GraphQL Tutorial

GraphQL is gaining traction these days as a RESTful replacement for Mobile native applications and Single Page Applications built on top of React, Vue, and Angular. It is designed to resolve common issues with RESTful API, and has a lot of wonderful features; however, for most developers it is very hard to learn in the first place. In this section, we are going to walk through several light-graphql-4j examples and show you how to build your own GraphQL server.

There are several tutorials, and source code can be found at light-example-4j graphql folder.

Hello World

This is a very simple Hello World query to show you how to get GraphQL up and running with light-codegen without using GraphQL IDL.

Star Wars

This is a similar example to Hello World with IDL to trigger the generation. It utilizes the star wars GraphQL IDL downloaded from the Internet.

Mutation

This example shows you how to create a full-blown GraphQL service with both query and mutation.

Mutation IDL

This is the same example as the mutation but is generated from a schema.

Relay Todo

This is to show you how to build a GraphQL service that is working with Relayjs.

Subscription

This is to show you how to build a GraphQL service with subscriptions.

GraphQL Subscription

A client to server integration pattern over websockets using graphql queries. Read More »

Starwars Tutorial

This tutorial is very similar to Hello World. The only difference is that this one has been generated from the star wars schema. Schema is defined in a file with extension .graphqls and the schema used in this project can be found at https://github.com/networknt/model-config/blob/master/graphql/starwars/schema.graphqls Here is the content of the schema. schema { query: QueryType } type QueryType { hero(episode: Episode): Character human(id : String) : Human droid(id: ID!): Droid } enum Episode { NEWHOPE EMPIRE JEDI } interface Character { id: ID! Read More »

Relay Todo Tutorial

In this tutorial, we are going to port the Relay TodoMVC example where the GraphQL server is replaced with light-graphql-4j. Let’s build this from mutation example and make some modifications. Backup and Copy First let’s backup the existing relaytodo in light-example-4j/graphql folder and rebuild using the same folder name. We can always compare the .bak folder to see if we have missed something. cd ~/networknt git clone https://github.com/networknt/light-example-4j.git cd light-example-4j/graphql mv relaytodo relaytodo. Read More »

Mutation Tutorial with IDL

In the mutation tutorial, we have created a new project by copying and modifying the hello world tutorial. In this tutorial, we are going to generate the project from IDL and change it accordingly. Users can compare between these two implementations and see the difference. It helps users to understand that in which case to copy an existing project and create the schema or create the schema first and generate the project from it. Read More »

Mutation Tutorial

The Mutation is modified from hello world example, and some of the files are updated. The first step is to make a copy of the helloworld example in light-example-4j, and then we can update several files to have a new schema and wired in the business logic. Prepare environment First, we need to clone light-codegen, model-config, and light-example-4j into your workspace. I am using networknt as workspace in my home directory. Read More »

Hello World Tutorial

Like light-rest-4j we have light-codegen to generate a project from either Swagger 2.0 or OpenAPI 3.0 specification, we can generate GraphQL project from GraphQL IDL. Or generate without providing any model. For this Hello World example, we are going to generate it with only a config.json. Prepare environment First, we need to clone light-codegen, model-config, and light-example-4j into your workspace. I am using networknt as workspace in my home directory. Read More »