fix(NodeAttrs): lazy init of observer listeners

vicb · vicb · commit 144eb4c76598 · 2014-03-17T09:54:50.000+01:00
diff --git a/lib/core_dom/directive.dart b/lib/core_dom/directive.dart
@@ -16,7 +16,7 @@ class NodeAttrs {
 
   Map<String, List<AttributeChanged>> _observers;
 
-  Map<String, List<ObserverChanged>> _observerListeners = {};
+  Map<String, List<ObserverChanged>> _observerListeners;
 
   NodeAttrs(this.element);
 
@@ -45,7 +45,8 @@ class NodeAttrs {
 
     notifyFn(this[attributeName]);
 
-    if (_observerListeners.containsKey(attributeName)) {
+    if (_observerListeners != null &&
+        _observerListeners.containsKey(attributeName)) {
       _observerListeners[attributeName].forEach((cb) => cb(true));
     }
   }

Original file line number	Diff line number	Diff line change
`@@ -16,7 +16,7 @@ class NodeAttrs {`
`16`	`16`
`17`	`17`	`Map<String, List<AttributeChanged>> _observers;`
`18`	`18`
`19`		`- Map<String, List<ObserverChanged>> _observerListeners = {};`
	`19`	`+ Map<String, List<ObserverChanged>> _observerListeners;`
`20`	`20`
`21`	`21`	`NodeAttrs(this.element);`
`22`	`22`
`@@ -45,7 +45,8 @@ class NodeAttrs {`
`45`	`45`
`46`	`46`	`notifyFn(this[attributeName]);`
`47`	`47`
`48`		`- if (_observerListeners.containsKey(attributeName)) {`
	`48`	`+ if (_observerListeners != null &&`
	`49`	`+ _observerListeners.containsKey(attributeName)) {`
`49`	`50`	`_observerListeners[attributeName].forEach((cb) => cb(true));`
`50`	`51`	`}`
`51`	`52`	`}`