A very simple IRC web client and WebSocket bridge for SwiftNIO

SwiftNIO IRC Web Client

Swift4 Swift5 macOS tuxOS

This is a very simple WebSocket based IRC WebClient/Server.

It contains a small chat-webapp as the frontend (a single-page webapp written in plain JavaScript, not frameworks), it contains a WebSocket/IRC bridge using the SwiftNIO IRC client module, and a small HTTP server which delivers the webapp and serves as a websocket endpoint.

This WebClient is a regular Swift package and can be imported in other Swift servers!

What it looks like

On the surface it is a very simple chat webapp, with basic support for channels and direct messages:

Sometimes a live demo installation is running on http://irc.noze.io/. We probably have to shut it down once abuse starts to take place :-) If it doesn't run and you want to play with it, just install it locally, it is a matter of minutes using MiniIRCd.


Swift NIO Parts

This module contains the middlepart, the webserver. It serves two purposes:

  1. Deliver the client side (JavaScript) webapp to the browser (single page, HTML + CSS + JS).
  2. Server as an HTTP endpoint for the WebSocket connection. If the JS webapp creates a WebSocket connection, it'll contact the HTTP server, which will then upgrade the HTTP connection to the WebSocket protocol.
               HTML         │  ┌─────────────────┐  │
        ┌───────JS──────────┼──│ NIO HTTP Server │  │
        │                   │  └─────────────────┘  │
        │                   │           │           │
        ▼                   │       Upgrades        │
┌──────────────┐            │      Connection       │
│              │            │           │           │
│  WebBrowser  │            │           ▼           │       ┌──────────────┐
│              │  WebSocket │  ┌─────────────────┐  │       │              │
│  JavaScript  │◀────JSON───┼─▶│  NIO WebSocket  │◀─┼─IRC──▶│  IRC Server  │
│    WebApp    │            │  └─────────────────┘  │       │              │
│              │            │       WebServer       │       └──────────────┘
└──────────────┘            └───────────────────────┘

JavaScript Client

The JavaScript web app is embedded into the compiled Swift module (using a Makefile all the resources are bundled together into a single Swift source file). Yet it also works as a standalone web application (you can drag the Client.html into your browser.

The client app is located in Sources/IRCWebClient/WebApp.

Importing the module using Swift Package Manager

An example Package.swift importing the necessary modules:

// swift-tools-version:5.0

import PackageDescription

let package = Package(
    name: "MyOwnIRCServer",
    dependencies: [
        .package(url: "https://github.com/NozeIO/swift-nio-irc-webclient.git",
                 from: "0.7.0")
    targets: [
        .target(name: "MyIRCServer",
                dependencies: [ "IRCServer", "IRCWebClient" ])

Using the Server

let webServer = IRCWebClientServer()

Check the Configuration object for the supported configuration options.

One can configure three connection parameters:

  1. host/port - this is the address the HTTP server is running on
  2. ircHost/port - this is the address of the IRC server
  3. externalHost/port - the address the browser is using to connect to the HTTP server. Often but not necessarily the same like 1.


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  • Swift Tools 5.0.0
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Last updated: Wed Feb 01 2023 18:22:58 GMT-0500 (GMT-05:00)