BackboneJS - Collection Extend


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Description

It extends the backbone's collection class to create an own collection.

Syntax

Backbone.Collection.extend(properties, classProperties)

Parameters

  • properties − It provides instance properties for the collection class.

  • classProperties − Class properties are attached to the collection's constructor function.

Example

<!DOCTYPE html>
<html>
   <head>
      <title>Collection 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">
      
         //The model 'MyTeam' includes default values and  extended using the 
         //Backbone.Model class
         var MyTeam = Backbone.Model.extend ({
            defaults: {
               player: "sachin",
               country: "india"
            },
         });
         //'MyTeam1' is an instance of the collection
         var MyTeam1 = Backbone.Collection.extend ({
            
            //model 'MyTeam' is specified for a collection by overriding the 
            //'model' property
            model: MyTeam
         });

         //The collection 'MyTeam1' is instantiated by using new keyword
         var myval = new MyTeam1({});

         //The JSON.stringify() method returns values of collection in the JSON format
         document.write("The values in the collection are: ",JSON.stringify(myval));
      </script>
      
   </body>
</html>

Output

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

  • Save the above code in the extend.htm file.

  • Open this HTML file in a browser.

backbonejs_collection.htm
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