EcoSystem|Graphql-binding

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🔗 graphql-binding 可以在 graphql server 中嵌入grahql API
核心概念是通过为 GraphQL API 创建一个对象,表现出 API 的功能. 这个对象暴露的方法和GraphQL API schema 中定义的查询方法是镜像关系.

Install

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yarn add graphql-binding

API

constructor

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constructor(options: BindingOptions): Binding
Key Required Type Default Note
schema Yes GraphQLSchema - The executable GraphQL schema for binding
fragmentReplacements No FragmentReplacements {} A list of GraphQL fragment definitions, specifying fields that are required for the resolver to function correctly
before No () => void (() => undefined) A function that will be executed before a query/mutation is sent to the GraphQL API
handler No any null The handler object from JS Proxy
subscriptionHandler No any null …

query&mutation

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binding.query.<rootField>: QueryMap<any> // where <rootField> is the name of a field on the Query type in the mapped GraphQL schema
binding.mutation.<rootField>: QueryMap<any> // where <rootField> is the name of a field on the Mutation type in the mapped GraphQL schema

binding对象暴露出两个接口 query,mutate可以用于执行操作.分别接收三个参数

实例

假设有下面的 schema

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type Query {
  user(id: ID!): User
}

type Mutation {
  createUser(): User!
}
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binding.query.user({ id: 'abc' })
binding.mutation.createUser()
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findUser(parent, args, context, info) {
  return binding.user({ id: args.id }, context, info)
}

newUser(parent, args, context, info) {
  return binding.createUser({}, context, info)
}
subscription
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binding.subscription.<rootField>(...):  AsyncIterator<any> | Promise<AsyncIterator<any>> 
// where <rootField> is the name of a field 
//on the Subscription type in the mapped GraphQL schema

简单实例

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const { makeExecutableSchema } = require('graphql-tools')
const { Binding } = require('graphql-binding')

const users = [
  {
    name: 'Alice',
  },
  {
    name: 'Bob',
  },
]

const typeDefs = `
  type Query {
    findUser(name: String!): User
  }
  type User {
    name: String!
  }
`

const resolvers = {
  Query: {
    findUser: (parent, { name }) => users.find(u => u.name === name),
  },
}

const schema = makeExecutableSchema({ typeDefs, resolvers })

const findUserBinding = new Binding({
  schema,
})

findUserBinding.findUser({ name: 'Bob' })
  .then(result => console.log(result))

与 Prisma 的联系

graphcool-binding(prisma) 是这个版本的实现方案

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// Instantiate `Prisma` based on concrete service
const prisma = new Prisma({
  typeDefs: 'schemas/database.graphql',
  endpoint: 'https://us1.prisma.sh/demo/my-service/dev'
  secret: 'my-super-secret-secret'
})

// Retrieve `name` of a specific user
prisma.query.user({ where { id: 'abc' } }, '{ name }')

// Retrieve `id` and `name` of all users
prisma.query.users(null, '{ id name }')

// Create new user called `Sarah` and retrieve the `id`
prisma.mutation.createUser({ data: { name: 'Sarah' } }, '{ id }')

// Update name of a specific user and retrieve the `id`
prisma.mutation.updateUser({ where: { id: 'abc' }, data: { name: 'Sarah' } }, '{ id }')

// Delete a specific user and retrieve the `name`
prisma.mutation.deleteUser({ where: { id: 'abc' } }, '{ id }')

内部机制

prisma 的函数调用最终翻译为 graphql-binding 的方式

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prisma.exists.Post({
  id: 'abc',
  author: {
    name: 'Sarah'
  }
})