examples/server_sent_events.rb in reel-0.4.0 vs examples/server_sent_events.rb in reel-0.5.0.pre

@@ -1,69 +1,73 @@
 #!/usr/bin/env ruby
+# See: http://www.w3.org/TR/eventsource/
 # Run with: bundle exec examples/server_sent_events.rb
 # Test with: curl -vNH 'Accept: text/event-stream' -H 'Last-Event-ID: 1' -H 'Cache-Control: no-cache' http://localhost:63310
 
 require 'bundler/setup'
 require 'time'
 require 'reel'
 
-class ServerSentEvents < Reel::Server
+
+class ServerSentEvents < Reel::Server::HTTP
   include Celluloid::Logger
   
   def initialize(ip = '127.0.0.1', port = 63310)
     @connections = []
     @history = []
-    @lastMessageId = 0
+    @lastEventId = 0
     async.ping
-    async.ring
+    async.ring #not needed for Production, only to have some events here.
     super(ip, port, &method(:on_connection))
   end
 
+  #broadcasts events to all clients
   def broadcast(event, data)
     #only keep the last 5000 Events
     if @history.size >= 6000
       @history.slice!(0, @history.size - 1000)
     end
-    @lastMessageId += 1
-    @history << {id: @lastMessageId, event: event, data: data}
+    @lastEventId += 1
+    @history << {id: @lastEventId, event: event, data: data}
     info "Sending Event: #{event} Data: #{data} to #{@connections.count} Clients"
     @connections.each do |socket|
-      async.send_sse(socket, data, event, @lastMessageId)
+      async.send_sse(socket, data, event, @lastEventId)
     end
     true
   end
 
   private
-  #event and id are optional
+  #event and id are optional, Eventsource only needs data
   def send_sse(socket, data, event = nil, id = nil)
     begin
       socket.id id if id
       socket.event event if event
       socket.data data
-    rescue IOError, Errno::ECONNRESET, Errno::EPIPE
-      @connections.delete(socket)
+    rescue Reel::SocketError, NoMethodError
+      @connections.delete(socket) if @connections.include?(socket)
     end
   end
 
+  #Lines that start with a Colon are Comments and will be ignored
   def send_ping
     @connections.each do |socket|
       begin
-        #Lines that start with a Colon are Comments and will be ignored
         socket << ":\n"
-      rescue IOError, Errno::ECONNRESET, Errno::EPIPE
+      rescue Reel::SocketError
         @connections.delete(socket)
       end
     end
   end
 
+  #apache 2.2 closes connections after five seconds when nothing is send, see this as a poor mans Keep-Alive
   def ping
-    #apache 2.2 closes connections after five seconds when nothing is send
     every(5) do
       send_ping
     end
   end
 
+  #only used to have some events here, not needed for Production.
   def ring
     every(2) do
       broadcast(:time, Time.now.httpdate)
     end
   end
@@ -75,23 +79,23 @@
       if key && value
         key, value = CGI.unescape(key), CGI.unescape(value)
         query[key] = value
       end
     end
-    body = Reel::EventStream.new do |socket|
+    #see https://github.com/celluloid/reel/blob/master/lib/reel/stream.rb#L35
+    eventStream = Reel::EventStream.new do |socket|
       @connections << socket
       socket.retry 5000
-      #after a Connection reset resend newer Messages to the Client
+      #after a Connection reset resend newer Messages to the Client, query['lastEventId'] is needed for https://github.com/Yaffle/EventSource
       if @history.count > 0 && id = (request.headers['Last-Event-ID'] || query['lastEventId'])
         begin
-          id = Integer(id)
-          if history = @history.select {|h| h[:id] >= id}.map {|a| "id: %d\nevent: %s\ndata: %s" % [a[:id], a[:event], a[:data]]}.join("\n\n")
+          if history = @history.select {|h| h[:id] >= Integer(id)}.map {|a| "id: %d\nevent: %s\ndata: %s" % [a[:id], a[:event], a[:data]]}.join("\n\n")
             socket << "%s\n\n" % [history]
           else
             socket << "id\n\n"
           end
-        rescue ArgumentError, IOError, Errno::ECONNRESET, Errno::EPIPE
+        rescue ArgumentError, Reel::SocketError
           @connections.delete(socket)
           request.close
         end
       else
         socket << "id\n\n"
@@ -100,10 +104,10 @@
     #X-Accel-Buffering is nginx(?) specific. Setting this to "no" will allow unbuffered responses suitable for Comet and HTTP streaming applications
     request.respond Reel::StreamResponse.new(:ok, {
       'Content-Type' => 'text/event-stream; charset=utf-8',
       'Cache-Control' => 'no-cache',
       'X-Accel-Buffering' => 'no',
-      'Access-Control-Allow-Origin' => '*'}, body)
+      'Access-Control-Allow-Origin' => '*'}, eventStream)
   end
 
   def on_connection(connection)
     connection.each_request do |request|
       handle_request(request)