Function render

test/angular/1.3/angular.js:26100–26284

()

        }

        function render() {
          renderScheduled = false;

          // Temporary location for the option groups before we render them
          var optionGroups = {'':[]},
              optionGroupNames = [''],
              optionGroupName,
              optionGroup,
              option,
              existingParent, existingOptions, existingOption,
              viewValue = ctrl.$viewValue,
              values = valuesFn(scope) || [],
              keys = keyName ? sortedKeys(values) : values,
              key,
              value,
              groupLength, length,
              groupIndex, index,
              labelMap = {},
              selected,
              isSelected = createIsSelectedFn(viewValue),
              anySelected = false,
              lastElement,
              element,
              label,
              optionId;

          trackKeysCache = {};

          // 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;
            }
            value = values[key];

            optionGroupName = callExpression(groupByFn, key, value) || '';
            if (!(optionGroup = optionGroups[optionGroupName])) {
              optionGroup = optionGroups[optionGroupName] = [];
              optionGroupNames.push(optionGroupName);
            }

            selected = isSelected(key, value);
            anySelected = anySelected || selected;

            label = callExpression(displayFn, key, value); // what will be seen by the user

            // doing displayFn(scope, locals) || '' overwrites zero values
            label = isDefined(label) ? label : '';
            optionId = trackFn ? trackFn(scope, locals) : (keyName ? keys[index] : index);
            if (trackFn) {
              trackKeysCache[optionId] = key;
            }

            optionGroup.push({
              // either the index into array or key from object
              id: optionId,