GraphQL

NODE

Category

1. GraphQL
2. jsonwebtoken
3. redux server render
4. HOC && recompose

What is GraphQL

1. A query language for your API

GraphQL provides a complete and understandable description of the data in your API

3. Get exactly what you need

// before
{
    person {
        name
        email
    }
}
// data
{
    "person": {
        "name": "ybduan",
        "email": "ybduan@corp.netease.com"
    }
}
// after
{
    person {
        name
    }
}
// data
{
    "person": {
        "name": "ybduan"
    }
}

4. Get many resources in a single request

// query
{
    person {
        name
        posts {
            title
        }
    }
}
// result
{
    "person": {
        "name": "ybduan",
        "posts": [{
            "title": "This is title"
        }, {
            "title": "This is another title"
        }]
    }
}

5. Type system

// query
{
    person {
        name
        posts {
            title
        }
    }
}
//
type person {
    name: String!
    email: String
    posts: [Post]
}
type Post {
    title: String
    content: String
}

6. No versions

Add new fields and types to your GraphQL API without impacting existing queries

How to do

1. Describe your data

// Define type
type Person {
  name: String
  email: String
  posts: [Post]
}
type Query {
    person(name: String): Person
}
// Define resolver
const resolverFunctions = {
    Query: {
        async person(_, args, context) {
            return await DB.model('person').find({ where: { name: args.name })
        }
    },
    Person: {
        async posts(person, args, context) {
            return await person.getPosts()
        }
    }
}

2. Ask for what you want

{
  person(name: "ybduan") {
    email
  }
}

3. Get predictable results

{
    "person": {
        "email": "ybduan@corp.netease.com"
    }
}

Troubleshootings

Business Logic Layer

Where to perform validation and authorization checks

Authorization

const resolveFunctions = {
  Person: {
    posts(person, args, context = {}) {
      // return person.getPosts()
      const where = (context.authToken && person.id === context.authToken.id) ? null : { outward: true }
      return person.getPosts({ where }).then((data) => {
        return data
      })
    }
  }
}