Angular ng-messages: how to check password confirmation?

Question

Angular ng-messages: how to check password confirmation?

THE SITUATION:

I am using ng-messages directive for instant validation in my angular app. Everything is working fine except one thing: i need to validate the field 'password confirmation' and don't know how to do.

THE CODE:

<form name="autentication_form" novalidate="" ng-submit="submit_register()">

    <label class="item item-input">
        <span class="input-label">Email</span>
        <input type="text" name="email" ng-model="registerData.email" required>

        <div class="form-errors" ng-messages="autentication_form.email.$error" role="alert" ng-if='autentication_form.email.$dirty'>
            <div class="form-error" ng-message="required">You did not enter the email</div>
        </div>
    </label>

    <label class="item item-input">
        <span class="input-label">Password</span>
        <input type="password" name="password" ng-model="registerData.password" required>

        <div class="form-errors" ng-messages="autentication_form.password.$error" role="alert" ng-if='autentication_form.password.$dirty'>
            <div class="form-error" ng-message="required">Please enter the password</div>
        </div>
    </label>

    <label class="item item-input">
        <span class="input-label">Password confirmation</span>
        <input type="password" name="password_confirmation" ng-model="registerData.password_confirmation" required>

        <div class="form-errors" ng-messages="autentication_form.password_confirmation.$error" role="alert" ng-if='autentication_form.password_confirmation.$dirty'>
            <div class="form-error" ng-message="required">Password confirmation required</div>
        </div>
    </label>

</form>

THE QUESTION:

How can i check that the password confirmation match using ng-messages?

javascript
angularjs
validation
ionic-framework
ng-messages

Answer 1

Require the ngModel controller.

Add a method to the ngModel controller’s $validators object. Angular will invoke the function when the model value changes. The function returns a boolean, and a return value of false will set the corresponding ngModel’s $error property automatically.

The compare-to directive looks like the following:

var compareTo = function() {
    return {
        require: "ngModel",
        scope: {
            otherModelValue: "=compareTo"
        },
        link: function(scope, element, attributes, ngModel) {

            ngModel.$validators.compareTo = function(modelValue) {
                return modelValue == scope.otherModelValue;
            };

            scope.$watch("otherModelValue", function() {
                ngModel.$validate();
            });
        }
    };
};

module.directive("compareTo", compareTo);

You can use the directive inside of markup like so:

<input type="password" name="confirmPassword" 
        ng-model="registration.user.confirmPassword"
        required 
        compare-to="registration.user.password" />

<div ng-messages="registrationForm.confirmPassword.$error"
      ng-messages-include="messages.html"></div>

Answer 2

The best approach is to use a directive. The major point of problem here is that both password and password confirmation inputs need to be watched.

Here's the solution that could help

angular.module('app', ['ngMessages'])

.controller('ctrl', function($scope) {
  $scope.registerData = {};
})


.directive('confirmPwd', function($interpolate, $parse) {
  return {
    require: 'ngModel',
    link: function(scope, elem, attr, ngModelCtrl) {

      var pwdToMatch = $parse(attr.confirmPwd);
      var pwdFn = $interpolate(attr.confirmPwd)(scope);

      scope.$watch(pwdFn, function(newVal) {
          ngModelCtrl.$setValidity('password', ngModelCtrl.$viewValue == newVal);
      })

      ngModelCtrl.$validators.password = function(modelValue, viewValue) {
        var value = modelValue || viewValue;
        return value == pwdToMatch(scope);
      };

    }
  }
});

<html ng-app="app">

<head>
  <script data-require="angular.js@~1.4.3" data-semver="1.4.3" src="https://code.angularjs.org/1.4.3/angular.js"></script>
  <script data-require="angular-messages@1.4.3" data-semver="1.4.3" src="https://code.angularjs.org/1.4.3/angular-messages.js"></script>
  <script src="https://code.angularjs.org/1.3.15/angular.js"></script>
  <script src="script.js"></script>
</head>

<body ng-controller="ctrl">
  <form name="autentication_form" novalidate="" ng-submit="submit_register()">
    <label class="item item-input">
      <span class="input-label">Email</span>
      <input type="text" name="email" ng-model="registerData.email" required="" />
      <div class="form-errors" ng-messages="autentication_form.email.$error" ng-if='autentication_form.email.$touched'>
        <span class="form-error" ng-message="required">You did not enter the email</span>
      </div>
    </label>
    <label class="item item-input">
      <span class="input-label">Password</span>
      <input type="password" name="password" ng-model="registerData.password" required />
      <div class="form-errors" ng-messages="autentication_form.password.$error" ng-if='autentication_form.password.$touched'>
        <span class="form-error" ng-message="required">Please enter the password</span>
      </div>
    </label>
    <label class="item item-input">
      <span class="input-label">Password confirmation</span>
      <input type="password" name="password_confirmation" ng-model="registerData.password_confirmation" required="" confirm-pwd="registerData.password" />
      <div class="form-errors" ng-messages="autentication_form.password_confirmation.$error" ng-if='autentication_form.password_confirmation.$touched'>
        <span class="form-error" ng-message="required">Password confirmation required</span>
        <span class="form-error" ng-message="password">Password different</span>
      </div>
    </label>
  </form>
</body>

</html>