'description' => 'A human.'
    ];

    public function fields() {
        return [
            'id' => [
                'type' => Type::nonNull(Type::int()),
                'description' => 'The id of the human.',
            ],
            'appearsIn' => [
                'type' => Type::nonNull(Type::listOf(GraphQL::type('Episode'))),
                'description' => 'A list of episodes in which the human has an appearance.'
            ],
            'totalCredits' => [
                'type' => Type::nonNull(Type::int()),
                'description' => 'The total amount of credits this human owns.'
            ]
        ];
    }

    public function interfaces() {
        return [
            GraphQL::type('Character')
        ];
    }
}

自定义字段

你同样可以定义一个字段类, 如果你想在多个类型中重用他们.

namespace App\GraphQL\Fields;

use GraphQL\Type\Definition\Type;
use Folklore\GraphQL\Support\Field;

class PictureField extends Field {

        protected $attributes = [
        'description' => 'A picture'
    ];

    public function type(){
        return Type::string();
    }

    public function args()
    {
        return [
            'width' => [
                'type' => Type::int(),
                'description' => 'The width of the picture'
            ],
            'height' => [
                'type' => Type::int(),
                'description' => 'The height of the picture'
            ]
        ];
    }

    protected function resolve($root, $args)
    {
        $width = isset($args['width']) ? $args['width']:100;
        $height = isset($args['height']) ? $args['height']:100;
        return 'http://placehold.it/'.$width.'x'.$height;
    }

}

你可以在 type 声明中使用他们

namespace App\GraphQL\Type;

use GraphQL\Type\Definition\Type;
use Folklore\GraphQL\Support\Type as GraphQLType;

use App\GraphQL\Fields\PictureField;

class UserType extends GraphQLType {

        protected $attributes = [
        'name' => 'User',
        'description' => 'A user'
    ];

    public function fields()
    {
        return [
            'id' => [
                'type' => Type::nonNull(Type::string()),
                'description' => 'The id of the user'
            ],
            'email' => [
                'type' => Type::string(),
                'description' => 'The email of user'
            ],
            //Instead of passing an array, you pass a class path to your custom field
            'picture' => PictureField::class
        ];
    }

}

加载关联关系

传递给 query 的 resolve 方法的第三个参数是 GraphQL\Type\Definition\ResolveInfo 的实例, 允许你从请求中取回指定的 key. 下面是一个使用这个参数的例子来获取关联模型的数据. 如下

namespace App\GraphQL\Query;

use GraphQL;
use GraphQL\Type\Definition\Type;
use GraphQL\Type\Definition\ResolveInfo;
use Folklore\GraphQL\Support\Query;

use App\User;

class UsersQuery extends Query
{
    protected $attributes = [
        'name' => 'Users query'
    ];

    public function type()
    {
        return Type::listOf(GraphQL::type('user'));
    }

    public function args()
    {
        return [
            'id' => ['name' => 'id', 'type' => Type::string()],
            'email' => ['name' => 'email', 'type' => Type::string()]
        ];
    }

    public function resolve($root, $args, $context, ResolveInfo $info)
    {
        $fields = $info->getFieldSelection($depth = 3);

        $users = User::query();

        foreach ($fields as $field => $keys) {
            if ($field === 'profile') {
                $users->with('profile');
            }

            if ($field === 'posts') {
                $users->with('posts');
            }
        }

        return $users->get();
    }
}

你的 UserType 可能看起来是这个样子的

<?php

namespace App\GraphQL\Type;

use Folklore\GraphQL\Support\Facades\GraphQL;
use GraphQL\Type\Definition\Type;
use Folklore\GraphQL\Support\Type as GraphQLType;

class UserType extends GraphQLType
{
    /**
     * @var array
     */
    protected $attributes = [
        'name' => 'User',
        'description' => 'A user',
    ];

    /**
     * @return array
     */
    public function fields()
    {
        return [
            'uuid' => [
                'type' => Type::nonNull(Type::string()),
                'description' => 'The uuid of the user'
            ],
            'email' => [
                'type' => Type::nonNull(Type::string()),
                'description' => 'The email of user'
            ],
            'profile' => [
                'type' => GraphQL::type('Profile'),
                'description' => 'The user profile',
            ],
            'posts' => [
                'type' => Type::listOf(GraphQL::type('Post')),
                'description' => 'The user posts',
            ]
        ];
    }
}

这样我们有一个 profile 和一个 post 类型作为期待的返回关联关系数据

class ProfileType extends GraphQLType
{
    protected $attributes = [
        'name' => 'Profile',
        'description' => 'A user profile',
    ];

    public function fields()
    {
        return [
            'name' => [
                'type' => Type::string(),
                'description' => 'The name of user'
            ]
        ];
    }
}

class PostType extends GraphQLType
{
    protected $attributes = [
        'name' => 'Post',
        'description' => 'A post',
    ];

    public function fields()
    {
        return [
            'title' => [
                'type' => Type::nonNull(Type::string()),
                'description' => 'The title of the post'
            ],
            'body' => [
                'type' => Type::string(),
                'description' => 'The body the post'
            ]
        ];
    }
}

最后你的查询可能是这个样子, 使用 URL

http://homestead.app/graphql?query=query+FetchUsers{users{uuid, email, team{name}}}

[译+] Laravel GraphQL ReadMe 文档

使用

语法 / Schemas

创建查询

创建修改

添加修改验证

高级用法

查询变量

查询嵌入资源

枚举

接口

自定义字段

加载关联关系

多厘

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