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angularjsHow can I implement form validation in an AngularJS application?


Form validation in an AngularJS application can be implemented using the built-in $validators service. The $validators service allows you to define custom validators that can be used for any form field.

The following example shows how to define a custom validator for a text field:

// Create a custom validator
var validator = function(value) {
  if (value.length < 5) {
    return false;
  }
  return true;
};

// Use the validator on the text field
$validators.myValidator = validator;

In the above example, the custom validator myValidator will be used to validate the text field. If the value of the text field is less than 5 characters, the validator will return false.

To use the validator in an AngularJS application, the ng-model directive can be used. The following example shows how to use the validator on a text field:

<input type="text" ng-model="myField" validator="myValidator">

In the above example, the ng-model directive is used to bind the text field to the myField model. The validator attribute is used to specify the validator to be used for the field.

The custom validator can also be used with the ng-form directive. The following example shows how to use the validator with the ng-form directive:

<form ng-form="myForm" validator="myValidator">
  ...
</form>

In the above example, the ng-form directive is used to bind the form to the myForm model. The validator attribute is used to specify the validator to be used for the form.

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