Prayagasoft - web designer India, Ecommerce developer india, Ecommerce design

Client Side Technologies

Client side technologies are those that are interpreted (executed) by the user's browser. So basically when you type a website's address in your web browser, the latter will make a request to the web server where your HTML files are stored, and the HTML file is send to the browser for viewing. The different technologies that are included in the HTML page like CSS, JavaScript, are all executed on the client browser. A limitation of client-side programming is that it is hard to tell what browser/platform your users are using, and it might turn out that some of the client-side technologies are not supported (or not fully supported) by the browser, thus your web page might be incorrectly displayed. The section that follows will take you on a quick tour to discover the major client-side technologies.

CSS (Cascading Style Sheets)

To understand the CSS, its worth recalling back the main purpose of HTML. The latter was originally designed as a structural language, but with time and updates, HTML has been used as a tool for presentation, making use of fonts, colors and other visual elements. The purpose of CSS is now to restore HTML to its original structural language. In other words, cascading style sheets are a new way of formatting your page layout, text, fonts, images, and almost anything that controls the look and feel of your web page. It is included either in-line with the HTML file or linked as a separate file which can then be used by different HTML files. The advantage of separating the structure and look is that web pages can be tailored for different users, browsers, and platform and an obvious benefit is that updating becomes easier.

Let's take a quick example at a usage of CSS. Suppose you want all your <H1> tags to have a 10-point Verdana font. Instead of defining every all your <H1> tags in your page with these preferences, you can just use the CSS:

H1 {font-family: Verdana; font-size: 10pt;)

But CSS usage goes far beyond that. CSS is capable of spacing out the content of a page down to the very last pixel...it can do the same when sizing text, thus giving you complete control over the look and feel of your page. In fact CSS will replace some older HTML tags in future browser versions.

JavaScript

JavaScript is a scripting language developed by Netscape and supported as Jscript in Microsoft Internet Explorer. The language was turned to ECMAScript, as a cross-platform Internet standard for scripting. But we still use the most commonly recognised JavaScript name. JavaScript should not be confused with Java. Despite similarities in their names, these 2 languages are completely different from each other.

JavaScript is a core web technology that every designer is encouraged to understand well. It was born out of desire to let HTML authors write scripts directly in their documents. JavaScript brings programming power within the reach of everyone familiar with HTML.

JavaScript borrows its syntax from C/C++ and those familiar with C will feel right at home. But those without any programming experience will find that JavaScript is not the easiest language in the world to learn but it's a far cry from having to learn a full programming language such as Java or C.

JavaScript is interpreted on the client-side (on the user's browser), and is shipped in every platform-specific version of Netscape Navigator 2 and Internet Explorer 4. It can be used to enhance web page in many ways, for example, validating form, adding user interactivity, process data or control multiple frames. It handles events for the various HTML elements, for example, it allows buttons to have OnClick event handlers. While most people find use of JavaScript to client-side only, JavaScript can also be used in servers, authoring tools.

VBScript

Microsoft's Visual Basic Script (VBScript) offers the functions of a programming language and the simplicity of a technology streamlined for the Web. With VBScript, you can bring your Web pages to life with real-time interaction; there's no more waiting for a server to respond to button clicks and mouse movements. A click of a button gets an instant reaction, and the movement of the mouse over an object brings the object to life.

When you enhance your Web pages with VBScript, you insert scripts directly into your pages. Because VBScript is a subset of Microsoft's Visual Basic, your scripts resemble programs written in Visual Basic. If you aren't a programmer, don't worry. The wonderful thing about VBScript is that it's a very simple programming language to learn and to use. Many Web publishers who aren't programmers use VBScript to enhance their Web pages.

Like most basic programming languages, VBScript is an interpreted language, which is both good news and bad news. The good news is that you don't need to compile your scripts as you would with a program written in C or C++. Your scripts are directly interpreted, line-by-line, when they're executed in the user's browser. The bad news is that before anyone can run your scripts, he or she needs a VBScript interpreter, which is part of the standard Internet Explorer browser package. It's installed automatically when you install Internet Explorer

DHTML

DHTML, or Dynamic HyperText Markup Language is a collection of coding languages like HTML, CSS, JavaScript. It allows a web site developer to build dynamic abilities into what would normally be a static web page. What this means is that a web page may be changed after it has been loaded using DHTML. This provides a basis for many useful capabilities, and can make web pages interactive, or feel more alive. The major browsers that support DHTML are the fourth and fifth generation versions of Microsoft Internet Explorer and Netscape Navigator .

Java

Java was developed by Sun Microsystems and is a programming language with complete functionality like that of C++. At this point, Java's niche is on the World Wide Web. Probably the most important things that Java brings to the Web are the capacity for more interactivity on the Internet through multimedia and animation. Most modern browsers have support for Java.

Java applets are a hybrid form of Java programs to run on a Java-compliant browser on the World Wide Web. An applet is one or more .class files which together form a program. Unlike other types of program, applets are designed to be run from within a web (HTML) page. In this way, they differ from scripts such JavaScript which are text commands typed into the HTML page itself. Some common use of Java applets include image slideshows, chat rooms etc.

Flash & ActionScript

Macromedia Flash is an authoring tool that can create a special type of file called "Flash movie" and has ".swf" as extension. You can see this type of movie more and more in common pages on the Internet, and sometimes you don't even recognize it as Flash movie because it looks like a normal animated banner. Flash supports animation and sound. If you have created your graphics in Flash, you will be able to move these on the "stage". As in a real film, you put your graphics on the stage and tell the program if and when they should move. You have a "timeline" where you do control the timing of the animation, and you have "keyframes" where you do control the position of the objects on the stage. ? Flash contains a powerful programming language called "ActionScript" that is capable of doing much more. With ActionScript you can build movies which can interact with the viewer. This will be very convenient, if you want to build a quiz, a game or a shopping cart in Flash. If you can use an additional script language on your web server, you are even able to build complex database applications on the Web .