Angularjs validation for ui-select multiple

Question

THE SITUATION:

I have an angular app that send emails. There is a form with three fields: Address - Subject - Text.

For the address field I am using angular ui-select.

Everything is working fine, except the validation on the address field (on subject and text validation is working properly).

EDIT:

This bug has been fixed from version 0.16.1. as pointed out by @yishaiz.

So this question and its relative solution regard ui-select versions < 0.16.1.

THE CODE:

HTML:

 <form name="emailForm" ng-submit="submitForm(emailForm.$valid)"> 

    <div class="row form-group">

        <label class="col-sm-2 control-label">To: </label>

        <div class="col-sm-10">

            <ui-select multiple ng-model="database_people.selectedPeople" theme="select2" ng-disabled="disabled" style="width:100%">

              <ui-select-match placeholder="Select person...">{{$item.name}} &lt; {{$item.value}} &gt;</ui-select-match>

              <ui-select-choices repeat="person2 in list_people | filter: {name: $select.search.name, value: $select.search.value, db_data_type_id: 5}">

                  <div ng-bind-html="person2.name | highlight: $select.search"></div>

                    <small>

                        email: <span ng-bind-html="''+person2.value | highlight: $select.search"></span>

                    </small>

              </ui-select-choices>

            </ui-select>

        </div>

    </div>

    <div class="col-sm-8">

         <button type="submit" class="btn btn-primary">Send</button>

    </div>

</form>

ANGULARJS:

$scope.submitForm = function(isValid) 
 {
    if (isValid) {
        alert('valid');
    }
    else {
        alert('not valid')
    }
};

PLUNKER:

http://plnkr.co/edit/MYW7SM9c9anH6RTomfRG?p=preview

As you can see the ui-select is required but the form is parse as valid.

QUESTION(s):

How can i make the ui-select multiple required?

Answer 1

Since angular#1.3, the angular way to do so is to create a custom (validation) directive.

Directive:

angular.module('myApp').directive('requireMultiple', function () {
    return {
        require: 'ngModel',
        link: function postLink(scope, element, attrs, ngModel) {
            ngModel.$validators.required = function (value) {
                return angular.isArray(value) && value.length > 0;
            };
        }
    };
});

Code becomes:

<ui-select name="test"
           multiple 
           require-multiple  
           ng-model="database_people.selectedPeople" ...>
  <ui-select-match placeholder="Select person...">...
  </ui-select-match>
  <ui-select-choices ...>
        ...
  </ui-select-choices>
</ui-select>

Adapted from this solution

PS: you can also use ng-messages to properly display an error if validation fail. Example:

<div ng-messages="emailForm.test.$error" >
  <p ng-message="required">Custom message here</p>
</div>