Site Building Introduction

From http://www.w3schools.com (Copyright Refsnes Data)

# Web Building

Every Web developer has to know the building blocks of the Web:

- HTML 4.01
- The use of CSS (style sheets)
- XHTML
- XML and XSLT
- Client side scripting
- Server side scripting
- Managing data with SQL
- The future of the Web

## HTML 4.01

HTML is the language of the Web, and every Web developer should have a basic understanding of it.

HTML 4.01 is an important Web standard. and very different from HTML 3.2.

When tags like <font> and color attributes were added to HTML 3.2, it started a developer's nightmare. Development of web sites where font information must be added to every single Web page is a long and expensive pain.

With HTML 4.01 all formatting can be moved out of the HTML document and into a separate style sheet.

HTML 4.01 is also important because XHTML 1.0 (the latest HTML standard) is HTML 4.01 "reformulated" as an XML application. Using HTML 4.01 in your pages makes the future upgrade from HTML to XHTML a very simple process.

Make sure you use the latest HTML 4.01 standard.

Study our Complete HTML 4.01 reference.

## Cascading Style Sheets (CSS)

Styles define how HTML elements are displayed, just like the font tag in HTML 3.2. Styles are normally saved in files external to HTML documents. External style sheets enable you to change the appearance and layout of all the pages in your Web, just by editing a single CSS document. If you have ever tried changing something like the font or color of all the headings in all your Web pages, you will understand how CSS can save you a lot of work.

Make sure you study our CSS tutorial.

## XHTML - The Future of HTML

XHTML stands for Extensible HyperText Markup Language.

XHTML 1.0 is now the latest HTML standard from W3C. It became an official Recommendation January 26, 2000. A W3C Recommendation means that the specification is stable and that the specification is now a Web standard.

XHTML is a reformulation of HTML 4.01 in XML and can be put to immediate use with existing browsers by following a few simple guidelines.

To prepare for the future: Read how this site was converted to XHTML.

## XML - A Tool for Describing Data

The Extensible Markup Language (XML) is NOT a replacement for HTML. In future Web development, XML will be used to describe and carry the data, while HTML will be used to display the data.

Our best description of XML is as a cross-platform, software- and hardware-independent tool for storing and transmitting information.

We believe that XML is as important to the Web as HTML was to the foundation of the Web and that XML will be the most common tool for all data manipulation and data transmission.

Make sure you study our XML tutorial.

## XSLT - A Tool for Transforming Data

XSLT (Extensible Stylesheet Language Transformations) is a language for transforming XML.

Future Web sites will have to deliver data in different formats, to different browsers, and to other Web servers. To transform XML data into different formats, XSLT is the new W3C standard.

XSLT can transform an XML file into a format that is recognizable to a browser. One such format is HTML. Another format is WML - the mark-up language used in many handheld devices.

XSLT can also add elements, remove, rearrange and sort elements, test and make decisions about which elements to display, and a lot more.

Make sure you study our XSLT tutorial.

## Client-Side Scripting

Client-side scripting is about "programming" the behavior of an Internet browser. To be able to deliver more dynamic web site content, you should teach yourself JavaScript:

- JavaScript gives HTML designers a programming tool - HTML authors are normally not programmers, but JavaScript is a scripting language with a very simple syntax! Almost anyone can put small "snippets" of code into their HTML pages.
- JavaScript can put dynamic text into an HTML page - A JavaScript statement like this: document.write("<h1>" + name + "</h1>") can write a variable text into an HTML page.
- JavaScript can react to events - A JavaScript can be set to execute when something happens, like when a page has finished loading or when a user clicks on an HTML element.
- JavaScript can read and write HTML elements - A JavaScript can read and change the content of an HTML element.
- JavaScript can be used to validate data - A JavaScript can be used to validate form data before it is submitted to a server, this will save the server from extra processing.

Make sure you study our JavaScript Tutorial.

## Server-Side Scripting

Server-side scripting is about "programming" an Internet server. To be able to deliver more dynamic web site content, you should teach yourself server-side scripting. With server-side scripting, you can:

- Dynamically edit, change, or add any content of a Web page
- Respond to user queries or data submitted from HTML forms
- Access any data or databases and return the results to a browser
- Access any files or XML data and return the results to a browser
- Transform XML data to HTML data and return the results to a browser
- Customize a Web page to make it more useful for individual users
- Provide security and access control to different Web pages
- Tailor your output to different types of browsers
- Minimize the network traffic

At W3Schools we demonstrate server-side scripting by using Active Server Pages (ASP) and PHP: Hypertext Preprocessor (PHP).

Make sure you study our ASP tutorial or our PHP tutorial.

## Managing Data with SQL

The Structured Query Language (SQL) is the common standard for accessing databases such as SQL Server, Oracle, Sybase, and Access.

Knowledge of SQL is invaluable for anyone wanting to store or retrieve data from a database.

Any webmaster should know that SQL is the true engine for interacting with databases on the Web.

Make sure you study our SQL tutorial.

## What Will the Future Bring?

One important thing to know is that the functionality of Web Sites will change very drastically. We will see a huge shift from sites displaying "static content" to data driven sites delivering "dynamic content".

We will also see a lot of new browsers, like the browsers found in mobile devices, and we will see a lot more use of XML to communicate data between servers, and between servers and browsers.

From http://www.w3schools.com (Copyright Refsnes Data)