Chapter 6: Clientside dynamics pages pdf

Client-side dynamic pages JavaScript... Javascript, VBscript Javascript: Netscape.. Applet: Advantage/disadvantage Advantages of Applet: Applets are cross platform and can run on Wind

Chapter 6: side dynamics

Client-pages

Client-side dynamic pages

JavaScript

Client-side dynamic pages

executed in the client side by browser.

Javascript, VBscript

 Javascript:

Netscape

compiled languages such as C and C++

very useful for shorter programs

 Vbscript

mozila and internet explorer

access system resources on the local computer

Applet: Advantage/disadvantage

Advantages of Applet:

 Applets are cross platform and can run on Windows, Mac OS and Linux platform

 Applets can work all the version of Java Plugin

 Applets runs in a sandbox, so the user does not need to trust the code,

so it can work without security approval

 Applets are supported by most web browsers

 Applets are cached in most web browsers, so will be quick to load when returning to a web page

 User can also have full access to the machine if user allows

Disadvantages of Java Applet:

 Java plug-in is required to run applet

 Java applet requires JVM so first time it takes significant startup time

 If applet is not already cached in the machine, it will be downloaded

from internet and will take time

 Its difficult to desing and build good user interface in applets

 Previously called Macromedia Flash

pages

web page components, to integrate video into web pages, and morerecently, to develop rich Internet applications

because:

 Flash movies load faster and save on download time because Flash is vector based whereas HTML is not

 Flash intelligently ‘caches’ it’s movies so they don’t have to be reloaded

 Flash gives the user (the person viewing/using the Flash movie) a more responsive ‘rich-client’ like experience

Javascript allows:

Ex: code to virsualise the current time

Put Javascript into HTML

Function call is put inside <script> … </script>

Data type in Javascript

Basic data type

Contain basic character

Variable in Javascript

 Like a variable in other programming language

 Data type is not defined at variable declaration

 String

 Array

Operators, Control Structure

Same syntax as Java

Function in Javascript

Function

Function in Javascript

Declaration of a function with parameters

function function_name (param_1, param_2, … param_n){

Event of closing a webpage

Mouse related event

Call a javascript function by an event