BackboneJS-Model hasChanged

Description

It returns true if attribute gets changed since the last set.

Syntax

model.hasChanged(attribute)

Parameters

attribute − It defines property of a model.

Example

Live Demo

<!DOCTYPE html>
   <head>
      <title> Model 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>
         
      <script type = "text/javascript">
         var person = new Backbone.Model({
            name: 'john'
         });
         document.write('Has name changed (before set) = ' + person.hasChanged());
         person.set('name', 'smith', {silent: true});
         document.write('<br>Has name changed (after set) =' + 
            person.hasChanged());
      </script>
   </head>
   
   <body></body>
</html>

Output

Let's carry out the following steps to see how above code works −

Save above code in hasChanged.htm file
Open this HTML file in a browser.

backbonejs_model.htm