JavascriptClient Side ScriptingHerman Tolle, ST., MT - (herman_tolle@yahoo.com)

Web DinamisWebsite yang dinamis menyediakan

interaksi antara pengguna dengan halaman web

Interaktifitas tidak didapatkan pada dokumen yang murni HTML saja.

Kemampuan pemrograman dapat ditambahkan pada dokumen web untuk interaktifitas

Why JavaScript?Web application round-trip expensive

no way to do computation on the client sideexample: form validation

Web pages staticno way to allow users to interact with the

pageexample: popup link menus

What is neededclient-side code

Pemrograman WebClient Side Script : Script yang ditambahkan dalam dokumen

html, dieksekusi oleh browser client. Javascript, Jscript, VBScriptServer Side Script: Script yang ditambahkan dalam dokumen

html, dieksekusi oleh server, hasilnya dalam bentuk html yang dikirim ke client.

ASP/ASP.Net, PHP, CGI, JSP, dll

Pemrosesan Script

Web Browser

(Client side processing)

HTML JavaScript

Java Applets

Web

Server

CGI SSI

Servlet PHP JSP ASP

Databases

HTTP

Server Side Processing

Client Side Script Script yang ditambahkan (embedded) pada

halaman web yang sebelumnya hanya disusun dengan sintaks HTML.

Penambahan script ini mempunyai tujuan tertentu. Misalnya:

menampilkan jam dan tanggal yang up- to-date,

menu yang dinamis (mis: pull down menu), kontrol terhadap sebuah window, animasi sederhana, animasi mouse maupun untuk validasi form, dll

Client Side ScriptAdvantage: Waktu proses relatif cepat karena langsung

dieksekusi oleh browser client Tidak memerlukan web server untuk hosting Dapat dieksekusi langsung oleh berbagai browser

Disadvantage: Script bisa dilihat oleh pengguna Script dapat di copy-paste Tidak cocok untuk akses data atau database

Server Side Script Digunakan untuk membuat aplikasi web atau

konten-konten dinamis: news, buku tamu, dll PHP: open source dan banyak digunakan luas Active Server Pages (ASP) dan ASP.Net,

teknologi yang dikembangkan oleh Microsoft ColdFusion (CFM), dikembangkan oleh

Macromedia Java Server Pages dan Servlet dikembangkan

oleh Sun Microsystem Common Gateway Interface (CGI), yang dibuat

dengan bahasa pemrograman C++ atau Perl Server Side Include (SSI), seperti misalnya

Frontpage Server Extension

Server Side ScriptAdvantage: Script tidak bisa dilihat oleh pengguna, sehingga

tidak dapat di-copy-paste Cocok untuk akses data atau aplikasi database Untuk membuat fitur-fitur tertentu yang berguna,

misalnya: hit counter, user manajemen, disain yang dinamis, CMS, dll

Disdvantage: Waktu proses relatif lebih lambat karena

dieksekusi oleh server Memerlukan web server untuk hosting

JavaScript Very little connection to Java

marketing move by Netscape JavaScript is

a scripting language for web clients interpreted Un-typed

Dynamic HTML combination of JavaScript, CSS and DOM to create very flexible web page presentation

Scripts vs. programsa scripting language is a simple,

interpreted programming languagescripts are embedded as plain text, interpreted by applicationsimpler execution model: don't need compiler or development environmentsaves bandwidth: source code is downloaded, not compiled executableplatform-independence: code interpreted by any script-enabled browserbut: slower than compiled code, not as powerful/full-featured

JavaScript: the first Web scripting language, developed by Netscape in 1995 syntactic similarities to Java/C++, but simpler & more flexible

(loose typing, dynamic variables, simple objects)

JScript: Microsoft version of JavaScript, introduced in 1996 same core language, but some browser-specific differences fortunately, IE & Netscape can (mostly) handle both JavaScript &

JScript

JavaScript 1.5 & JScript 5.0 cores conform to ECMAScript standard

VBScript: client-side scripting version of Microsoft Visual Basic

Java Applet Applets are small applications to run on

client’s machine. It is in separate file than the Web page itself. The downloaded applet executed by the

browser’s built-in interpreter, that reduces the burden on the server.

A Java applet first need to be compiled and needs JDK.

JavaScript is a subset of Java and don’t need to be compiled, it is an interpreted only language.

What's the difference between Java and JavaScript?

Java is completely different from JavaScript Java is a full-fledged, object-oriented prog. lang.

It belongs in the same league as C, C++, and other compiled languages. Also, you need to compile a Java program (using JDK) before you can run it,

whereas with JavaScript, no compilation is needed- simply open up a text editor, type it, save it, and your browser is ready to run it!

Common scripting tasks adding dynamic features to Web pages

validation of form data image rollovers time-sensitive or random page elements handling cookies

defining programs with Web interfaces utilize buttons, text boxes, clickable images, prompts, frames

limitations of client-side scriptingsince script code is embedded in the page,

viewable to the world for security reasons, scripts are limited in what

they can doe.g., can't access the client's hard drive

since designed to run on any machine platform, scripts do not contain platform specific commands

script languages are not full-featurede.g., JavaScript objects are crude, not good for large

project development

JavaScript code can be embedded in a Web page using SCRIPT tags the output of JavaScript code is displayed as if directly entered

in HTML

<html><!-- Dave Reed js01.html 2/06/03 -->

<head> <title>JavaScript Page</title></head>

<body> <script type="text/javascript"> // silly code to demonstrate output

document.write("Hello world!");

document.write("<p>How are <br />" + "<i>you</i>?</p>"); </script>

<p>Here is some static text as well. </p></body></html>

document.write displays text in page

text to be displayed can include HTML tags

the tags are interpreted by the browser when the text is displayed

as in C++/Java, statements end with ;

JavaScript comments similar to C++/Java

// starts a single line comment

/*…*/ enclose multi-line comments

JavaScript Object Reference JavaScript has a wide variety of objects you can use

when programming, and each of them have different properties you can control or display through the use of methods. This list should make your programming jobs in JavaScript a little easier.

Client-side JavaScript objects Anchor, Applet, Array, Boolean, Button, Checkbox, Date, document,

event, FileUpload, form, Frame, Function, Hidden, History, Image, Java, JavaArray, JavaClass, JavaObject, JavaPackage, Layer Link, Location, Math, MimeType, Navigator, netscape, Number, Object, Option, Packages, Password, Plugin, Radio, RegExp, Reset, screen, Select, String, Style, Submit, Sun, Text, Textarea, window.

Tips Client Side Script:Gunakan untuk proses-proses sisi

client Script Javascript mudah untuk

“dibajak”Pelajari bagaimana cara

“menambahkan” ke website kitaSource:

http://www.dynamicdrive.comhttp://www.javascriptsource.com

ReferensiJavaScript Guide from Netscape

(Complete Reference): http://developer.netscape.com/docs/

manuals/communicator/jsguide4/index.htmQuick Reference from Shelly Cahsman: http://www.scsite.com/js/qr.htmJavaScript Object Reference: http://www.htmlstuff.com/programmer/

jsobjects/index.html

Client-side JavaScript objects

TaskBaca dan pelajari materi Lanjutan +

Contoh, lihat file Javascript2.pptTambahkan pada website Anda:

Show the time and date to a Web page.Add a greeting to a Web page based on

the time of day.Using mouse event handlers create

rollover effect.