Backbone.sync()

Backbone.sync is a function that is called every time when Backbone.js tries to read or save a model to the server. It is used to display the state of the model.

Syntax:

Parameter explanation:

method: It specifies the CRUD methods i.e. create, read, update and delete.

model: It specifies the model to be saved or collection to be read.

options: It displays success or error message depending on the method succeeded.

Let's take an example.

See this example:

 <!DOCTYPE html>
   <head>
      <title>Sync 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">
         Backbone.sync = function(method, model) {
            document.write("See the state of the model:");
            document.write("<br>");

            document.write(method + ": " + JSON.stringify(model));
         };

         var myval = new Backbone.Collection({
            site:"JavaTpoint",
            title:"A solution of all technology..."
         });

         myval.fetch();
         </script>
         </body>
      </html>

Test it Now

Output:

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