Backbone.js extend() Model
The Backbone.js extend Model is used to extend the backbone’s Model class in which we can create our own Model. It also facilitates the instance properties & the optional classProperties that are attached to the constructor function of the Model directly. Extend method of the model create a prototype chain, so subclass created with extend can be further extended and subclassed as far as you like.
Syntax:
Backbone.Model.extend( Properties, classProperties );
Parameters: It accepts two parameters that are described below:
- Parameters: This parameter provides the instance properties for the specified collection class.
- classProperties: This class property is attached to the collection’s constructor function.
Example 1: In this example, we will extend a Model with some default values.
HTML
<!DOCTYPE html>
< html >
< head >
< title >BackboneJS Model extend</ title >
< script src =
</ script >
< script src =
type = "text/javascript" >
</ script >
< script src =
type = "text/javascript" >
</ script >
</ head >
< body >
< h1 style = "color: green;" >
GeeksforGeeks
</ h1 >
< h3 >BackboneJS Model extend</ h3 >
< script type = "text/javascript" >
var model = Backbone.Model.extend({
defaults: {
id: 1,
name: 'Geeks'
},
});
var temp = new model();
document.write(JSON.stringify(temp));
</ script >
</ body >
</ html >
|
Output:
Backbone.Model.extend()
Example 2: In this example, we will make a chain of extend function and see the properties of each object. Extend method of model create a prototype chain, so subclass created with extend can be further extended and subclassed as far as you like.
HTML
<!DOCTYPE html>
< html >
< head >
< title >BackboneJS Model extend</ title >
type = "text/javascript" >
</ script >
< script src =
type = "text/javascript" >
</ script >
< script src =
type = "text/javascript" >
</ script >
</ head >
< body >
< h1 style = "color: green;" >
GeeksforGeeks
</ h1 >
< h3 >BackboneJS Model extend chaining</ h3 >
< script type = "text/javascript" >
var model = Backbone.Model.extend({
defaults: {
id: -1,
name: 'Geeks'
},
});
var temp = new model();
document.write(JSON.stringify(temp));
var model2 = model.extend({
initialize: function () {
document.write(
"< br > This function is extend by second extend");
},
});
var temp2 = new model2({ id: 2, name: 'cody' });
document.write("< br >", JSON.stringify(temp2));
</ script >
</ body >
</ html >
|
Output:
Model.extend() chaining
Reference: https://backbonejs.org/#Model-extend
Last Updated :
14 Jul, 2022
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