[译+] Laravel GraphQL ReadMe 文档

摘要：原文地址使用语法从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。

原文地址:

readme.md

advanced.md

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" => "AppGraphQLQueryUsersQuery"
        ],
        "mutation" => [
            //"updateUserEmail" => "AppGraphQLQueryUpdateUserEmailMutation"
        ]
    ],
    "secret" => [
        "query" => [
            //"users" => "AppGraphQLQueryUsersQuery"
        ],
        "mutation" => [
            //"updateUserEmail" => "AppGraphQLQueryUpdateUserEmailMutation"
        ]
    ]
]

或者可以使用 facade 来添加语法

GraphQL::addSchema("secret", [
    "query" => [
        "users" => "AppGraphQLQueryUsersQuery"
    ],
    "mutation" => [
        "updateUserEmail" => "AppGraphQLQueryUpdateUserEmailMutation"
    ]
]);

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" => "AppGraphQLQueryUsersQuery"
    ],
    "mutation" => [
        //"updateUserEmail" => "AppGraphQLQueryUpdateUserEmailMutation"
    ]
]);

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}}

首先你需要创建一个类型

namespace AppGraphQLType;

use GraphQLTypeDefinitionType;
use FolkloreGraphQLSupportType 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" => "AppGraphQLTypeUserType"
]

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

GraphQL::addType("AppGraphQLTypeUserType", "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 AppGraphQLQuery;

use GraphQL;
use GraphQLTypeDefinitionType;
use FolkloreGraphQLSupportQuery;
use AppUser;

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" => "AppGraphQLQueryUsersQuery"
        ],
        // ...
    ]
]

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}}

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 AppGraphQLMutation;

use GraphQL;
use GraphQLTypeDefinitionType;
use FolkloreGraphQLSupportMutation;
use AppUser;

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" => "AppGraphQLMutationUpdateUserPasswordMutation"
        ],
        // ...
    ]
]

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}}

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 AppGraphQLMutation;

use GraphQL;
use GraphQLTypeDefinitionType;
use FolkloreGraphQLSupportMutation;
use AppUser;

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."
        ]
      }
    }
  ]
}

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"}

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;
}

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

 "Episode",
        "description" => "The types of demographic elements",
        "values" => [
            "NEWHOPE" => "NEWHOPE",
            "EMPIRE" => "EMPIRE",
            "JEDI" => "JEDI",
        ],
    ];
}

注册 Enum 在 config/graphql.php 的 types 数组

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

然后如下使用

 [
                "type" => GraphQL::type("TestEnum")
            ]
        ]
   }
}

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

 "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

 "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")
        ];
    }
}

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 AppGraphQLFields;

use GraphQLTypeDefinitionType;
use FolkloreGraphQLSupportField;

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 AppGraphQLType;

use GraphQLTypeDefinitionType;
use FolkloreGraphQLSupportType as GraphQLType;

use AppGraphQLFieldsPictureField;

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
        ];
    }

}

传递给 query 的 resolve 方法的第三个参数是 GraphQLTypeDefinitionResolveInfo 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 AppGraphQLQuery;

use GraphQL;
use GraphQLTypeDefinitionType;
use GraphQLTypeDefinitionResolveInfo;
use FolkloreGraphQLSupportQuery;

use AppUser;

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

 "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}}}