Technologies Post: AngularJS Form Validation

Wednesday, 23 July 2014

AngularJS Form Validation

Angularjs providing form validation facility, so that the user can be notified of invalid input. This provides a safer user experience, because the user receives instant feedback on how to rectify the mistake. Maintain in brain that while client-side validation plays an important part in providing a good user experience, it can easily be circumvented and thus can not be trusted. Server-side validation is still necessary for a secure application.

We need 2 files

Formvalidation.html
app.js

Formvalidation.html

 <!DOCTYPE html>  
 <html>  
 <head>  
   <!-- CSS -->  
   <!-- load bootstrap -->  
   <link rel="stylesheet" href="css/bootstrap.min.css">   
   <style>  
        body      { padding-top:30px; }  
   </style>  
   <!-- JS -->  
   <!-- load angular -->  
   <script src="js/anguler_1.2.js"></script>   
   <script src="js/app.js"></script>  
 </head>  
 <!-- apply angular app and controller to our body -->  
 <body ng-app="formValidationApp" ng-controller="formController">  
 <div class="container">  
 <div class="col-sm-8 col-sm-offset-2">  
   <!-- PAGE HEADER -->  
   <div class="page-header"><h3>AngularJS Form Validation with HTML5</h3></div>  
   <!-- FORM -->  
   <!-- novalidate is used to disable browser's native form validation -->  
   <form name="userForm" ng-submit="submitForm(userForm.$valid)" novalidate>   
     <!-- NAME -->  
     <div class="form-group">  
       <label>Name *</label>  
       <input type="text" name="name" class="form-control" ng-model="name" required>  
       <p ng-show="userForm.name.$invalid && !userForm.name.$pristine" class="help-block">You name is required.</p>  
     </div>  
     <!-- USERNAME -->  
     <div class="form-group">  
       <label>Username</label>  
       <input type="text" name="username" class="form-control" ng-model="user.username" ng-minlength="3" ng-maxlength="8" required>  
       <p ng-show="userForm.username.$error.minlength" class="help-block">Username is too short.</p>  
       <p ng-show="userForm.username.$error.maxlength" class="help-block">Username is too long.</p>  
       <p ng-show="userForm.username.$invalid && !userForm.username.$pristine" class="help-block">Please enter Username</p>  
     </div>  
     <!-- EMAIL -->  
     <div class="form-group">  
       <label>Email</label>  
       <input type="email" name="email" class="form-control" ng-model="email">.  
       <p ng-show="userForm.email.$invalid && !userForm.email.$pristine" class="help-block">Enter a valid email.</p>  
     </div>  
     <!-- SUBMIT BUTTON -->  
     <button type="submit" class="btn btn-primary">Submit</button>  
   </form>  
 </div><!-- col-sm-8 -->  
 </div><!-- /container -->  
 </body>  
 </html>

A few central stops to notice here

novalidate is used to disable browser's native form validation

The ngModel directive provides the two-way data-binding by synchronizing the model to the view, as well as view to the model

app.js

 //app.js  
 // create angular app  
 var formValidationApp = angular.module('formValidationApp', []);  
 // create angular controller  
 formValidationApp.controller('formController', function($scope) {  
   // function to submit the form after all validation has occurred                 
   $scope.submitForm = function(isValid) {  
     // check to make sure the form is completely valid  
     if (isValid) {  
       alert('our form is amazing');  
     } else {  
       alert("All values are not filled Please check")  
     }  
   };  
 });