Function setupAsOptions

test/angular/1.2/angular.js:21809–22120

(scope, selectElement, ctrl)

      }

      function setupAsOptions(scope, selectElement, ctrl) {
        var match;

        if (!(match = optionsExp.match(NG_OPTIONS_REGEXP))) {
          throw ngOptionsMinErr('iexp',
            "Expected expression in form of " +
            "'_select_ (as _label_)? for (_key_,)?_value_ in _collection_'" +
            " but got '{0}'. Element: {1}",
            optionsExp, startingTag(selectElement));
        }

        var displayFn = $parse(match[2] || match[1]),
            valueName = match[4] || match[6],
            keyName = match[5],
            groupByFn = $parse(match[3] || ''),
            valueFn = $parse(match[2] ? match[1] : valueName),
            valuesFn = $parse(match[7]),
            track = match[8],
            trackFn = track ? $parse(match[8]) : null,
            // This is an array of array of existing option groups in DOM.
            // 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:''}]];

        if (nullOption) {
          // compile the element since there might be bindings in it
          $compile(nullOption)(scope);

          // remove the class, which is added automatically because we recompile the element and it
          // becomes the compilation root
          nullOption.removeClass('ng-scope');

          // we need to remove it before calling selectElement.empty() because otherwise IE will
          // remove the label from the element. wtf?
          nullOption.remove();
        }

        // clear contents, we'll add what's needed based on the model
        selectElement.empty();

        selectElement.on('change', function() {
          scope.$apply(function() {
            var optionGroup,
                collection = valuesFn(scope) || [],
                locals = {},
                key, value, optionElement, index, groupIndex, length, groupLength, trackIndex;

            if (multiple) {
              value = [];
              for (groupIndex = 0, groupLength = optionGroupsCache.length;
                   groupIndex < groupLength;
                   groupIndex++) {
                // list of options for that group. (first item has the parent)
                optionGroup = optionGroupsCache[groupIndex];

                for(index = 1, length = optionGroup.length; index < length; index++) {
                  if ((optionElement = optionGroup[index].element)[0].selected) {