2. IntroductionIntroduction
Web developers view web pages as
documents that must be created according to
authoring and development guidelines
Web developers use HTML or XHTML to
write code of a web page
Web browsers have a built-in interpreter to
render the results of the code in its window
3. The World Wide WebThe World Wide Web
Definitions
HTML
The HyperText Markup Language
The language used to structure text-based information
in a document
by denoting certain text as headings, paragraphs, lists,
etc — and to supplement that text with interactive forms,
embedded images, and other multimedia objects
XHTML
The eXtensible HyperText Markup Language
XHTML consists of all the elements in HTML 4.01
combined with the syntax of XML.
Allows users to define their own “tags” for defining
structure, layout, etc.
4. Content of Web PagesContent of Web Pages
A web site may contain a combination of 13
standard elements:
Text Sound
Lists Video
Hyperlinks Tables
Colour Layers
Graphics Frames
Images Forms
Image Maps
5. Content of Web PagesContent of Web Pages
The content of a web site can be classified
as:
Static content – does not change regularly e.g.
personal and professional web sites
Dynamic content – changes regularly e.g.,
newspaper web sites, weather report sites…
6. Authoring of Web PagesAuthoring of Web Pages
After a web page layout is designed, one needs to use
HTML/XHTML code to implement the design
Introduction to XHTML
Syntax
Document Tags
Authoring tools
Text formatting
Special characters
Hyperlinks
Lists
Meta Data
Colours
Audio & Video
7. XHTML SyntaxXHTML Syntax
XHTML uses tags that are enclosed in brackets < >
XHTML content is contained between tags
Tags and content form an XHTML element
Generic element form: <start-tag> content <end-tag>
Start and end tags have the same name, end tag has a
‘/’ before it: <b>This is BOLD</b>
XHTML tags can be nested according to the “first open,
last closed” rule: <b><i>bold and italic</i></b>
8. XHTML SyntaxXHTML Syntax
XHTML rules
Tags must be closed
XHTML is case sensitive
Use lower case tags and attribute names, e.g. width=“100%”
All attribute values must be double quoted, e.g. “100%”
Tags must not overlap (i.e., during nesting)
Comments can be used
<!-- This text is a comment -->
Do not use obsolete (deprecated) tags
Browsers ignore misspelled tags (and many other things!)
9. Document TagsDocument Tags
The tags that make up the framework of a typical XHTML document
include the following:
Document type definition (DTD) tag – DOCTYPE
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
Describes (to web browsers) what type/version of (x)html is used
Specifies rules that apply to the markup of documents
Used for document syntax validation (e.g. strict) and for web browser to
process document in proper “parsing” mode (impacts on consistency
and speed of display)
An XHTML document is validated against a Document Type Definition.
Top-level tag, generally <html>
Tag indicates the beginning and /end of an XHTML document
12. HTML Document StructureHTML Document Structure
<html>
<head>
<title>HTML Document Structure</title>
<meta name=“author” content=“Andrea Curley” />
</head>
<body>
all web page content goes here
</body>
</html>
13. Document Tags - HeaderDocument Tags - Header
Header section, delimited by <head> tags
Provides extra information about the document
Serves as a container for styles, global scripts, etc.
The main tags used in this section are:
<title> - specifies the document title
<meta> - provides information to search engines
<style> - declares general & local styles for the document
<script> - declares any scripting information
14. Meta TagsMeta Tags
Web pages are designed for surfers and surf engines
The <meta> tag increases the chances of page indexing
Meta data refers to data about XHTML document rather
than the document content
Browsers do not render meta data
Search engines use it for indexing and ranking the page
hits in a given search
Some attributes of this tag are name, content, http-equiv,
etc.
15. Meta TagsMeta Tags
Most often the meta element is used to provide information
that is relevant to browsers or search engines like
describing the content of your document.
<meta name=“keywords” content=“open, source, PHP,
programming, code” />
When a search engine indexes the page, it includes the
extra information -> open, source, etc.
It provides these keywords to search agents requesting
them
16. Amazon’s Meta TagsAmazon’s Meta Tags
<meta name="description" content="Low prices on digital cameras,
MP3, LCD TVs, books, music, DVDs, video games, software, home &
garden and much, much more. Free delivery on orders over £15." />
<meta name="keywords" content="digital camera, LCD TV, books, DVD,
low prices, video games, pc games, software, electronics, home,
garden, video, amazon" />
17. Document Tags - BodyDocument Tags - Body
Body section, delimited by <body> tags
Section where visible content appears
Content is a series of block tags containing inline
content
18. How can I write my first web page?How can I write my first web page?
1. Open a text editor e.g., Notepad, Edit Plus
2. Put in code from the HTML Document Structure
Slide
3. Save it as Example1.html
4. In web browser (IE/Firefox/Netscape),
Select File -> Open
Select Example1.html
Select OK
19. Authoring ToolsAuthoring Tools
Tools needed to develop a web site:
Editor
Graphics program
Digital cameras
Scanners
Audio & video software
Types of editors
Text: type in code and view results later -> Bottom-up development
HTML: view results as you develop the web page -> top-down
development
Web author must be familiar with both approaches
e.g. “EditPlus”, “MacroMedia Dreamweaver”
21. ParagraphsParagraphs
Main textual blocks, delimited by <p> tags
<p>This is a paragraph of text in an XHTML document</p>
This is a paragraph of text in an XHTML document
Line spacesLine spaces
automaticallyautomatically
insertedinserted
22. Line breaksLine breaks
Used when you need to break a line prematurely
(before the paragraph)
The line break tag is <br />
Need space between “br” and “/” for Netscape
browsers to interpret correctly
23. Lines - ExampleLines - Example
<p>This is a paragraph of text in an XHTML document</p>
<p>This is a 2nd paragraph of text in an XHTML document</p>
This is a paragraph of text in an XHTML document
This is a 2nd paragraph of text in an XHTML document
<p>This is a paragraph of text in an XHTML document</p>
<p>This is a 2nd paragraph of text <br /> in an XHTML document</p>
This is a paragraph of text in an XHTML document
This is a 2nd paragraph of text
in an XHTML document
24. HeadingsHeadings
There are 6 levels of headings <h1>…..<h6>, the higher
the heading number the smaller the text
<h1> Heading 1</h1>
<h2> Heading 2</h2>
<h3> Heading 3</h3>
<h4> Heading 4</h4>
<h5> Heading 5</h5>
<h6> Heading 6</h6>
Heading 1Heading 1
Heading 2Heading 2
Heading 3Heading 3
Heading 4Heading 4
Heading 5Heading 5
Heading 6Heading 6
25. Horizontal RulesHorizontal Rules
Horizontal rules appear as lines across the browser screen
- <hr /> use space between “hr” and “/” so Netscape
browsers can interpret correctly
Used to separate information visually
A line should be drawn under this text <hr />
A line should be drawn under this text
26. Block Divisions (div)Block Divisions (div)
Sometimes, there is a need to format a large block of text
in a similar fashion but in a way that is different from other
blocks in the same document e.g. a quoted block of text
could appear in a different style than the text around it -
<div>
<div align="center">
Text formatted using div tag
</div>
Text formatted using div tag
27. Text FormattingText Formatting
TextText
HeadingsHeadings ParagraphsParagraphs Word/CharactersWord/Characters
<h1> largest<h1> largest
..
..
<h6> smallest<h6> smallest
<p><p>
<b> bold<b> bold
<i> italic<i> italic
<br /> line break<br /> line break
<div> acts like a line break<div> acts like a line break
<hr /> line in a web page,<hr /> line in a web page,
28. HyperlinksHyperlinks
Hyperlinks <a> link web pages to each other
A link is a connection from one source to another
Hyperlinks create hypertext and is the driving force of the web
Hyperlinks can be used as:
inter-document and intra-document links
Links start at the source (visible part) and points to the
destination (invisible part)
<a href="http://www.w3schools.com/"> Visit W3Schools! </a>
address of theaddress of the
document to link todocument to link to
(invisible)(invisible)
Text to beText to be be displayed as a hyperlinkbe displayed as a hyperlink
(visible)(visible)
29. HyperlinksHyperlinks
The important attributes of the link <a> tag:
href
title
name
charset
type
rel
rev
accesskey
shape
coords
30. HyperlinksHyperlinks
The visible part of the link may have 4 states
Link – is not active and has not been visited
Active – target of the link is active in another browser window
Visited – target of the link has been previously visited
Hover – mouse pointer is over the link
Redirect Example
<html>
<head>
<meta http-equiv="Refresh" content="5;url=http://www.dit.ie" />
</head>
<body>
<p>Sorry! We have moved! The new URL is: <a
href="http://www.dit.ie">www.dit.ie</a></p>
<p>You will be redirected to the new address in five seconds.</p>
<p>If you see this message for more than 5 seconds, please click on the link above!</p>
</body>
</html>
31. Hyperlinks - anchorsHyperlinks - anchors
for “external” link
<a href=http://www.dit.ie target=“_blank”> This is the DIT web
site</a>
…for “internal” link
<a href=“#Section1”> jump to Section 1</a>
.
<a name=“Section1”>Section 1</a>
… for “mail to” link
<a href="mailto:someone@dit.ie">email someone@dit.ie</a>
32. ListsLists
XHTML supports 3 types of lists:
Ordered – <ol>
Unordered – <ul>
Definition – <dl>
Lists may be nested to obtain multiple hierarchy
levels
33. Ordered List - <ol>Ordered List - <ol>
Lists whose elements must appear in a certain
order
Such lists usually have their items prefixed with a
number or letter
<ol><ol>
<li>Apples</li><li>Apples</li>
<li>Bananas</li><li>Bananas</li>
<li>Coconuts</li><li>Coconuts</li>
</ol></ol>
1.1. ApplesApples
2.2. BananasBananas
3.3. CoconutsCoconuts
34. Ordered List - <ol>Ordered List - <ol>
How can the numbering style be changed??
Some other style options:
decimal
lower-roman
upper-roman
upper-alpha
<ol<ol style=“list-style-type: lower-alpha”style=“list-style-type: lower-alpha”>>
<li>Apples</li><li>Apples</li>
<li>Bananas</li><li>Bananas</li>
<li>Coconuts</li><li>Coconuts</li>
</ol></ol>
a.a. ApplesApples
b.b. BananasBananas
c.c. CoconutsCoconuts
35. Unordered List - <ul>Unordered List - <ul>
Lists whose elements do not have to appear in a
numbered order
<ul><ul>
<li>Apples</li><li>Apples</li>
<li>Bananas</li><li>Bananas</li>
<li>Coconuts</li><li>Coconuts</li>
</ul></ul>
• ApplesApples
• BananasBananas
• CoconutsCoconuts
36. Unordered List - <ul>Unordered List - <ul>
How can the list item marker be changed??
Some other style options:
disc
circle
none
<ul<ul style=“list-style-type: square”style=“list-style-type: square”>>
<li>Apples</li><li>Apples</li>
<li>Bananas</li><li>Bananas</li>
<li>Coconuts</li><li>Coconuts</li>
</ul></ul>
ApplesApples
BananasBananas
CoconutsCoconuts
37. Definition List - <dl>Definition List - <dl>
More complex than the other 2 lists due to their
having 2 elements per list item
<dl><dl>
<dt>Internet Explorer</dt><dt>Internet Explorer</dt>
<dd>Developed by Microsoft</dd><dd>Developed by Microsoft</dd>
<dt>Netscape</dt><dt>Netscape</dt>
<dd>Developed by Netscape</dd><dd>Developed by Netscape</dd>
</dl></dl>
Internet ExplorerInternet Explorer
Developed by MicrosoftDeveloped by Microsoft
NetscapeNetscape
Developed by NetscapeDeveloped by Netscape
38. Nesting ListsNesting Lists
Lists can be nested of the same or different types
<ul><ul>
<li>Send us a letter, including:</li><li>Send us a letter, including:</li>
<ol><ol>
<li>Your full name</li><li>Your full name</li>
<li>Your order number</li><li>Your order number</li>
<li>Your contact information</li><li>Your contact information</li>
</ol></ol>
<li> Use the web form to send an email </li><li> Use the web form to send an email </li>
</ul></ul>
• Send us a letter, including:Send us a letter, including:
1.1. Your full nameYour full name
2.2. Your order numberYour order number
3.3. You contact informationYou contact information
• Use the web form to send an emailUse the web form to send an email
39. ColoursColours
Colour is an essential element and greatly improves
visualisation
A web author can set colours for background and text
Tags have a color attribute that enables web authors to set
colours for different XHTML elements
Colours can be specified using hexadecimal codes for
multi-browser consistency
Black -> #000000
Red -> #FF0000
Blue -> #0000FF
Colours can be set globally or locally
40. Audio & VideoAudio & Video
XHTML allows authors to incorporate digital audio and
videos in a web page
Audio formats – AU, WAV, MIDI, AIFF and MP3
Video formats – AVI, QuickTime, MPEG and MJPEG
A surfer must have the right hardware and software to be
able to play multimedia content of the web page
<embed> tag causes a control panel to be displayed for
audio and video files in a web page
Attributes used are src, width and height, volume,
autostart, loop and hidden
42. ReferenceReference
Steven M. Schafer (2005), HTML, CSS, JavaScript, Perl, and PHP
Programmer's Reference, Hungry Minds Inc,U.S.
Dan Cederholm (2005), Bulletproof Web Design: Improving Flexibility
and Protecting Against Worst-Case Scenarios with XHTML and CSS,
New Riders.
Ibrahim Zeid (2004), Mastering the Internet, XHTML, and Javascript
