JSFiddle - React, Tailwind, and code Playground

HTML

<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.5/css/bootstrap.min.css">
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.5/js/bootstrap.min.js"></script>
<div ng-app="validationApp" ng-controller="ExampleController">
    <div class="container">
        <form class="form-horizontal" name="signup_form" novalidate="">
            <!-- HTML Type text -->
            <div class="form-group" ng-class="{ 'has-error' : signup_form.textInput[0].$dirty && signup_form.textInput[0].$invalid, 'has-success' : signup_form.textInput[0].$valid  }">
                <label for="textInput" class="col-sm-2 control-label">Text</label>
                <div class="col-sm-5">
                    <input type="text" class="form-control" name="textInput[0]" data-ng-model="textInput[0]" data-ng-minlength=3 data-ng-maxlength=10 data-ng-pattern='/^[a-zA-Z ]*$/' required="1" id="textInput[0]" placeholder="Text">
                    <div class="error-container" ng-show="signup_form.textInput[0].$dirty && signup_form.textInput[0].$invalid"> <small class="help-block" ng-show="signup_form.textInput[0].$error.required">Please input a username</small>
 <small class="help-block" ng-show="signup_form.textInput[0].$error.minlength">at least 3 characters</small>
 <small class="help-block" ng-show="signup_form.textInput[0].$error.maxlength">Your username cannot be longer than 10 characters</small>
 <small class="help-block" ng-show="signup_form.textInput[0].$error.pattern">Invalid Pattern</small>

                    </div>
                </div>
            </div>
            <div class="form-group">
                <div class="col-sm-offset-2 col-sm-10">
                    <button type="submit" ng-disabled="signup_form.$invalid" class="btn btn-default">Sign in</button>
                </div>
            </div>
        </form>
    </div>
</div>

JavaScript

// create angular app
 var validationApp = angular.module('validationApp', []);

 // create angular controller
 validationApp.controller('ExampleController', function ($scope) {

     // function to submit the form after all validation has occurred      
     $scope.submitForm = function () {

         // check to make sure the form is completely valid
         if ($scope.signup_form.$valid) {
             alert('our form is amazing');
         }

     };

 });