Как предотвратить игнорирование формы пользователя в angularjs angular-ui-bootstrap uib-typeahead

Я использую AngularJS v1.6.6 и версию angular-ui-bootstrap: 2.5.0 для создания поля автозаполнения.

Все работает правильно, но мне нужен способ убедиться, что пользователь действительно выбирает вариант из списка предложений.

Вот мой код:

HTML:

<div class='container-fluid typeahead-demo' ng-controller="TypeaheadCtrl">
<h4>How to prevent user from typing the whole word ignoring suggestions?</h4>
<div>Model: 
<pre>{{selected | json}}</pre>
</div>
<form role="form" name="chooseStateForm" autocomplete="off" novalidate>
    <div class="form-group required">
        <div>
            <label for="state" class="control-label col-sm-3">Choose a State:</label>
                <input type="text" 
                        class="form-control" 
                        required 
                        placeholder="Try typing the whole name of the state ignoring suggestion" 
                        name="state" 
                        ng-model="selected" 
                        uib-typeahead="option as option.name for option in states | filter:{name: $viewValue}" 
                        typeahead-min-length="1" 
                        typeahead-no-results="noresults" 
                        typeahead-show-hint="true" 
                        >
        </div>
        <div ng-if="noresults">
        <p>No match found!</p>
        </div>
    </div>
</form>
<br><br><br><br>
<div>
    <button class="btn btn-primary" type="button" ng-click="$ctrl.ok()" ng-disabled="chooseStateForm.$invalid">OK</button>
    <button class="btn btn-primary" type="button" ng-click="$ctrl.cancel()">Cancel</button>
</div>

JS:

angular.module('app', ['ui.bootstrap']);
angular.module('app').controller('TypeaheadCtrl', function($scope) {

$scope.selected = undefined;
$scope.states = [
{id: 1, name: 'Alabama'},  
{id: 2, name: 'California'}, 
{id: 3, name: 'Delaware'}, 
{id: 4, name: 'Florida'}, 
{id: 5, name: 'Georgia'}, 
{id: 6, name: 'Hawaii'}, 
{id: 7, name: 'Idaho'},  
{id: 8, name: 'Kansas'}, 
{id: 9, name: 'Louisiana'}, 
{id: 10, name: 'Maine'}, 
{id: 11, name: 'Nebraska'}, 
{id: 12, name: 'Ohio'}, 
{id: 13, name: 'Pennsylvania'}, 
{id: 14, name: 'Rhode Island'}, 
{id: 15, name: 'South Carolina'}, 
{id: 16, name: 'Tennessee'},
{id: 17, name: 'Utah'}, 
{id: 18, name: 'Vermont'}, 
{id: 19, name: 'Washington'}
];
});

Посмотрите этот jsfiddle, и вы поймете, что я имею в виду: http://jsfiddle.net/elenat82/yhpbdvva/ 20/

Вот ссылка на обновленный jsfiddle: http://jsfiddle.net/elenat82/fL5fw1up/2/

И вот обновленный код:

HTML:

<div class='container-fluid typeahead-demo' ng-controller="TypeaheadCtrl">
<h4>How to prevent user from typing the whole word ignoring suggestions?</h4>
<div>Model: 
<pre>{{selected | json}}</pre>
<div>Errors: 
<pre>{{chooseStateForm.state.$error | json}}</pre>
</div>
<form role="form" name="chooseStateForm" autocomplete="off" novalidate>
    <div class="form-group required">
        <div>
            <label for="state" class="control-label col-sm-3">Choose a State:</label>
                <input type="text" 
                        class="form-control" 
                        required 
                        placeholder="Try typing the whole name of the state ignoring suggestion" 
                        name="state" 
                        ng-model="selected" 
                        uib-typeahead="option as option.name for option in states | filter:{name: $viewValue}" 
                        typeahead-min-length="1" 
                        typeahead-no-results="noresults" 
                        typeahead-show-hint="true" 
                        object
                        >
        </div>
        <div ng-if="noresults">
        <p>No match found!</p>
        </div>
    </div>
</form>
<br><br><br><br>
<div>
    <button class="btn btn-primary" type="button" ng-click="$ctrl.ok()" ng-disabled="chooseStateForm.$invalid">OK</button>
    <button class="btn btn-primary" type="button" ng-click="$ctrl.cancel()">Cancel</button>
</div>

JS:

angular.module('app', ['ui.bootstrap']);
angular.module('app').controller('TypeaheadCtrl', function($scope) {

$scope.selected = undefined;
$scope.states = [
{id: 1, name: 'Alabama'},  
{id: 2, name: 'California'}, 
{id: 3, name: 'Delaware'}, 
{id: 4, name: 'Florida'}, 
{id: 5, name: 'Georgia'}, 
{id: 6, name: 'Hawaii'}, 
{id: 7, name: 'Idaho'},  
{id: 8, name: 'Kansas'}, 
{id: 9, name: 'Louisiana'}, 
{id: 10, name: 'Maine'}, 
{id: 11, name: 'Nebraska'}, 
{id: 12, name: 'Ohio'}, 
{id: 13, name: 'Pennsylvania'}, 
{id: 14, name: 'Rhode Island'}, 
{id: 15, name: 'South Carolina'}, 
{id: 16, name: 'Tennessee'},
{id: 17, name: 'Utah'}, 
{id: 18, name: 'Vermont'}, 
{id: 19, name: 'Washington'}
];
});


angular.module('app').directive('object', [function() {
return {
    restrict: 'A',
    scope: {},
    require: 'ngModel',
    link: function (scope, element, attrs, ngModel) {

        ngModel.$validators.object = function(modelValue,viewValue){
            if (angular.isObject(modelValue)) {
                return true;
            }
            else {
                return false;
            }
          };
    }
};

}
]);