Backbone.JS Sync() collection

The Backbone.JS Sync() collection method is used to specify the state of the model and to display the state of the collection.

Syntax:

Backbone.Collection.Sync ( method, collection, options )   

Parameters:
method: This parameter is used to specify the CRUD operations: create, read, update and delete.
collection: This parameter is used to specify the collection containing a set of models.
options: This parameter is used to specify the success or error messages.

Example:

<!DOCTYPE html>  
<html>
<head>  
<title>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("Model state:");  
document.write("<br>");  
document.write(method + ": " + JSON.stringify(model));  
};  
var X = new Backbone.Collection({  
name: "Tom",  
age: 20
});   
X.fetch();  
</script>  
</body>  
</html>

Output:

Model state:
read: [{"name":"Tom","age":20}]

Explanation:
In the above example, sync() method reads and fetches the model data while the fetch() method display the model’s state by delegating the sync() method.

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