WIP: use one locals object

Author: jeffbcross

src/ng/directive/select.js

@@ -345,7 +345,9 @@ var selectDirective = ['$compile', '$parse', function($compile,   $parse) {
             // We try to reuse these if possible
             // - optionGroupsCache[0] is the options with no option group
             // - optionGroupsCache[?][0] is the parent: either the SELECT or OPTGROUP element
-            optionGroupsCache = [[{element: selectElement, label:''}]];
+            optionGroupsCache = [[{element: selectElement, label:''}]],
+            //re-usable object to represent option's locals
+            locals = {};
 
         if (nullOption) {
           // compile the element since there might be bindings in it
@@ -367,7 +369,6 @@ var selectDirective = ['$compile', '$parse', function($compile,   $parse) {
           scope.$apply(function() {
             var optionGroup,
                 collection = valuesFn(scope) || [],
-                locals = {},
                 key, value, optionElement, index, groupIndex, length, groupLength, trackIndex;
             var selectedKeys = selectElement.val();
             var viewValue;
@@ -388,8 +389,7 @@ var selectDirective = ['$compile', '$parse', function($compile,   $parse) {
 
         scope.$watchCollection(valuesFn, scheduleRendering);
         scope.$watchCollection(function () {
-          var locals = {},
-              values = valuesFn(scope);
+          var values = valuesFn(scope);
           if (values) {
             var toDisplay = new Array(values.length);
             for (var i = 0, ii = values.length; i < ii; i++) {
@@ -411,7 +411,6 @@ var selectDirective = ['$compile', '$parse', function($compile,   $parse) {
             var viewValue = ctrl.$viewValue;
             if (trackFn && isArray(viewValue) && !selectAs) {
               selectedSet = new HashMap([]);
-              var locals = {};
               for (var trackIndex = 0; trackIndex < viewValue.length; trackIndex++) {
                 locals[valueName] = viewValue[trackIndex];
                 selectedSet.put(trackFn(scope, locals), viewValue[trackIndex]);
@@ -436,8 +435,6 @@ var selectDirective = ['$compile', '$parse', function($compile,   $parse) {
 
         // TODO: Use this method everywhere
         function callExpression(exprFn, key, collection) {
-          // TODO: keep this as a central object, no need to recreate this
-          var locals = {};
           locals[valueName] = collection[key];
           if (keyName) locals[keyName] = key;
           return exprFn(scope, locals);
@@ -489,7 +486,6 @@ var selectDirective = ['$compile', '$parse', function($compile,   $parse) {
               key,
               groupLength, length,
               groupIndex, index,
-              locals = {},
               selected,
               selectedSet = getSelectedSet(),
               lastElement,
@@ -502,10 +498,10 @@ var selectDirective = ['$compile', '$parse', function($compile,   $parse) {
             if (keyName) {
               key = keys[index];
               if ( key.charAt(0) === '$' ) continue;
-              locals[keyName] = key;
             }
 
-            locals[valueName] = values[key];
+            //Called without assigning value to reset properties of locals object
+            var optionValue = callExpression(noop, key, values);
 
             optionGroupName = groupByFn(scope, locals) || '';
             if (!(optionGroup = optionGroups[optionGroupName])) {