Changing Philosophy - E-Commerce - Lecture Slides, Slides of Fundamentals of E-Commerce

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CSCI 3110 Advanced Topics in Web Development

INTRODUCTION TO CLIENT-

SIDE WEB SCRIPTING

Client-Side Scripting

Script embedded in code delivered to browser. Browser executes. Docsity.com

Changing philosophy

Eye candy Google Maps Web 2. Contemporary goal:

Key Client-Side Scripting Concepts

Script delivered to web browser as part of page source code. Browser runs the script. Interpreted language. Browser typically employs "___ script engine" to execute code and control content output and display. Script source code is exposed to the user. Script runs in a "sandbox", restricting some functionality. Docsity.com

Client-side scripting wars

ECMAScript Netscape submitted JavaScript to ECMA in November 1996 as suggested client-side web scripting standard. ECMA-262 adopted July 1997. JavaScript and JScript are both ECMAScript Documentation: http://www.ecmascript.org/docs.php

End of the War (?)

Netscape was browser leader until ~1998. Internet Explorer—"free" (part of O/S). Netscape Navigator – free for non-commercial use. Legacy of Netscape lives on in Mozilla Firefox. although classic JScript still supported in browsers. Docsity.com

Contemporary JavaScript Components

JavaScript

Source: Zakas, N.C., Professional JavaScript for Web Developers. 2nd ed. 2009, Indianapolis, IN: Wiley Pub., p. 3

ECMAScript

Not a complete programming language, but set of foundational syntax, types, keywords, etc. on which a full language can be based. Not strictly Web/browser language. Docsity.com

DOM

Many web designers criticize DOM… "The API of the browser, the Document Object Model (DOM) is quite awful, and JavaScript is unfairly blamed. The DOM would be painful to work with in any language. The DOM is poorly specified and inconsistently implemented… I think writing a Good Parts book about the DOM would be extremely challenging." Crockford, D., JavaScript: The Good Parts. 2008: O'Reilly, p. 3.

Simple DOM Example

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Demo document

Hi there!

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Browser Object Model (BOM)

Browser-specific scripting extensions for element access and manipulation. Not standardized. Examples of BOM functionality: Some areas of common overlap between browser platforms, but mostly divergent.

Summary

The value of client-side scripting and Web 2.0. How we got to where we are today. The technologies that compose the JavaScript language—the de facto standard for contemporary client-side scripting. Docsity.com