University of Phoenix

WEB/238

May 29, 2012

Tanisha D. Jackson

Web Development and the Use of Javascript Creating a Website and presenting it online to users across the world has become a regular occurrence over the past few decades. Web pages belong to companies with services to sell, and others, to individuals with information to share. The basic Web site is built with HTML, and then creatively enhanced with CSS. To create a visually expressive Web site that can attract thousands of visitors each day you need to use more than HTML and decide what the site contains. There are different languages that can be used to add a sense of style to your site, some of the possible devices are JavaScript, Java, DOM, and AJAX. In the following paper our team will discuss a few examples of how each can be used in Web development.

Comparison of Java and JavaScript Java and JavaScript are both object-oriented languages (Burns, 2012). Knowing how to use one language often becomes confusing when attempting to learn the other. Some of the differences between the two are that Java applets can create stand-alone applications that work across platforms running as standalone programs. However, JavaScript cannot create these stand-alone applications and reside on an Internet browser. A programmer must compile Java code before the program can run. This requires an outside program just to compile the code. A compiler turns Java code into machine language code before a browser can interpret it. Any changes the programmer makes to the code will require him to recompile the program and this can be a real tedious act to commit over and over. A web designer can write JavaScript functions directly in a text editor, saving the file and upload it to the server for immediate execution or using an editor like Adobe Dreamweaver that allows for live uploading and being able to see it as you code it. The JavaScript code will compile when a user visits any website. JavaScript extends a web page’s interactive ability by performing tasks not capable in HTML alone. One of JavaScript's main benefits is that it can be understood by an individual and not just a computer. Many JavaScript commands are known as Event Handlers and are often embedded into existing HTML commands (Burns, 2012). JavaScript allows more freedom in the creation of objects while Java is more rigid and requires scripted items to be done without errors. JavaScript organizes and presents data so it can create a variety of functions. These are not stand alone applications like what Java can produce. Even the more versatile JavaScript lacks the capabilities and functions of Java. Java can create applications independent and able to stand alone. This allows Java to be more dynamic and provide more sophisticated and complex applications, while JavaScript is designed to work with HTML to add functionality to a website.

Java, JavaScript, and DOM Java is an object-oriented programming language that can be written in any of the major operating systems like Windows or Linux (About the Java Technology, 2012). Java applications are typically compiled to byte code that can run on any Java Virtual Machine. An example of the appropriate uses of Java is the development of financial applications such as mortgage calculators that can be used to provide information about a user’s mortgage payments over a set period of time. JavaScript is a prototype-based scripting language that is dynamic with first-class functions (About the Java Technology, 2012). It is a multi-dimensional programming language that supports object-oriented, imperative, and functional styles. JavaScript is implemented into most Web browsers to help enhance interfaces and dynamic websites. JavaScript has uses other than for web pages. The Document Object Model or DOM standard is designed for documents. DOM was intended to be language-neutral because it was designed for use with languages such as C and Perl.
JavaScript Scripts

JavaScript is a prototype-based scripting language that is dynamic. In 1995 Netscape spawned a powerful scripting language that was described by many as a simple language (Javascript, 2012). It is impossible to hide JavaScript running in a browser which means anyone can see it, use it, and copy it. There are various scripts available on the Internet that makes a Web site more user- friendly. More than likely there is a script available on-line that can carry out any function you desire. There is a type of Javascript that is used for commercial purposes. For example, a Simple Banner Rotator is a simple JavaScript banner image rotator script. The programmer can set the size and date to be adjusted automatically as well as remove the banner whenever desired. The programmer can write the script to randomly show one banner from the list provided for each ad location on the page. The programmer can also assign specific banners to a location or have them display randomly.

Comparison of AJAX and JavaScript

AJAX is a programming method that uses Asynchronous JavaScript and XML, JAVA is a programming language, and JavaScript is a scripting language. There is a large difference between the three while at the same time they are often hairs on the same horse.

AJAX, (Asynchronous JavaScript and XML), is not a programming language, instead it is a different use of existing elements, not a language as much as a new compilation of older methods that when properly used together, create a valuable tool for software development.

JavaScript is a scripting language, specifically designed to work with HTML pages. JavaScript provides HTML designers a simplified programming tool that can be used to validate data such as form input, create cookies, react to user input, and recognize and respond properly to a user's browser.

The specific comparison of AJAX and JavaScript is that AJAX is designed to streamline the communications between a client and a server, reducing bandwidth and increasing speed. AJAX controls the processing duties by splitting them between the server and the client, thereby making both sides more efficient when sending and processing requests. AJAX makes it possible to update portions of a web page, without the necessity of reloading the entire page. JavaScript is the scripting language that defines the actions that must be completed in each request from a client to a server. Used together they become an effective tool for requesting, processing, and receiving information on the web.

Security Vulnerability of AJAX and JavaScript

Security is a constant concern for developers as well as users of the internet. Any professional web developer will have the issue of security of data and user information right at the top of the list. No matter the looks, feel, or even usability of a website, if it is insecure and dangerous to a website visitor, it is not a successful effort. "Imagine that your computer reaches out across the net, to an unverified site, over an unencrypted link and grabs code that it executes with little in the way of further inspection. There are limits to what JavaScript is allowed to do—meant to thwart malicious uses—but it has to have some privileges on the local machine in order to be useful." Edge 2008. AJAX as well is vulnerable. "There is the general misconception that in AJAX applications are more secure because it is thought that a user cannot access the server-side script without the rendered user interface (the AJAX based webpage). XML HTTP Request based web applications obscure server-side scripts, and this obscurity gives website developers and owners a false sense of security – obscurity is not security. Since XML HTTP requests function by using the same protocol as all else on the web (HTTP), technically speaking, AJAX-based web applications are vulnerable to the same hacking methodologies as ‘normal’ applications." Clearly the security issue relating to JavaScript and AJAX is that they are becoming prevalent in the world of website design and thus are drawing more attention from hackers that want to steal information or disrupt websites for other reasons. As the use of JavaScript and AJAX increases, so will the attempts to attack them.

Summary of the use of Java applets in commercial settings

Applets can add interest to a commercial websites with the use of animations, text effects, graphics and other offerings that can keep a visitor on a site. These effects can be used to highlight product specials, important information, or just to guide visitors through the site and the product purchasing process. Applets can be embedded in a website quickly and easily, allowing a web designer to add special effects and processes to the site without taking the time and effort needed to write the code needed for the process needed. They are a time saver, a great addition to the look and feel of a site, and best of all they are very easy to produce with a little research.

Discussion of the future trend of Java applets in commercial settings

The future of Java applets seems to be in mobile applications. Laptop computers or more limited products like netbooks and tablets can benefit from the simple, easy to execute applet. Even down to smart phones, they have a use. There is also a feeling within the developer community that Java applets are a dead technology and that there is virtually no future for them in the commercial settings, including mobile devices. Other applications are considered as far more effective and better suited for the current commercial market. Flash and Java Webstart have been mentioned as better alternatives.

Comparison of Ajax and Java Applet Ajax is an acronym for Asynchronous JavaScript and XML. Ajax is a combination of related web techniques used on the client-side to create asynchronous web applications. With Ajax, web applications can send data without interfering with the display of an existing page to a server in the background and then retrieve it as well. Ajax is a combination of HTML, JavaScript and CSS, which in turn act like a web browser. With Ajax you can resize window and expect to see text and tables to remain normal. Ajax generally starts faster than an applet and is preloaded by the browser. Unlike JavaScripts Applets doesn’t get loaded when the website launches.
Applets
A Java applet is an applet delivered to users in the form of java byte code. Java applets can run in a Web browser using a Java Virtual Machine. Java applets has a stronger security that Ajax, it is said that unsigned Applets are less dangerous than Ajax. Java applets are simple to run on most popular platforms, which make it cross, platform with may web browser.
Cookies
Cookies are small files, which are stored on a user's computer. It is designed to store a small bit of information to a particular website. Cookies are created when a web browser is loaded or when a submit button is pressed. Cookies are used to transfer information from page to page, this takes some work off the server and also the user doesn’t have to fill out this information again. By default cookies are deleted when the browser is closed unless instructed otherwise. There are lots of concerns about cookies and their similarities to spyware. Cookies do not present a threat to the computer, since there can only retrieve information from the browser.
Spyware
By definition spyware means Advertising Support Software. It is designed to gather information about the user and surfing habits are return info to its source. Some of the more mischievous spyware can collect password, chat logs and just about everything else. This can result in identity thief and stolen information although cookies and spyware may originate from the same source, spyware are harmful for the computer. It can cause slowness to the system, interfere with the user browsing; also it can flood the user’s inbox with advertising emails. Unlike cookies, spyware are difficult to remove because there tend to be more than one when present on a machine
Explanation of the role of JavaScript in DHTML The main use of JavaScript is (Dynamic HyperText Markup Language) DHTML. It is said that DHTML is using JavaScript to modify the CSS styles of HTML elements. DHTML is browser specific, therefore different browsers require a set of instructions to make it function properly. DHTML can achieve its main functions by altering the in-memory documentation of the current document and automatically altering it to show changes. DHTML does not need to reload, create a new, or require another server to generate new content. The process involves just using the persons computer who is accessing it and calculate the necessary data and then carry out.
Conclusion
Understanding JavaScript, Ajax, HTML, Java and other scripts are all part of the skill set needed to pursue a career in web design. To create a website that meets both the customers and the users of the sites expectations requires understanding what goes on behind the scenes in a website. Server side functions, queries to databases, confirmations and sending of information all have to be added as script to the site, pages linked to the site or placed on a server to be referenced link accessed. Creating a website with these exquisite features that has current trends and styles and is competitive with similar sites requires an understanding of script languages that make up a web site. Every script used on a site represents a step in the process of its creation and the combination of functions and features are determined by the scripts placed on its pages. This means a website should not be exclusive or depend too heavily on one in particular. Knowing how to combine different scripts to create the features and functions desired are important skills. Understanding what makes up the features of a website like the scripting languages and software behind the scenes in the process of creating a website. To achieve this requires a basic understanding of the scripting languages and software used in web design.

References

About the Java Technology. (2012). Retrieved from http://docs.oracle.com/javase/tutorial/getStarted/intro/definition.html

Ajax security: Are AJAX applications vulnerable to hack attacks?

Retrieved from http://www.acunetix.com/websitesecurity/ajax.htm

Burns, J. (2012). Java vs. JavaScript: Similarities and Differences. Retrieved from http://www.htmlgoodies.com/beyond/javascript/article.php/3470971/JavavsJavaScript .htm

Introduction to Dynamic HTML Retrieved from http://msdn.microsoft.com/en-us/library/ms533044(v=vs.85).aspx

Javascript. (2012). Retrieved from http://www.w3schools.com/js/js_intro.asp

Web security vulnerabilities and JavaScript, Jake Edge, 2008.

Retrieved from http://lwn.net/Articles/266303/