module Lattice

Overview

A lightweight, standalone WebSocket framework for Crystal, derived from Amber's WebSocket implementation. Lattice provides a clean, efficient way to handle real-time communication without the overhead of session management or complex adapters.

Defining a Socket

struct UserSocket < Lattice::ClientSocket
  channel "user_room:*", UserChannel

  def on_connect
    # Add authentication logic here
    true
  end
end

Creating a Channel

class ChatChannel < Lattice::Channel
  def handle_joined(client_socket)
    # Handle user joining chat
  end

  def handle_message(client_socket, message)
    # Process and broadcast message
    rebroadcast!(message)
  end

  def handle_leave(client_socket)
    # Clean up when user leaves
  end
end

Setting Up the Server

require "lattice"

# Initialize WebSocket handler
ws_handler = Lattice::Handler.new("/ws", "UserSocket") do |socket, context|
  UserSocket.new(socket, context)
end

# Add to your HTTP server
server = HTTP::Server.new([
  HTTP::LogHandler.new,
  ws_handler,
])

server.listen(3000)

Custom Application Context

The ClientSocket can be extended to include custom application context:

struct ExtendedUserSocket < Lattice::ClientSocket
  channel "user_room:*", ClientServiceChannel
  property application_context : ApplicationContext

  def initialize(@socket : HTTP::WebSocket, @context : HTTP::Server::Context, @application_context : ApplicationContext)
    super(@socket, @context)
  end

  def on_connect
    @app.auth_service.valid_token?(context.request.headers["Authorization"]?)
  end
end

# Initialize with context
application_context = ApplicationContext.new
ws_handler = Lattice::Handler.new("/ws", "ExtendedUserSocket") do |socket, context|
  ExtendedUserSocket.new(socket, context, application_context).as(Lattice::ClientSocket)
end

Extended Modules

• Lattice

Defined in:

lattice.cr
lattice/channel.cr
lattice/client_socket.cr
lattice/client_sockets.cr
lattice/handler.cr
lattice/subscription_manager.cr

Constant Summary

Log = ::Log.for(self)

VERSION = "0.1.0"

Class Method Summary

• .topic_path(topic)

  Helper method to get the path of a topic

Class Method Detail