Page 175 - DCAP408_WEB_PROGRAMMING

Mandeep Kaur, Lovely Professional University Unit 6: DOM Model

Unit 6: DOM Model Notes

CONTENTS
Objectives
Introduction

6.1 DOM Model
6.1.1 The JavaScript Assisted Style Sheets DOM (JSSS DOM)
6.2 Events Handling through JavaScript

6.2.1 Event Association
6.3 How to use Forms in JavaScript
6.3.1 Form Validation with JavaScript
6.4 Summary
6.5 Keywords

6.6 Review Questions
6.7 Further Readings

Objectives

After studying this unit, you will be able to:

 Recognize the DOM model
 Describe event handling through JavaScript
 Demonstrate how to use forms in JavaScript

Introduction

An HTML page is rendered (painted) in a browser. The browser assembles all the elements
(objects) contained in the HTML page, downloaded from the web server, in its memory. Once,
done the browser then renders these objects in the browser window. Once, the HTML page is
rendered in the browser window, the browser can no longer recognize individual HTML elements
(objects).

To create an interactive web page, it is imperative that the browser continues to recognize
individual HTML objects even after they are rendered in the browser window. This allows the
browser to access the properties of these objects using the built-in methods of the object. Once
the properties of an object are accessible then the functionality of the object can be controlled at
will.

6.1 DOM Model

JavaScript enabled browsers are capable of recognizing individual objects in an HTML page,
after the page has been rendered in the browser, because the JavaScript enabled browser
recognizes and uses the Document Object Model (DOM).

LOVELY PROFESSIONAL UNIVERSITY 169