<!DOCTYPE html>
<html>
<script src="http://ajax.googleapis.com/ajax/libs/angularjs/1.4.8/angular.min.js"></script>
<body>
<script>
var app = angular.module("myShoppingList", []);
app.controller("myCtrl", function($scope) {
$scope.products = ["Milk", "Bread", "Cheese"];
$scope.addItem = function () {
$scope.errortext = "";
if (!$scope.addMe) {return;}
if ($scope.products.indexOf($scope.addMe) == -1) {
$scope.products.push($scope.addMe);
} else {
$scope.errortext = "The item is already in your shopping list.";
}
}
$scope.removeItem = function (x) {
$scope.errortext = "";
$scope.products.splice(x, 1);
}
});
</script>
<div ng-app="myShoppingList" ng-controller="myCtrl">
<ul>
<li ng-repeat="x in products">{{x}}<span ng-click="removeItem($index)">×</span></li>
</ul>
<input ng-model="addMe">
<button ng-click="addItem()">Add</button>
<p>{{errortext}}</p>
</div>
<p>Try to add the same item twice, and you will get an error message.</p>
</body>
</html>