ng-change in Angular 8

Angular 8 is a popular framework for building dynamic web applications, and one of its key features is the ability to handle user input using directives such as ng-change. In this article, we will explore the ng-change directive and how it can be used in Angular 8.

The ng-change Directive

The ng-change directive is used to execute a function when the value of an input element is changed by the user. It is commonly used with input elements such as textboxes, checkboxes, and radio buttons.

In Angular 8, the syntax for using ng-change is as follows:

<input type="text" ng-change="myFunction()" ng-model="myValue">

In the above example, when the value of the textbox changes, the function myFunction() will be executed. The ng-model directive is used to bind the value of the input element to a variable in the controller.

Using ng-change in Angular 8

Let's take a look at an example of ng-change in Angular 8:

<div ng-app="myApp" ng-controller="myCtrl">
  <input type="text" ng-model="name" ng-change="updateName()">
  <p>{{ greeting }}</p>
</div>

<script>
  var app = angular.module("myApp", []);
  app.controller("myCtrl", function($scope) {
    $scope.name = "David";
    $scope.updateName = function() {
      $scope.greeting = "Hello " + $scope.name + "!";
    }
  });
</script>

In the above example, we have an input element with ng-model set to "name" and ng-change set to "updateName()". When the user changes the value of the input element, the updateName() function is executed, which sets the value of the greeting variable to "Hello David!". The value of greeting is then displayed in a paragraph element using the AngularJS expression {{ greeting }}.

Conclusion

The ng-change directive is a powerful feature in Angular 8 that allows developers to easily handle user input in their web applications. By using ng-change, developers can execute functions in response to user actions, making their applications more dynamic and user-friendly.