BackboneJS-Model previousAttributes

Description

It returns copy of the model's previous attributes prior to last change event. This is useful for getting a diff between versions of a model, or getting back to a valid state after an error occurs.

Syntax

model.previousAttributes()

Example

<!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>
   </head>
   <body>
   <script type="text/javascript">
      var model = new Backbone.Model({
         id:01,
         player:'Sachin',
         country:'India'
      });
      model.set('id', '02');
      document.write("All the attributes returned by the previousAttributes() method are: ");
      document.write("<br>");
      document.write(JSON.stringify(model.previousAttributes()));
   </script>
   </body>
</html>

Output

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

  • Save above code in previousAttributes.htm file

  • Open this HTML file in a browser.

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