Getting Started with Hello World Data Sync

In this example, you add the Voyager Server library to your Express node.js project, create an index-1.js file, run the server, and query GraphQL.

  • Voyager Server is a set of Node.js libraries that can be used to build a Data Sync server.

  • Voyager Server is the starting point for developing a Data Sync application.

Prerequisites

  • You have Node.js and npm installed.

  • You have created a node.js project.

Procedure

  1. Add libraries to your Node.js application:

    $ npm install graphql (1)
$ npm install express (2)
$ npm install @aerogear/voyager-server (3)
    1 See https://graphql.org/
    2 See https://expressjs.com/
    3 The Voyager Server library that enables data sync

  2. Create an index-1.js file with the following content:

    const express = require('express')
//Include our server libraries
const { VoyagerServer, gql } = require('@aerogear/voyager-server')

//Provide your graphql schema
const typeDefs = gql`
  type Query {
    hello: String
  }
`

//Create the resolvers for your schema
const resolvers = {
  Query: {
    hello: (obj, args, context, info) => {
      return `Hello world`
    }
  }
}

//Initialize the library with your Graphql information
const apolloServer = VoyagerServer({
  typeDefs,
  resolvers
})

//Connect the server to express
const app = express()
apolloServer.applyMiddleware({ app })

app.listen(4000, () =>
  console.log(`🚀 Server ready at http://localhost:4000/graphql`)
)

  3. Run the server:

    $ node index-1.js

🚀 Server ready at http://localhost:4000/graphql

  4. Browse http://localhost:4000/graphql and interact with the playground. For example:

    {
  hello
}

  5. Check the output. For the example above, the output should be:

    {
  "data": {
    "hello": "Hello world"
  }
}

To get started with the Data Sync framework, see the sample application. In this app, you can explore a more complex schema.

Before proceeding, make sure you have an understanding of the following GraphQL concepts:

  • Schema design

  • Resolvers

  • Subscriptions