var app = angular.module('ngApp', []);

app.controller('ngCtrl', function($scope) {
});
<!DOCTYPE html>
<html ng-app="ngApp">

<head>
    <meta charset="utf-8" />
    <title>AngularJS Required.</title>
    <link data-require="bootstrap-css@3.3.6" data-semver="3.3.6" rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/css/bootstrap.css" />
    <link rel="stylesheet" href="style.css" />
    <script data-require="angular.js@1.4.x" src="https://code.angularjs.org/1.4.8/angular.js" data-semver="1.4.8"></script>
    <script src="app.js"></script>
</head>

<body ng-controller="ngCtrl">
    <h2>AngularJS 필수입력 체크</h2>
    <form name="form" novalidate>
        <label>
            User name:
            <input type="text" name="name" ng-model="name" ng-required="true">
        </label>
        <div role="alert">
            <span class="error" ng-show="form.name.$dirty && form.name.$error.required">
               Required!
            </span>
        </div>
    </form>
</body>

</html>
/* Put your css in here */