Function ngOptionsPostLink

test/angular/1.5/angular.js:29520–29839

(scope, selectElement, attr, ctrls)

      optGroupTemplate = window.document.createElement('optgroup');

    function ngOptionsPostLink(scope, selectElement, attr, ctrls) {

      var selectCtrl = ctrls[0];
      var ngModelCtrl = ctrls[1];
      var multiple = attr.multiple;

      // The emptyOption allows the application developer to provide their own custom "empty"
      // option when the viewValue does not match any of the option values.
      var emptyOption;
      for (var i = 0, children = selectElement.children(), ii = children.length; i < ii; i++) {
        if (children[i].value === '') {
          emptyOption = children.eq(i);
          break;
        }
      }

      var providedEmptyOption = !!emptyOption;
      var emptyOptionRendered = false;

      var unknownOption = jqLite(optionTemplate.cloneNode(false));
      unknownOption.val('?');

      var options;
      var ngOptions = parseOptionsExpression(attr.ngOptions, selectElement, scope);
      // This stores the newly created options before they are appended to the select.
      // Since the contents are removed from the fragment when it is appended,
      // we only need to create it once.
      var listFragment = $document[0].createDocumentFragment();

      var renderEmptyOption = function() {
        if (!providedEmptyOption) {
          selectElement.prepend(emptyOption);
        }
        selectElement.val('');
        if (emptyOptionRendered) {
          emptyOption.prop('selected', true); // needed for IE
          emptyOption.attr('selected', true);
        }
      };

      var removeEmptyOption = function() {
        if (!providedEmptyOption) {
          emptyOption.remove();
        } else if (emptyOptionRendered) {
          emptyOption.removeAttr('selected');
        }
      };

      var renderUnknownOption = function() {
        selectElement.prepend(unknownOption);
        selectElement.val('?');
        unknownOption.prop('selected', true); // needed for IE
        unknownOption.attr('selected', true);
      };

      var removeUnknownOption = function() {
        unknownOption.remove();
      };