const express = require('express')
const { graphqlHTTP } = require("express-graphql");
const {
GraphQLSchema,
GraphQLObjectType,
GraphQLString,
GraphQLList,
GraphQLInt,
GraphQLNonNull
} = require('graphql')
const app = express()
const port = 3000
// Sample Data
const authors = [
{ id: 1, name: 'Dan Brown' },
{ id: 2, name: 'J. R. R. Tolkien' },
{ id: 3, name: 'Brent Weeks' }
]
const books = [
{ id: 1, name: 'The Lost Symbol', authorId: 1 },
{ id: 2, name: 'Angels and Demons', authorId: 1 },
{ id: 3, name: 'The Davinci Code', authorId: 1 },
{ id: 4, name: 'The Fellowship of the Ring', authorId: 2 },
{ id: 5, name: 'The Two Towers', authorId: 2 },
{ id: 6, name: 'The Return of the King', authorId: 2 },
{ id: 7, name: 'The Way of Shadows', authorId: 3 },
{ id: 8, name: 'Beyond the Shadows', authorId: 3 }
]
const BookType = new GraphQLObjectType({
name: 'Book',
description: 'This represents a book written by an author',
fields: () => ({
id: { type: GraphQLNonNull(GraphQLInt) },
name: { type: GraphQLNonNull(GraphQLString) },
authorId: { type: GraphQLNonNull(GraphQLInt) },
author: {
type: AuthorType, // AuthorType is defined below the same way that BookType is defined above
resolve: (book) => {
return authors.find(author => author.id === book.authorId)
}
}
})
})
const AuthorType = new GraphQLObjectType({
name: 'Author',
description: 'This represents the author of a book',
fields: () => ({
id: { type: GraphQLNonNull(GraphQLInt) },
name: { type: GraphQLNonNull(GraphQLString) }
})
})
const RootQueryType = new GraphQLObjectType({
name: 'Query',
description: 'Root Query',
fields: () => ({
books: {
type: new GraphQLList(BookType),
description: "List of books",
resolve: () => books
}
})
})
const schema = new GraphQLSchema({
query: RootQueryType
})
app.use('/graphql', graphqlHTTP({
schema: schema,
graphiql: true
}))
app.get('/', (req, res) => {
res.send(`<a href="http://localhost:${port}/graphql">GraphiQL</a>`)
})
// QUERY:
//
// {
// books {
// id
// name
// author {
// name
// }
// }
// }
// RESULT
//
// {
// "data": {
// "books": [
// {
// "id": 1,
// "name": "The Lost Symbol",
// "author": {
// "name": "Dan Brown"
// }
// },
// {
// "id": 2,
// "name": "Angels and Demons",
// "author": {
// "name": "Dan Brown"
// }
// }, //...
// ]
// }
// }
app.listen(port, () => {
console.log(`App listening on http://localhost:${port}`)
});
