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#!/usr/bin/env rackup -s thin
#
# async_chat.ru
# raggi/thin
#
# Created by James Tucker on 2008-06-19.
# Copyright 2008 James Tucker <raggi@rubyforge.org>.
# Uncomment if appropriate for you..
EM.epoll
# EM.kqueue # bug on OS X in 0.12?
class DeferrableBody
include EventMachine::Deferrable
def initialize
@queue = []
end
def schedule_dequeue
return unless @body_callback
EventMachine::next_tick do
next unless body = @queue.shift
body.each do |chunk|
@body_callback.call(chunk)
end
schedule_dequeue unless @queue.empty?
end
end
def call(body)
@queue << body
schedule_dequeue
end
def each &blk
@body_callback = blk
schedule_dequeue
end
end
class Chat
module UserBody
attr_accessor :username
end
def initialize
@users = {}
end
def render_page
[] << <<-EOPAGE
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html>
<head>
<style>
body {
font-family: sans-serif;
margin: 0;
padding: 0;
margin-top: 4em;
margin-bottom: 1em;
}
#header {
background: silver;
height: 4em;
width: 100%;
position: fixed;
top: 0px;
border-bottom: 1px solid black;
padding-left: 0.5em;
}
#messages {
width: 100%;
height: 100%;
}
.message {
margin-left: 1em;
}
#send_form {
position: fixed;
bottom: 0px;
height: 1em;
width: 100%;
}
#message_box {
background: silver;
width: 100%;
border: 0px;
border-top: 1px solid black;
}
.gray {
color: gray;
}
</style>
<script type="text/javascript" src="http://ra66i.org/tmp/jquery-1.2.6.min.js"></script>
<script type="text/javascript">
XHR = function() {
var request = false;
try { request = new ActiveXObject('Msxml2.XMLHTTP'); } catch(e) {
try { request = new ActiveXObject('Microsoft.XMLHTTP'); } catch(e1) {
try { request = new XMLHttpRequest(); } catch(e2) {
return false;
}
}
}
return request;
}
scroll = function() {
window.scrollBy(0,50);
setTimeout('scroll()',100);
}
focus = function() {
$('#message_box').focus();
}
send_message = function(message_box) {
xhr = XHR();
xhr.open("POST", "/", true);
xhr.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
xhr.setRequestHeader("X_REQUESTED_WITH", "XMLHttpRequest");
xhr.send("message="+escape(message_box.value));
scroll();
message_box.value = '';
focus();
return false;
}
new_message = function(username, message) {
// TODO html escape message
formatted_message = "<div class='message'>" + username + ": " + message + "</div>";
messages_div = $('#messages');
$(formatted_message).appendTo(messages_div);
scroll();
return true;
}
</script>
<title>Async Chat</title>
</head>
<body>
<div id="header">
<h1>Async Chat</h1>
</div>
<div id="messages" onclick="focus();">
<span class="gray">Your first message will become your nickname!</span>
<span>Users: #{@users.map{|k,u|u.username}.join(', ')}</span>
</div>
<form id="send_form" onSubmit="return send_message(this.message)">
<input type="text" id="message_box" name="message"></input>
</form>
<script type="text/javascript">focus();</script>
</body>
</html>
EOPAGE
end
def register_user(user_id, renderer)
body = create_user(user_id)
body.call render_page
body.errback { delete_user user_id }
body.callback { delete_user user_id }
EventMachine::next_tick do
renderer.call [200, {'Content-Type' => 'text/html'}, body]
end
end
def new_message(user_id, message)
return unless @users[user_id]
if @users[user_id].username == :anonymous
username = unique_username(message)
log "User: #{user_id} is #{username}"
@users[user_id].username = message
message = "<span class='gray'>-> #{username} signed on.</span>"
end
username ||= @users[user_id].username
log "User: #{username} sent: #{message}"
@users.each do |id, body|
EventMachine::next_tick { body.call [js_message(username, message)] }
end
end
private
def unique_username(name)
name.concat('_') while @users.any? { |id,u| name == u.username }
name
end
def log(str)
print str, "\n"
end
def add_user(id, body)
@users[id] = body
end
def delete_user(id)
message = "User: #{id} - #{@users[id].username if @users[id]} disconnected."
log message
new_message(id, message)
@users.delete id
end
def js_message(username, message)
%(<script type="text/javascript">new_message("#{username}","#{message}");</script>)
end
def create_user(id)
message = "User: #{id} connected."
log message
new_message(id, message)
body = DeferrableBody.new
body.extend UserBody
body.username = :anonymous
add_user(id, body)
body
end
end
class AsyncChat
AsyncResponse = [-1, {}, []].freeze
AjaxResponse = [200, {}, []].freeze
def initialize
@chat = Chat.new
end
def call(env)
request = Rack::Request.new(env)
# TODO - cookie me, baby
user_id = request.env['REMOTE_ADDR']
if request.xhr?
message = request['message']
@chat.new_message(user_id, Rack::Utils.escape_html(message))
AjaxResponse
else
renderer = request.env['async.callback']
@chat.register_user(user_id, renderer)
AsyncResponse
end
end
end
run AsyncChat.new
|
