Fix issue #8: Add logging of events that flow through event bus

CHANGELOG.md

@@ -1,6 +1,9 @@
 Changelog
 ================
 
+## Version 0.2.3 (2013-09-16) ##
+* Fix issue #8: Add logging of events that flow through event bus
+
 ## Version 0.2.2 (2013-09-16) ##
 * Change default of SimpleEventBus to sync (same as factory in EventBus)
 

example/event_bus_example.dart

@@ -2,13 +2,19 @@ import 'dart:html';
 
 import 'dart:async';
 import 'events.dart' as events;
+import 'package:logging_handlers/logging_handlers_shared.dart';
+import 'package:logging/logging.dart';
 
 int counterA = 1;
 int counterB = 1;
 
 void main() {
+  // Init logging.
+  Logger.root.onRecord.listen(new PrintHandler().call);
+  Logger.root.level = Level.FINEST;
+
   // Initialize the global event bus.
-  events.init(new events.EventBus());
+  events.init(new events.LoggingEventBus());
 
   // Initialize the listener boxes.
   Listener listener1 = new Listener(query('#listener-1'));

example/events.dart

@@ -16,5 +16,5 @@ void init(EventBus eventBus) {
   _eventBus = eventBus;
 }
 
-final EventType<String> textUpdateA = new EventType<String>();
-final EventType<String> textUpdateB = new EventType<String>();
+final EventType<String> textUpdateA = new EventType<String>('textUpdateA');
+final EventType<String> textUpdateB = new EventType<String>('textUpdateB');

lib/event_bus.dart

@@ -1,8 +1,10 @@
 library event_bus;
 
+import 'package:logging/logging.dart';
 import 'dart:async';
 
 part 'src/simple_event_bus.dart';
+part 'src/logging_event_bus.dart';
 
 /**
  * Dispatches events to listeners using the Dart [Stream] API. The [EventBus] 
@@ -58,6 +60,13 @@ abstract class EventBus {
  */
 class EventType<T> {
 
+  String name;
+
+  /**
+   * Constructor with an optional [name] for logging purposes. 
+   */
+  EventType([this.name]);
+
   /**
    * Returns true if the provided data is of type [T]. 
    * 

lib/src/logging_event_bus.dart

@@ -0,0 +1,14 @@
+part of event_bus;
+
+final _logger = new Logger("event_bus");
+
+/**
+ * A [SimpleEventBus] that adds logging. 
+ */
+class LoggingEventBus extends SimpleEventBus {
+
+  void fire(EventType/*<T>*/ eventType, /*<T>*/ data) {
+    super.fire(eventType, data);
+    _logger.finest('event fired:  ${eventType.name}');
+  }
+}

pubspec.yaml

@@ -1,9 +1,12 @@
 name: event_bus
-version: 0.2.2
+version: 0.2.3
 author: Marco Jakob <majakob@gmx.ch>
 description: A simple Event Bus using Dart Streams for decoupling applications
 homepage: https://github.com/marcojakob/dart-event-bus
 documentation: http://edu.makery.ch/projects/dart-event-bus
+dependencies:
+  logging: any
 dev_dependencies:
   browser: any
+  logging_handlers: any
   unittest: any