GraphQL Web Socket

The most efficient way to access a GraphQL server is over a web socket. That's why zox.js features a back-end web socket controller and a front-end utility class that can communicate with it, both of which are called GraphQLWebSocket.

We can establish a web socket connection by instantiating the GraphQLWebSocket on the front-end.

const gql = new GraphQLWebSocket();

The default web socket endpoint is ws://${}/graphql, but if our graphql server is on a different route or a different domain we can pass the uri as the first parameter.

The GraphQLWebSocket client uses the WebSocketEx class which allows us to automatically reconnect if the connection is lost. This can be disabled by passing false as the second argument to GraphQLWebSocket.

Before using the connection we should either check if (gql.readyState == WebSocket.OPEN) or set a task to be executed once it is open:

gql.promiseOnOpen.then(() =>
    // use gql ...

We can use this connection to execute a query by calling:

// using a predefined query by it's id and operation name
const args = { id: 'posts', op: 'all', vars: {} };

// using a custom query
const argsRaw = { raw: '{ id, text, ... }', vars: {} };

gql.query(args, handleResult, onDisconnected); // send the query
gql.queryAsync(args); // promisified version

We can also use it to subscribe to events:
the arguments are the same as when sending a normal query

const sid = gql.subscribe(args, handleEvent, onDisconnected);

Previous article

Built-In Endpoints

Next article

Inner Workings