Backbone.js Event on()

The Event on method is used to bind an event to an object and callback function. It executes the callback function whenever an event is fired.

Syntax:

Parameter explanation:

event:It is used to bind an object.

callback:It is executed whenever an event is fired. It references to the code.

context: It is an object that can be passed to a callback function.

Let's take an example.

See this example:

<!DOCTYPE html>
   <head>
      <title>Event On Example</title>
         <script src="https://code.jquery.com/jquery-2.1.3.min.js" type="text/javascript"></script>
         <script src="https://cdnjs.cloudflare.com/ajax/libs/underscore.js/1.8.2/underscore-min.js" type="text/javascript"></script>
         <script src="https://cdnjs.cloudflare.com/ajax/libs/backbone.js/1.1.2/backbone-min.js" type="text/javascript"></script>
   </head>
   <body>
      <script type="text/javascript">
      	//Here creating an object 'myVal' and extending with Backbone.Events method
         var myVal = _.extend({name:'Welcome to JavaTpoint'}, Backbone.Events);

         // The on() method will bind callback function to an object and invoked whenever an event triggers
         myVal.on('myFunc', function () {
            document.write("The triggered value is: ");
            document.write(this.name);
         });
         //It triggers the 'myFunc' event on object 'myVal'
         myVal.trigger('myFunc');
      </script>
   </body>
</html>

Test it Now

Output:

Save the above code in on.html file and open this file in a browser.