graphql/type
graphql/type
模块负责定义 GraphQL 类型和结构。你可以从 graphql/type
模块或根 graphql
模块导入。例如:
¥The graphql/type
module is responsible for defining GraphQL types and schema. You can import either from the graphql/type
module, or from the root graphql
module. For example:
import { GraphQLSchema } from "graphql" // ES6
var { GraphQLSchema } = require("graphql") // CommonJS
概述
¥Overview
结构
¥Schema
定义
¥Definitions
class GraphQLScalarType
A scalar type within GraphQL.class GraphQLObjectType
An object type within GraphQL that contains fields.class GraphQLInterfaceType
An interface type within GraphQL that defines fields implementations will contain.class GraphQLUnionType
A union type within GraphQL that defines a list of implementations.class GraphQLEnumType
An enum type within GraphQL that defines a list of valid values.class GraphQLInputObjectType
An input object type within GraphQL that represents structured inputs.class GraphQLList
A type wrapper around other types that represents a list of those types.class GraphQLNonNull
A type wrapper around other types that represents a non-null version of those types.
谓词
¥Predicates
function isInputType
Returns if a type can be used as input types for arguments and directives.function isOutputType
Returns if a type can be used as output types as the result of fields.function isLeafType
Returns if a type can be a leaf value in a response.function isCompositeType
Returns if a type can be the parent context of a selection set.function isAbstractType
Returns if a type is a combination of object types.
Un-modifiers
function getNullableType
Strips any non-null wrappers from a type.function getNamedType
Strips any non-null or list wrappers from a type.
标量
¥Scalars
var GraphQLInt
A scalar type representing integers.var GraphQLFloat
A scalar type representing floats.var GraphQLString
A scalar type representing strings.var GraphQLBoolean
A scalar type representing booleans.var GraphQLID
A scalar type representing IDs.
结构
¥Schema
GraphQLSchema
class GraphQLSchema {
constructor(config: GraphQLSchemaConfig)
}
type GraphQLSchemaConfig = {
query: GraphQLObjectType;
mutation?: GraphQLObjectType;
}
通过提供每种类型的操作、查询和变更(可选)的根类型来创建结构。然后将结构定义提供给验证器和执行器。
¥A Schema is created by supplying the root types of each type of operation, query and mutation (optional). A schema definition is then supplied to the validator and executor.
示例
¥Example
var MyAppSchema = new GraphQLSchema({
query: MyAppQueryRootType,
mutation: MyAppMutationRootType
});
定义
¥Definitions
GraphQLScalarType
class GraphQLScalarType<InternalType> {
constructor(config: GraphQLScalarTypeConfig<InternalType>)
}
type GraphQLScalarTypeConfig<InternalType> = {
name: string;
description?: string;
serialize: (value: mixed) => InternalType;
parseValue?: (value: mixed) => InternalType;
parseLiteral?: (valueAST: Value) => InternalType;
}
任何请求的叶值和参数的输入值都是标量(或枚举),并使用名称和一系列用于确保有效性的序列化函数进行定义。
¥The leaf values of any request and input values to arguments are Scalars (or Enums) and are defined with a name and a series of serialization functions used to ensure validity.
示例
¥Example
var OddType = new GraphQLScalarType({
name: "Odd",
serialize: oddValue,
parseValue: oddValue,
parseLiteral(ast) {
if (ast.kind === Kind.INT) {
return oddValue(parseInt(ast.value, 10))
}
return null
}
})
function oddValue(value) {
return value % 2 === 1 ? value : null
}
GraphQLObjectType
class GraphQLObjectType {
constructor(config: GraphQLObjectTypeConfig)
}
type GraphQLObjectTypeConfig = {
name: string;
interfaces?: GraphQLInterfacesThunk | GraphQLInterfaceType[];
fields: GraphQLFieldConfigMapThunk | GraphQLFieldConfigMap;
isTypeOf?: (value: any, info?: GraphQLResolveInfo) => boolean;
description?: string
}
type GraphQLInterfacesThunk = () => Array<GraphQLInterfaceType>;
type GraphQLFieldConfigMapThunk = () => GraphQLFieldConfigMap;
// See below about resolver functions.
type GraphQLFieldResolveFn = (
source?: any,
args?: {[argName: string]: any},
context?: any,
info?: GraphQLResolveInfo
) => any
type GraphQLResolveInfo = {
fieldName: string,
fieldNodes: Array<Field>,
returnType: GraphQLOutputType,
parentType: GraphQLCompositeType,
schema: GraphQLSchema,
fragments: { [fragmentName: string]: FragmentDefinition },
rootValue: any,
operation: OperationDefinition,
variableValues: { [variableName: string]: any },
}
type GraphQLFieldConfig = {
type: GraphQLOutputType;
args?: GraphQLFieldConfigArgumentMap;
resolve?: GraphQLFieldResolveFn;
deprecationReason?: string;
description?: string;
}
type GraphQLFieldConfigArgumentMap = {
[argName: string]: GraphQLArgumentConfig;
};
type GraphQLArgumentConfig = {
type: GraphQLInputType;
defaultValue?: any;
description?: string;
}
type GraphQLFieldConfigMap = {
[fieldName: string]: GraphQLFieldConfig;
};
你定义的几乎所有 GraphQL 类型都是对象类型。对象类型有一个名称,但最重要的是描述它们的字段。
¥Almost all of the GraphQL types you define will be object types. Object types have a name, but most importantly describe their fields.
当两种类型需要相互引用,或者一个类型需要在字段中引用自身时,你可以使用函数表达式(也称为闭包或 thunk)来延迟提供字段。
¥When two types need to refer to each other, or a type needs to refer to itself in a field, you can use a function expression (aka a closure or a thunk) to supply the fields lazily.
请注意,解析器函数提供 source
对象作为第一个参数。但是,如果未提供解析器函数,则使用默认解析器,该解析器在 source
上查找与字段同名的方法。如果找到,则使用 (args, context, info)
调用该方法。由于它是 source
上的方法,因此该值始终可以用 this
引用。
¥Note that resolver functions are provided the source
object as the first parameter.
However, if a resolver function is not provided, then the default resolver is
used, which looks for a method on source
of the same name as the field. If found,
the method is called with (args, context, info)
. Since it is a method on source
,
that value can always be referenced with this
.
示例
¥Examples
var AddressType = new GraphQLObjectType({
name: "Address",
fields: {
street: { type: GraphQLString },
number: { type: GraphQLInt },
formatted: {
type: GraphQLString,
resolve(obj) {
return obj.number + " " + obj.street
}
}
}
})
var PersonType = new GraphQLObjectType({
name: "Person",
fields: () => ({
name: { type: GraphQLString },
bestFriend: { type: PersonType }
})
})
GraphQLInterfaceType
class GraphQLInterfaceType {
constructor(config: GraphQLInterfaceTypeConfig)
}
type GraphQLInterfaceTypeConfig = {
name: string,
fields: GraphQLFieldConfigMapThunk | GraphQLFieldConfigMap,
resolveType?: (value: any, info?: GraphQLResolveInfo) => GraphQLObjectType,
description?: string
};
当一个字段可以返回一组异构类型中的一个时,接口类型用于描述哪些类型是可能的,哪些字段在所有类型中是通用的,以及一个函数来确定当字段被返回时实际使用哪种类型。 解决。
¥When a field can return one of a heterogeneous set of types, a Interface type is used to describe what types are possible, what fields are in common across all types, as well as a function to determine which type is actually used when the field is resolved.
示例
¥Example
var EntityType = new GraphQLInterfaceType({
name: "Entity",
fields: {
name: { type: GraphQLString }
}
})
GraphQLUnionType
class GraphQLUnionType {
constructor(config: GraphQLUnionTypeConfig)
}
type GraphQLUnionTypeConfig = {
name: string,
types: GraphQLObjectsThunk | GraphQLObjectType[],
resolveType?: (value: any, info?: GraphQLResolveInfo) => GraphQLObjectType;
description?: string;
};
type GraphQLObjectsThunk = () => GraphQLObjectType[];
当字段可以返回一组异构类型之一时,联合类型用于描述可能的类型,并提供一个函数来确定解析字段时实际使用哪种类型。
¥When a field can return one of a heterogeneous set of types, a Union type is used to describe what types are possible as well as providing a function to determine which type is actually used when the field is resolved.
示例
¥Example
var PetType = new GraphQLUnionType({
name: "Pet",
types: [DogType, CatType],
resolveType(value) {
if (value instanceof Dog) {
return DogType
}
if (value instanceof Cat) {
return CatType
}
},
})
GraphQLEnumType
class GraphQLEnumType {
constructor(config: GraphQLEnumTypeConfig)
}
type GraphQLEnumTypeConfig = {
name: string;
values: GraphQLEnumValueConfigMap;
description?: string;
}
type GraphQLEnumValueConfigMap = {
[valueName: string]: GraphQLEnumValueConfig;
};
type GraphQLEnumValueConfig = {
value?: any;
deprecationReason?: string;
description?: string;
}
type GraphQLEnumValueDefinition = {
name: string;
value?: any;
deprecationReason?: string;
description?: string;
}
请求和输入值的一些叶值是枚举。GraphQL 将 Enum 值序列化为字符串,但在内部 Enum 可以用任何类型(通常是整数)表示。
¥Some leaf values of requests and input values are Enums. GraphQL serializes Enum values as strings, however internally Enums can be represented by any kind of type, often integers.
注意:如果定义中未提供值,则枚举值的名称将用作其内部值。
¥Note: If a value is not provided in a definition, the name of the enum value will be used as its internal value.
示例
¥Example
var RGBType = new GraphQLEnumType({
name: "RGB",
values: {
RED: { value: 0 },
GREEN: { value: 1 },
BLUE: { value: 2 },
},
})
GraphQLInputObjectType
class GraphQLInputObjectType {
constructor(config: GraphQLInputObjectConfig)
}
type GraphQLInputObjectConfig = {
name: string;
fields: GraphQLInputObjectConfigFieldMapThunk | GraphQLInputObjectConfigFieldMap;
description?: string;
}
type GraphQLInputObjectConfigFieldMapThunk = () => GraphQLInputObjectConfigFieldMap;
type GraphQLInputObjectFieldConfig = {
type: GraphQLInputType;
defaultValue?: any;
description?: string;
}
type GraphQLInputObjectConfigFieldMap = {
[fieldName: string]: GraphQLInputObjectFieldConfig;
};
type GraphQLInputObjectField = {
name: string;
type: GraphQLInputType;
defaultValue?: any;
description?: string;
}
type GraphQLInputObjectFieldMap = {
[fieldName: string]: GraphQLInputObjectField;
};
输入对象定义可以提供给字段参数的结构化字段集合。
¥An input object defines a structured collection of fields which may be supplied to a field argument.
使用 NonNull
将确保查询必须提供一个值
¥Using NonNull
will ensure that a value must be provided by the query
示例
¥Example
var GeoPoint = new GraphQLInputObjectType({
name: "GeoPoint",
fields: {
lat: { type: new GraphQLNonNull(GraphQLFloat) },
lon: { type: new GraphQLNonNull(GraphQLFloat) },
alt: { type: GraphQLFloat, defaultValue: 0 },
},
})
GraphQLList
class GraphQLList {
constructor(type: GraphQLType)
}
列表是一种类型标记,是指向另一种类型的封装类型。列表通常是在定义对象类型的字段的上下文中创建的。
¥A list is a kind of type marker, a wrapping type which points to another type. Lists are often created within the context of defining the fields of an object type.
示例
¥Example
var PersonType = new GraphQLObjectType({
name: "Person",
fields: () => ({
parents: { type: new GraphQLList(PersonType) },
children: { type: new GraphQLList(PersonType) },
}),
})
GraphQLNonNull
class GraphQLNonNull {
constructor(type: GraphQLType)
}
非空是一种类型标记,是指向另一种类型的封装类型。非空类型强制其值永远不为空,并且可以确保在请求期间发生这种情况时引发错误。它对于可以对非空性做出强有力保证的字段很有用,例如通常数据库行的 id 字段永远不会为空。
¥A non-null is a kind of type marker, a wrapping type which points to another type. Non-null types enforce that their values are never null and can ensure an error is raised if this ever occurs during a request. It is useful for fields which you can make a strong guarantee on non-nullability, for example usually the id field of a database row will never be null.
示例
¥Example
var RowType = new GraphQLObjectType({
name: "Row",
fields: () => ({
id: { type: new GraphQLNonNull(String) },
}),
})
谓词
¥Predicates
isInputType
function isInputType(type: GraphQLType): boolean
这些类型可以用作参数和指令的输入类型。
¥These types may be used as input types for arguments and directives.
isOutputType
function isOutputType(type: GraphQLType): boolean
这些类型可以用作字段结果的输出类型
¥These types may be used as output types as the result of fields
isLeafType
function isLeafType(type: GraphQLType): boolean
这些类型可以描述可能是叶值的类型
¥These types may describe types which may be leaf values
isCompositeType
function isCompositeType(type: GraphQLType): boolean
这些类型可以描述选择集的父上下文
¥These types may describe the parent context of a selection set
isAbstractType
function isAbstractType(type: GraphQLType): boolean
这些类型可以描述对象类型的组合
¥These types may describe a combination of object types
Un-modifiers
getNullableType
function getNullableType(type: GraphQLType): GraphQLNullableType
如果给定类型不可为空,则这会去除不可空性并返回基础类型。
¥If a given type is non-nullable, this strips the non-nullability and returns the underlying type.
getNamedType
function getNamedType(type: GraphQLType): GraphQLNamedType
如果给定类型不可为空或列表,则此重复将去除不可为空和列表封装器并返回基础类型。
¥If a given type is non-nullable or a list, this repeated strips the non-nullability and list wrappers and returns the underlying type.
标量
¥Scalars
GraphQLInt
let GraphQLInt: GraphQLScalarType
代表 int 的 GraphQLScalarType
。
¥A GraphQLScalarType
that represents an int.
GraphQLFloat
let GraphQLFloat: GraphQLScalarType
代表浮点数的 GraphQLScalarType
。
¥A GraphQLScalarType
that represents a float.
GraphQLString
let GraphQLString: GraphQLScalarType
代表字符串的 GraphQLScalarType
。
¥A GraphQLScalarType
that represents a string.
GraphQLBoolean
let GraphQLBoolean: GraphQLScalarType
代表布尔值的 GraphQLScalarType
。
¥A GraphQLScalarType
that represents a boolean.
GraphQLID
let GraphQLID: GraphQLScalarType
代表 ID 的 GraphQLScalarType
。
¥A GraphQLScalarType
that represents an ID.