JaVa ScRiPt & JqUeRy

THE DOCUMENT OBJECT REPRESENTS AN HTML PAGE

By using the document object, you can edit, add and delete of any contents that the users can see and to manage how they interact with it.

Today we are going to speak about document object and its main features.

1. Properties

it describes characteristics of the current web page (such as the title of the page)

2. METHODS

it performs tasks the related with the documents that already loaded in the browsers.

3. Events

By responding to events, when a user make a click or tapping on an element or a button in the webiste

People who already have created a browsers will have:

1. Implemented properties that you can access to find out about the current page in the browser

2. Written methods that achieve some common tasks that you are likely to want to do with an HTML page

HOW A BROWSER SEES A WEB PAGE

You need to understand and to know how a browser interprets the HTML code and applies its style in order to know how you can change the content of any HTML.

The following information below will help you with that

1. RECEIVE A PAGE AS HTML CODE

2. CREATE A MODEL OF THE PAGE AND STORE IT IN MEMORY

3. USE A RENDERING ENGINE TO SHOW THE PAGE ON SCREEN

Special Note

all major browsers use a JavaScript interpreter to translate your instructions (in JavaScript) into instructions the computer can follow.

HOW HTML, CSS, & JAVASCRIPT FIT TOGETHER

Web developers usually talk about three languages that are used to create web pages: HTML, CSS, and JavaScript.	Where possible, aim to keep the three languages in separate files with the HTML page linking to CSS and JavaScript files
Each language forms a separate layer with a different purpose. Each layer, from left to right. builds on the previous one

Layer Type	files
CONTENT LAYER	html files This is where the content of the page lives. The HTML gives the page structure and adds semantics.
PRESENTATION LAYER	css files The CSS enhances the HTML page with rules that state how the HTML content is presented (backgrounds, borders, box dimensions, colors, fonts, etc.)
BEHAVIOR layer	.js files This is where we can change how the page behaves, adding interactivity. We will aim to keep as much of our JavaScript as possible in separate files.

PROGRESSIVE ENHANCEMENT

These three layers form the basis of a popular approach to building web pages called progressive enhancement. see the picture below.