Function render

test/angular/1.2/angular.js:21947–22119

()

        function render() {
              // Temporary location for the option groups before we render them
          var optionGroups = {'':[]},
              optionGroupNames = [''],
              optionGroupName,
              optionGroup,
              option,
              existingParent, existingOptions, existingOption,
              modelValue = ctrl.$modelValue,
              values = valuesFn(scope) || [],
              keys = keyName ? sortedKeys(values) : values,
              key,
              groupLength, length,
              groupIndex, index,
              locals = {},
              selected,
              selectedSet = getSelectedSet(),
              lastElement,
              element,
              label;


          // We now build up the list of options we need (we merge later)
          for (index = 0; length = keys.length, index < length; index++) {

            key = index;
            if (keyName) {
              key = keys[index];
              if ( key.charAt(0) === '$' ) continue;
              locals[keyName] = key;
            }

            locals[valueName] = values[key];

            optionGroupName = groupByFn(scope, locals) || '';
            if (!(optionGroup = optionGroups[optionGroupName])) {
              optionGroup = optionGroups[optionGroupName] = [];
              optionGroupNames.push(optionGroupName);
            }
            if (multiple) {
              selected = isDefined(
                selectedSet.remove(trackFn ? trackFn(scope, locals) : valueFn(scope, locals))
              );
            } else {
              if (trackFn) {
                var modelCast = {};
                modelCast[valueName] = modelValue;
                selected = trackFn(scope, modelCast) === trackFn(scope, locals);
              } else {
                selected = modelValue === valueFn(scope, locals);
              }
              selectedSet = selectedSet || selected; // see if at least one item is selected
            }
            label = displayFn(scope, locals); // what will be seen by the user

            // doing displayFn(scope, locals) || '' overwrites zero values
            label = isDefined(label) ? label : '';
            optionGroup.push({