BackboneJS-Model previousAttributes


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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.

backbonejs_model.htm
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