Apollo / GraphQL basics

location.graphql

type Location implements Resource {
  # Primary key
  id: ID!
  # Google's name for the Location
  googleName: String!
  # Google's ID for the Location
  googleId: ID!
  # Google's Place ID for the Location
  googlePlaceId: ID!
  # Google's Timezone ID for the Location
  googleTimezoneId: ID
  # Google's Timezone name for the Location
  googleTimezoneName: String
  # Google's Timezone DST offset for the Location
  googleTimezoneDstOffset: Int
  # Google's Timezone raw offset for the Location
  googleTimezoneRawOffset: Int
  # Google's Url<GoogleIcon> for the Location
  googleIcon: Url
  # Google's latitude coordinate for the Location
  googleCoordLat: Float
  # Google's longitude coordinate for the Location
  googleCoordLng: Float
}

mutation.graphql

type Mutation {
  # Logs in an Existing user object
  loginUser (
    # LoginUserInput to log in a user via login
    user: UserLoginInput!
  ): User # Returns a User...
}

sampleLoginQuery.graphql

mutation loginUser($user: UserLoginInput!){
  user: loginUser(user: $user) {
  	id
    name
    email
    CurrentLocation (home: true) {
      id
      googleName
      googlePlaceId
    }
  }
}

user.graphql

type User {
  # Primary key
  id: ID!
  # The User's name
  name: String!

  # The Location<Current> attached to the User
  CurrentLocation: Location
}


# Used to login an existing User object.
input UserLoginInput {
  # The User's email
  email: Email
  # THe User's password
  password: String
}

userResolver.js

const loginUser = async (root, { user: { email, password } }, context) => {
  const { models: { User } } = context; // You can attach your Models to the context in Apollo's configuration function
  const { user, token } = await User.login({ email, password });
  if (!user) throw new LoginFailedError();
  context.user = user; //attach user to context for subsequent edges etc
  return user;
}

export default {
  Mutation: {
    loginUser // Maps to loginUser in the mutation definition
  },
  User: { 
    // Here, we define edges for the User type. 
    // GraphQL knows that the Login mutation returns a User because of the schema definition
    // says so
    
    // CurrentLocation is listed in the User schema as being of type Location
    // Like every resolver, our edge resolver receives 3 props
    // 1) Root - The node that we are coming from.  In the case
    //           that we just logged in and are attempting to fetch
    //           the CurrentLocation of the User in the mutation query,
    //           Root will be the user returned from the Login resolver above
    // 2) Args - The arguments specific to this part of the query.  For instance, if we did:
    //           In this case, according to the sample login request below, the args are { home: true }
    // 2) Context - A mutable "local" context passed through to all resolvers from Apollo for each request.
    CurrentLocation: (user, args, context) => user.getCurrentLocation() // SequelizeJS association getter
  }
}