Avoid activating form.$invalid when the form loads for the first time

Question

Avoid activating form.$invalid when the form loads for the first time

Dealing with this particular structure

    <div ng-controller="FormController as f_ctrl">
    <form ng-submit="f_ctrl.submit()" name="myForm">
    <input type="text" ng-model="f_ctrl.user.username"
            required
            ng-minlength="4"/>
    <input type="text" ng-model="f_ctrl.user.password"/>
    <input type="submit" value="Submit" ng-disabled="myForm.$invalid">
    </form>
</div>

With the following controller setup

    .controller('FormController', [function() {
    var self = this;

    self.submit = function() {
        console.log('User submitted form with ' + self.user.username)
    }
}]);

I am encountering an issue: upon initial page load, there is already a noticeable red border around the username field, even though I have not started entering any text yet. I would like to only highlight invalid fields after the first submission. Is there a way to achieve this using form.$invalid ?

javascript angularjs forms angularjs-directive angularjs-forms

Answer 1

Answer №1

To achieve this, you need to utilize $pristine. This attribute is true when the form controller has not been altered. Therefore, if you modify the data in a textbox, it will become false.

Here's a small example for better understanding:

<div class="form-group" ng-class="{ 'has-error' : userForm.password.$invalid && !userForm.password.$pristine }">
    <input id="passAnime" type="password" name="password" ng-model="user.password" class="form-control input-md" placeholder="Password" tabindex="5" ng-maxlength="25" ng-minlength="6" required>

    <span ng-show="userForm.password.$dirty && userForm.password.$invalid">
        <p ng-show="userForm.password.$error.required" class="error-messages">
             Your password is required.
        </p>
        <p ng-show="userForm.password.$error.minlength" class="error-messages">
            Your password is too short. Minimum of 6 characters required.
        </p>
        <p ng-show="userForm.password.$error.maxlength" class="error-messages">
            Your password is too long. Maximum of 25 characters allowed.
        </p>
    </span>
</div>

Answer 2

To achieve this, you need to utilize $pristine. This attribute is true when the form controller has not been altered. Therefore, if you modify the data in a textbox, it will become false.

Here's a small example for better understanding:

<div class="form-group" ng-class="{ 'has-error' : userForm.password.$invalid && !userForm.password.$pristine }">
    <input id="passAnime" type="password" name="password" ng-model="user.password" class="form-control input-md" placeholder="Password" tabindex="5" ng-maxlength="25" ng-minlength="6" required>

    <span ng-show="userForm.password.$dirty && userForm.password.$invalid">
        <p ng-show="userForm.password.$error.required" class="error-messages">
             Your password is required.
        </p>
        <p ng-show="userForm.password.$error.minlength" class="error-messages">
            Your password is too short. Minimum of 6 characters required.
        </p>
        <p ng-show="userForm.password.$error.maxlength" class="error-messages">
            Your password is too long. Maximum of 25 characters allowed.
        </p>
    </span>
</div>

Answer 3

Answer №2

Angular provides useful tools to determine if a form (or form field) is $dirty (user has entered data) or if the form is $touched (the input has been blurred). View a demonstration here.

I want to highlight invalid fields only after the first submission.

Regrettably, Angular does not have built-in support for this feature. However, you can easily implement it yourself:

Controller

function FormController() {
  var vm = this;
  vm.submitAttempted = false;
  vm.submit = function(isValid) {
    if (isValid) {
      // perform actions
    } else {
      vm.submitAttempted = true;
    }
  };
}

HTML

<div ng-app='app'>
  <div ng-controller='FormController as vm'>
    <form name='fooForm' ng-submit='vm.submit(fooForm.$valid)' novalidate>
      <label>Username</label>
      <input 
        name='username' 
        type='text' 
        ng-model='vm.user.username'
        required
        ng-minlength='4'
        ng-class="{'invalid': vm.submitAttempted && fooForm.username.$invalid}">
      <br /><br />
      <button type='submit'>Submit</button>
    </form>
  </div>
</div>

CSS

.invalid {
  border-color: red;
}

View Demo

I am facing an issue: upon page load, the username field immediately displays a red border even before any text is inputted.

This may be due to the presence of the following CSS class:

.ng-invalid {
  border-color: red;
}

Angular will consistently assign the ng-invalid class to invalid fields, which cannot be altered. If you do not want all invalid fields to always have a red border, avoid using that class and follow a similar approach outlined above.

Additionally, explore ngMessages.

Answer 4

Angular provides useful tools to determine if a form (or form field) is $dirty (user has entered data) or if the form is $touched (the input has been blurred). View a demonstration here.

I want to highlight invalid fields only after the first submission.

Regrettably, Angular does not have built-in support for this feature. However, you can easily implement it yourself:

Controller

function FormController() {
  var vm = this;
  vm.submitAttempted = false;
  vm.submit = function(isValid) {
    if (isValid) {
      // perform actions
    } else {
      vm.submitAttempted = true;
    }
  };
}

HTML

<div ng-app='app'>
  <div ng-controller='FormController as vm'>
    <form name='fooForm' ng-submit='vm.submit(fooForm.$valid)' novalidate>
      <label>Username</label>
      <input 
        name='username' 
        type='text' 
        ng-model='vm.user.username'
        required
        ng-minlength='4'
        ng-class="{'invalid': vm.submitAttempted && fooForm.username.$invalid}">
      <br /><br />
      <button type='submit'>Submit</button>
    </form>
  </div>
</div>

CSS

.invalid {
  border-color: red;
}

View Demo

I am facing an issue: upon page load, the username field immediately displays a red border even before any text is inputted.

This may be due to the presence of the following CSS class:

.ng-invalid {
  border-color: red;
}

Angular will consistently assign the ng-invalid class to invalid fields, which cannot be altered. If you do not want all invalid fields to always have a red border, avoid using that class and follow a similar approach outlined above.

Additionally, explore ngMessages.

Answer 5

Answer №3

If you want to remove the default styling on the input field that adds a red border, you can do so by implementing the following CSS:

input:required {
    -moz-box-shadow: none;
    box-shadow: none;
}

To highlight the field when the form is submitted, make sure to assign relevant name attributes to the form and form fields. This way, you can verify if the field is valid and apply a class to your text field if it is invalid:

<input type="text" name="username" ng-class="{ 'invalid-field' : f_ctrl.myForm.username.$invalid && !f_ctrl.myForm.username.$pristine }" required />

f_ctrl.myForm and f_ctrl.myform.username will contain extra properties that can help you determine the validity of the form or fields, as well as whether they have been altered in any way (e.g. f_ctrl.myform.username.$dirty). You can display these properties on your page by adding the following HTML:

<div>
    <pre>{{f_ctrl.myForm | json}}</pre>
</div>

Alternatively, you can output self.myForm to the console from your controller to inspect its properties:

console.log(self.myForm);

Answer 6

If you want to remove the default styling on the input field that adds a red border, you can do so by implementing the following CSS:

input:required {
    -moz-box-shadow: none;
    box-shadow: none;
}

To highlight the field when the form is submitted, make sure to assign relevant name attributes to the form and form fields. This way, you can verify if the field is valid and apply a class to your text field if it is invalid:

<input type="text" name="username" ng-class="{ 'invalid-field' : f_ctrl.myForm.username.$invalid && !f_ctrl.myForm.username.$pristine }" required />

f_ctrl.myForm and f_ctrl.myform.username will contain extra properties that can help you determine the validity of the form or fields, as well as whether they have been altered in any way (e.g. f_ctrl.myform.username.$dirty). You can display these properties on your page by adding the following HTML:

<div>
    <pre>{{f_ctrl.myForm | json}}</pre>
</div>

Alternatively, you can output self.myForm to the console from your controller to inspect its properties:

console.log(self.myForm);

Avoid activating form.$invalid when the form loads for the first time

Answer №1

Answer №2

Answer №3

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