Function ngOptionsPostLink

lib/test/angular/1.5.0/angular.js:27461–27793

(scope, selectElement, attr, ctrls)

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

      var options;
      var ngOptions = parseOptionsExpression(attr.ngOptions, selectElement, scope);


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

      var removeEmptyOption = function() {
        if (!providedEmptyOption) {
          emptyOption.remove();
        }
      };


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

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

      // Update the controller methods for multiple selectable options
      if (!multiple) {

        selectCtrl.writeValue = function writeNgOptionsValue(value) {
          var option = options.getOptionFromViewValue(value);