bootstrap-validation.directive.js

(function(){
   'use strict';

   function createWatchExpression(formName) {
      var props = ['$pristine', '$dirty', '$valid', '$pending', '$submitted'];

      return _.map(props, function (prop) {
         return formName + "." + prop;
      });
   }

   function BootstrapValidationDirective() { 
      return {
         restrict: 'A',
         require: 'form',
         link: function (scope, elem, attrs, formCtrl) {
            scope.$watchGroup(createWatchExpression(formCtrl.$name), function () {
               var inputs = elem.find('input');

               angular.forEach(inputs, function (input) {
                  var control = formCtrl[$(input).attr('name')];
                  var parent = $(input).parent();

                  if (control) {
                     parent.toggleClass('has-error', control.$invalid);
                  }
               });
            });
         }
      };
   }

   angular.module('my-app')
      .directive('bsValidation', BootstrapValidationDirective);

}());

example.html

<form name="ctrl.userForm" bs-validation>
  <div class="form-group">
      <label class="control-label">First Name</label>
      <input type="text" name="Firstname" class="form-control" placeholder="First Name" ng-model="ctrl.user.Firstname">
  </div>
  <div class="form-group">
      <label class="control-label">Last Name</label>
      <input type="text" name="Lastname" class="form-control" placeholder="Last Name" ng-model="ctrl.user.Lastname">
  </div>
</form>