Language used to define web pages. What the server sends to the browser. Browser reads HTML and renders the page May require downloading data from server (e.g., images)1• HTML - HyperText Markup Language• HTML Standard • Developed by the World Wide Web Consortium (W3C)• http://www.w3.org• Document is described through a series of commands and directives present in a text file.• HTML goal is to describe structure only. Presentation should be left to cascading style sheets.• When interpreted by an HTML viewer those commands determine the appearance of the page• HTML documents are entirely ASCII text .• Commands are explicitly inserted .• Great HTML/CSS tutorial site:• http://www.htmldog.com/2 Three versions of HTML HMTL 4.01 Strict (excludes deprecated tags and attributes). HTML 4.01 Transitional (less restrictive including appearance elements). HTML 4.01 Frameset (identical to transitional but allows <body> to be replaced with <frameset>). Web Standards Project (www.webstandards.org) Industry watchdog convincing web browsers developers to adhere to web standards. HTML 4.01 is the last version for HTML. Next version is XHTML 1.0 XHTML Uses same tags as HTML 4.01. Enforces rules like closing tags, tags in lowercase, and others. We will be using XHTML (strict). HTML Validation - http://validator.w3.org/3• An html document has two main parts.• Header – provides information about the document.• Body – contents of the page.• Example 1 (BasicFrame.html)<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN""http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"><html xmlns="http://www.w3.org/1999/xhtml" lang="en" xml:lang="en"><head><meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1" /><title>Template</title></head><body><!--HTML CODE HERE--></body></html>• Let’s validate the above document4• Tag • Specifies a command or directive. • It surrounds content and apply meaning to that content• General format:<elementName attributes>• Most HTML elements have two tags:• Start tag and end tag• Example: <h1> text </h1>• Tags and attributes will be in lowercase (XHTML requirement).• Some tags are self-closed (ending them in />)<hr /> <br /> <meta /> <img />5 <head> </head>• It does not generate displayed contents.• Contains other tags (e.g., <title> </title>) <title> </title>• Part of the header.• It is required.• Search engines depend on it.6• An attribute extends or modifies a tag.• Attributes • Only appear in the start tag.• You can have several attributes in one tag each separated by spaces.• Order is immaterial.• Some take values which are specified after an =• General format• <ELEM ATTR=“attrValue”>Displayed Text</ELEM>• Example• <img src="bear.gif" width="100" height="75" alt="bear image" />• All attribute values will be enclosed in “ “ for XHTML
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