From d2974cfca3bcf410fc72b3e7b906aceb01fc2b21 Mon Sep 17 00:00:00 2001
From: Sam Stephenson <sam@37signals.com>
Date: Sat, 11 Aug 2007 19:07:21 +0000
Subject: [PATCH] prototype: Make sure Element#stopObserving is always
 chainable.

---
 CHANGELOG            |  2 ++
 src/event.js         | 12 +++++++-----
 test/unit/event.html | 11 +++++++++++
 3 files changed, 20 insertions(+), 5 deletions(-)

diff --git a/CHANGELOG b/CHANGELOG
index 36d2b75..2d0ef6b 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,5 +1,7 @@
 *SVN*
 
+* Make sure Element#stopObserving is always chainable.  [sam]
+
 * Event.fire/Element#fire now returns the newly-fired event instead of the event's target element.  [sam]
 
 * Restrict Event.DOMEvents to include only events that can be supported in all browsers.  [sam]
diff --git a/src/event.js b/src/event.js
index 21ddd03..6a6d68b 100644
--- a/src/event.js
+++ b/src/event.js
@@ -186,18 +186,20 @@ Object.extend(Event, (function() {
       var id = getEventID(element), name = getDOMEventName(eventName);
       
       if (!handler && eventName) {
-        return getWrappersForEventName(id, eventName).each(function(wrapper) {
+        getWrappersForEventName(id, eventName).each(function(wrapper) {
           element.stopObserving(eventName, wrapper.handler);
-        }) && false;
+        });
+        return element;
         
       } else if (!eventName) {
-        return Object.keys(getCacheForID(id)).each(function(eventName) {
+        Object.keys(getCacheForID(id)).each(function(eventName) {
           element.stopObserving(eventName);
-        }) && false;
+        });
+        return element;
       }
       
       var wrapper = findWrapper(id, eventName, handler);
-      if (!wrapper) return false;
+      if (!wrapper) return element;
       
       if (element.removeEventListener) {
         element.removeEventListener(name, wrapper, false);
diff --git a/test/unit/event.html b/test/unit/event.html
index a8aba77..6c2f365 100644
--- a/test/unit/event.html
+++ b/test/unit/event.html
@@ -183,6 +183,17 @@
       assertEqual(0, Event.cache[eventID].somethingHappened.length);
     }},
     
+    testStopObservingIsChainable: function() { with(this) {
+      var span = $("span"), observer = function() { };
+      span.observe("somethingHappened", observer);
+      assertEqual(span, span.stopObserving("somethingHappened", observer));
+      span.observe("somethingHappened", observer);
+      assertEqual(span, span.stopObserving("somethingHappened"));
+      span.observe("somethingHappened", observer);
+      assertEqual(span, span.stopObserving());
+      assertEqual(span, span.stopObserving()); // assert it again, after there are no observers
+    }},
+    
     testDocumentContentLoadedEventFiresBeforeWindowLoad: function() { with(this) {
       assert(eventResults.contentLoaded, "contentLoaded");
       assert(eventResults.contentLoaded.endOfDocument, "contentLoaded.endOfDocument");