我正在尝试使用与中继兼容的 GraphQL 模式设置一个节点.js服务器。
尝试验证或加载架构时，出现以下错误：
EventEdge.node field type must be Output Type but got: undefined.
这是由于在其他类型定义之一中具有 Event 类型的连接类型导致的。
我不会发布整个架构，因为它非常冗长，但是当连接字段被注释掉时，架构会正确加载并且不会抛出任何错误。
我包括了一个导致相同问题的简化架构示例：
const graphql = require('graphql')
const relay = require('graphql-relay')
const GraphQLID = graphql.GraphQLID,
GraphQLInt = graphql.GraphQLInt,
GraphQLString = graphql.GraphQLString,
GraphQLList = graphql.GraphQLList,
GraphQLObjectType = graphql.GraphQLObjectType,
GraphQLSchema = graphql.GraphQLSchema,
GraphQLNonNull = graphql.GraphQLNonNull
const connectionArgs = relay.connectionArgs,
connectionDefinitions = relay.connectionDefinitions,
connectionFromArray = relay.connectionFromArray,
cursorForObjectInConnection = relay.cursorForObjectInConnection,
fromGlobalId = relay.fromGlobalId,
globalIdField = relay.globalIdField,
mutationWithClientMutationId = relay.mutationWithClientMutationId,
nodeDefinitions = relay.nodeDefinitions,
toGlobalId = relay.toGlobalId
// Models (ORM Mappings)
const models = require('../models')
// Model handlers
const handlers = require('../models/handlers')
/*
* Relay Node Definition:
* {nodeInterface, nodeField} = nodeDefinitions
*/
var nodeDefinition = nodeDefinitions(
(globalId) => {
// {type, id} = fromGlobalId(globalId)
const gid = fromGlobalId(globalId);
switch (gid.type) {
case 'User':
return handlers.getUser(id)
// case 'Event':
// return handlers.getEvent(id)
//
// case 'Club':
// return handlers.getClub(id)
default:
return null
}
},
(obj) => {
switch (true) {
case (obj instanceof models.User):
return UserType
// case (obj instanceof models.Club):
// return ClubType
//
// case (obj instanceof models.Event):
// return EventType
default:
return null
}
}
)
/**************************
**************************
* Relay Connections
*
* { connectionType, edgeType } = connectionDefinitions({nodeType: LoremType})
**************************
**************************/
// User Connection
// const usersConnection = connectionDefinitions({name: 'User', nodeType: UserType})
// Event Connection
const eventsConnection = connectionDefinitions({name: 'Event', nodeType: EventType})
// Club Connection
// const clubsConnection = connectionDefinitions({name: 'Club', nodeType: ClubType})
/**************************
**************************
* GraphQL Type Definitions
**************************
**************************/
/*
* User Type
*
* type User : Object {
* id: String!
* first_name: String
* last_name: String
* friends: [User]
* }
*/
var UserType = new GraphQLObjectType({
name: 'User',
description: 'A user of the app.',
fields: () => ({
id: globalIdField('User'),
events: {
type: eventsConnection.connectionType,
description: 'User's events.',
args: connectionArgs,
resolve: (user, args) => connectionFromArray(getEvents(), args)
}
}),
interfaces: [nodeDefinition.nodeInterface]
})
/*
** Event Type
*
* type Event : Object {
* id: String!
* title: String
* description: String
* datetime: Int
* location: [Int]
* managers: [User]
* club: Club
* members: [User]
* }
*/
var EventType = new GraphQLObjectType({
name: 'Event',
description: 'An event in the app.',
fields: () => ({
id: globalIdField('Event'),
name: {
type: GraphQLString,
description: 'Event's name.',
resolve: event => event.get('name')
}
}),
interfaces: [nodeDefinition.nodeInterface]
})
/****************************
****************************
* Relay Mutation Definitions
****************************
****************************/
/**************************
**************************
* Root Schema Definitions
**************************
**************************/
/*
** Root Query
*
* type Query {
* user(id: String!): User
* club(id: String!): Club
* event(id: String!): Event
* }
*/
var QueryType = new GraphQLObjectType({
name: 'Query',
fields: () => ({
node: nodeDefinition.nodeField,
user: {
type: UserType,
resolve: () => handlers.getUser()
}
})
})
/*
** Root Schema
*
* type Schema {
* query: Query
* mutation: Mutation
* }
*/
var Schema = new GraphQLSchema({
query: QueryType
})
module.exports = Schema
在分配给EventType之前，您已经引用了它。首先定义类型，然后在连接中使用它：
/**
* Event Type
*
* type Event : Object {
* id: String!
* title: String
* description: String
* datetime: Int
* location: [Int]
* managers: [User]
* club: Club
* members: [User]
* }
*/
var EventType = new GraphQLObjectType({
name: 'Event',
description: 'An event in the app.',
fields: () => ({
id: globalIdField('Event'),
name: {
type: GraphQLString,
description: 'Event's name.',
resolve: event => event.get('name')
},
}),
interfaces: [nodeDefinition.nodeInterface],
});
// Event Connection
const eventsConnection = connectionDefinitions({
name: 'Event',
nodeType: EventType,
});