cometd

The CometD Project

Welcome to the CometD Project, a scalable comet (server push) and websocket messaging library for the web.

This repository mirrors the JavaScript sources hosted at the main CometD repository. Those JavaScript sources are not suitable to be consumed with NPM, and are therefore re-arranged in this repository for to make it simpler to use CometD with NPM.

Versions

• 8.0.x ⇒ based on CometD 8.0.x - full ECMAScript 6 (modules, classes, let, const, arrow functions)
• 7.0.x ⇒ based on CometD 7.0.x - minimal ECMAScript 6 (let, const and arrow functions)
• 6.0.x ⇒ N/A
• 5.0.x ⇒ based on CometD 5.0.x - minimal ECMAScript 5 (var everywhere)

Version 6.0.x is not released to NPM since it's identical to 7.0.x.
The 6.0.x numbering exists only because the main CometD project, on the server side, is different from 7.0.x, but on the client side there is no difference.

License

The CometD source code is released under the Apache 2.0 License.

NPM Installation

npm install cometd

ES6 Usage

// Import the CometD symbols.
import {CometD} from "./cometd/cometd.js";
import {TimeStampExtension} from "./cometd/TimeStampExtension.js";

// Create the CometD object.
const cometd = new CometD();

// Optionally, register an extension.
cometd.registerExtension("timestamp", new TimeStampExtension());

// Configure the CometD object.
cometd.configure({
    url: "http://host/cometd"
});

// Handshake with the server.
cometd.handshake((reply) => {
    if (reply.successful) {
        // Subscribe to receive messages from the server.
        cometd.subscribe("/topic", (message) => {
            const dataFromServer = message.data;
            // Use dataFromServer.
        });
    }
});