angularjs_validate_required
HTML
<body ng-app="">
<form name="myForm">
<input name="myInput" ng-model="myInput" required>
</form>
<p>The input's valid state is:</p>
<h1>{{myForm.myInput.$valid}}</h1>
</body>CSS
<style>
input.ng-invalid {
background-color: #FFF;
}
input.ng-valid {
background-color: lightgreen;
}
</style>