WIP: simplify getOptionFromViewValue

Author: petebacondarwin

Diff for: src/ng/directive/ngOptions.js

@@ -248,15 +248,17 @@ var ngOptionsDirective = ['$compile', '$parse', function($compile, $parse) {
     var getGroupName = function(value, key) { return callExpression(groupByFn, value, key) || ''; };
     var getValues = function() { return valuesFn(scope) || []; };
     var getDisplayLabel = function(value, key) { return callExpression(displayFn, value, key); };
-    var getTrackByValue = function(value, key) {
-      return '' + callExpression(trackByFn, value, key);
-    };
     var getViewValue = function(value, key) {
           return (key === '?') ? undefined :
                   (key === '') ? null :
                    callExpression(viewValueFn, value, key);
         };
 
+    // Get the value that represents the object in the options collection
+    var getTrackByValue = trackByFn ? function(value, key) {
+      return '' + callExpression(trackByFn, value, key);
+    } : function(value, key) { return hashKey(value); };
+
     // Get the value that is assigned to and compared to the value of the options
     var getSelectValue = trackByFn ? getTrackByValue : function(value, key) {
       return hashKey(getViewValue(value, key));
@@ -304,11 +306,7 @@ var ngOptionsDirective = ['$compile', '$parse', function($compile, $parse) {
           items: optionItems,
           selectValueMap: selectValueMap,
           getOptionFromViewValue: function(value) {
-            if (!!trackBy) {
-              return selectValueMap.get(getTrackByValue(value));
-            } else {
-              return selectValueMap.get(hashKey(value));
-            }
+            return selectValueMap.get(getTrackByValue(value));
           }
         };
       }