hi I have problem with custom validation in js plugin:

my html:

<div id="u7dtgSliderEvent" ng-controller="u7dtgSliderEvent.editorController"> <input type="hidden" ng-model="validationTest" val-property-validator="validateMandatory" />

my js:

angular.module("umbraco") .controller("u7dtgSliderEvent.editorController", function ($scope, $timeout) {

        $scope.validationTest = null;

        $scope.validateMandatory = function () {
            return {
                isValid: false,
                errorMsg: "Value cannot be empty",
                errorKey: "required"
            };
        }
    });

validateMandatory function is executed ones on plugin load, return false, but nothing happend on saving data. What i make wrong?

i took this example from https://github.com/umbraco/Umbraco-CMS/tree/9290f61f9485c5bef0aa9a95e05e8acefa9ce221/src/Umbraco.Web.UI.Client/src/views/propertyeditors/tags

but it doesnt work.

Can somebody help my?