The ng-disabled directive in Angular JS is not effectively disabling a button

Question

The ng-disabled directive in Angular JS is not effectively disabling a button

Why is the button not disabled?

var mainApp = angular.module('mainApp', []);
mainApp.controller('mainController', function ($scope) {
    $scope.form = {
        login: ''
    };
});

<form ng-controller="LoginAppCtrl as lc" ng-app="MTApp">
  <div class="login">
    <h1>LOG IN</h1>
  </div>
  <div>
    <div>User Name :</div>
    <div>
      <input type="text" name="tbUserName" required ng-model="lc.request.user">
    </div>
  </div>

  <div>
    <div>Password :</div>
    <div>
      <input type="text" name="tbPassword" required ng-model="lc.request.password">
    </div>
  </div>
  <div>
    <div>
      <button ng-click="lc.submitRequest()" ng-disabled="lc.request.user == '' || lc.request.password == '' ">Sign In</button>
    </div>
  </div>
</form>

I'm a beginner in Angular JS and I'm attempting to create a basic login form. If the login is successful, another form will be shown, if not, the login form will remain. Can someone provide some assistance? I am in need of some basic tutorials.

javascript angularjs

Answer 1

Answer №1

There are a few errors in your code that you need to address:

Firstly, the module declaration should match the ng-app attribute. Instead of declaring it as 'mainApp', it should be ng-app="mainApp".

Similarly, the controller declaration and ng-controller attribute should also match.

Secondly, if 'request' is an object, make sure to initialize it in your controller:

$scope.request = {};

Thirdly, ensure to check for undefined as well, not just an empty string:

ng-disabled="!request.user || !request.password"

Refer to this Fiddle for the complete code and HTML.

Answer 2

There are a few errors in your code that you need to address:

Firstly, the module declaration should match the ng-app attribute. Instead of declaring it as 'mainApp', it should be ng-app="mainApp".

Similarly, the controller declaration and ng-controller attribute should also match.

Secondly, if 'request' is an object, make sure to initialize it in your controller:

$scope.request = {};

Thirdly, ensure to check for undefined as well, not just an empty string:

ng-disabled="!request.user || !request.password"

Refer to this Fiddle for the complete code and HTML.

Answer 3

Answer №2

There are two ways to disable button functionality:

1) Without involving the controller object, you can disable the button based on the values in the text boxes. Give a name to the form element like:

<form name='form1'>
  <div>
    <div>User Name :</div>
      <input type="text" name="tbUserName" required ng-model="lc.request.user">
  </div>
  <div>
    <div>Password :</div>
      <input type="text" name="tbPassword" required ng-model="lc.request.password">
  </div>
  <div>
    <button ng-disabled="form1.$invalid">Sign In</button>
  </div>
</form>

2) Alternatively, you can disable the button based on an object defined in the controller:

If you have an object in your controller, for example:

$scope.user = {name:'', password:''}

Then you can use ng-model='user.name' and ng-model = 'user.password' for the input boxes. The submit button can be disabled using:

ng-disabled=" user.name === '' || user.password === '' "

<form>
  <div>
    <div>User Name :</div>
      <input type="text" name="tbUserName" required ng-model="user.name">
  </div>
  <div>
    <div>Password :</div>
      <input type="text" name="tbPassword" required ng-model="user.password">
  </div>
  <div>
    <button ng-disabled="user.name==='' || user.password===''">Sign In</button>
  </div>
</form>

Make sure the controller has the object defined:

app.controller('MainCtrl', function($scope) {
  $scope.name = 'World';
  $scope.user = {name:'',password:''};
});

Is this what you were looking for?

Answer 4

There are two ways to disable button functionality:

1) Without involving the controller object, you can disable the button based on the values in the text boxes. Give a name to the form element like:

<form name='form1'>
  <div>
    <div>User Name :</div>
      <input type="text" name="tbUserName" required ng-model="lc.request.user">
  </div>
  <div>
    <div>Password :</div>
      <input type="text" name="tbPassword" required ng-model="lc.request.password">
  </div>
  <div>
    <button ng-disabled="form1.$invalid">Sign In</button>
  </div>
</form>

2) Alternatively, you can disable the button based on an object defined in the controller:

If you have an object in your controller, for example:

$scope.user = {name:'', password:''}

Then you can use ng-model='user.name' and ng-model = 'user.password' for the input boxes. The submit button can be disabled using:

ng-disabled=" user.name === '' || user.password === '' "

<form>
  <div>
    <div>User Name :</div>
      <input type="text" name="tbUserName" required ng-model="user.name">
  </div>
  <div>
    <div>Password :</div>
      <input type="text" name="tbPassword" required ng-model="user.password">
  </div>
  <div>
    <button ng-disabled="user.name==='' || user.password===''">Sign In</button>
  </div>
</form>

Make sure the controller has the object defined:

app.controller('MainCtrl', function($scope) {
  $scope.name = 'World';
  $scope.user = {name:'',password:''};
});

Is this what you were looking for?

The ng-disabled directive in Angular JS is not effectively disabling a button

Answer №1

Answer №2

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