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© Keith Vander Linden, 2005
The applications of science have built man a well-supplied house, and are teaching him to live healthily therein. They have enabled him to throw masses of people against one another with cruel weapons. They may yet allow him truly to encompass the great record and to grow in the wisdom of race experience.
- V. Bush, Atlantic Monthly, 1945
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© Keith Vander Linden, 2005
Presenting Information
● HTML (http://www.w3schools.com/html/)(Chapter 2)
● XML (http://www.w3schools.com/xml/)
● World-Wide Web (http://www.w3.org)
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© Keith Vander Linden, 2005
Hypertext Markup Language
● A document formatting language that supports:– Formatted text– Images– Hyperlinks to other documents
● Working with HTML documents:– Web browsers display HTML documents– Editors create/modify HTML documents
● HTML marks up a document’s text using tags.
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© Keith Vander Linden, 2005
An Example
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© Keith Vander Linden, 2005
HTML Document Structure
<!DOCTYPE Document_Type_Specification> <html> <head> <title>Title_Bar_Text</title> </head> <body> Web_Page_Elements </body> </html>
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© Keith Vander Linden, 2005
HTML Tags – Title bar
<head> <title>Acme Traders</title> </head>
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© Keith Vander Linden, 2005
HTML Tags – Text Formatting
<h1 align="center">Acme Traders</h1>
<b>Grand Rapids, Michigan, USA</b>
<i>Phone: 1-800-555-5555</i>
<h2>Customer Service</h2>
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© Keith Vander Linden, 2005
HTML Tags – Lists
<ul> <li>How to Order</li> <ol> <li>Select Items</li> <li>View Your Shopping Cart</li> <li>Check Out</li> </ol> <li>Shipping and Returns</li> <li>Check on Your Order</li></ul>
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© Keith Vander Linden, 2005
HTML Tags – Images
<img src=“images/acme_septimus_t.gif" height="200" width="200“ />
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© Keith Vander Linden, 2005
HTML Tags – Other graphics
<hr size="5" noshade>
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© Keith Vander Linden, 2005
HTML Tags – Hyper Links
<a href="planner.htm"> <h2>Planner</h2> </a>
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© Keith Vander Linden, 2005
HTML Special Characters
<small>©acme.org (7/4/03)</small>
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© Keith Vander Linden, 2005
HTML Comments
<!-- Company logo/horizontal rule -->
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© Keith Vander Linden, 2005
HTML Tags – Tables
<table align="center" border="5" cellspacing="3" cellpadding="5"> <tr> <th>Item Number</th> <th align="left">Description</th> <th>Image</th> </tr> <tr> <td align="center" valign="top">1</td> <td valign="top">Magnet</td> <td><img src=“images/magnet.jpg"></td> </tr> <tr> <td align="center" valign="top">2</td> <td valign="top">Umbrella</td> <td><img src=“images/umbrella.gif"></td> </tr></table>
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© Keith Vander Linden, 2005
XML
● Extensible Markup Language● An extendable generalization of
HTML ● You define your own tags using a
document type definition (DTD)● Is fast becoming a standard
information interchange format.
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© Keith Vander Linden, 2005
An Example
<?xml version="1.0" encoding="ISO-8859-1"?> <!DOCTYPE note SYSTEM "InternalNote.dtd"> <note> <to>Class</to> <from>Keith</from> <heading>Reminder</heading> <body>Don't forget project 6!</body> </note>
<?xml version="1.0"?> <!ELEMENT note (to,from,heading,body)> <!ELEMENT to (#PCDATA)> <!ELEMENT from (#PCDATA)> <!ELEMENT heading (#PCDATA)> <!ELEMENT body (#PCDATA)>
Document type definition:
XML data file:
Example from www.w3schools.com July, 2003
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© Keith Vander Linden, 2005
Tim Berners-Lee (1955- ) World Wide Web
● late 1980’s● Developed the key elements of
the WWW:– URL - universal resource locators– HTTP - hypertext transfer protocol– HTML - hypertext markup language
● Provided the basis for an implementation of Vannevar Bush’s vision of the memex.
Image from www.adlandia.dk July, 2003
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© Keith Vander Linden, 2005
How Big is the WWW?
● Who really knows?– “surface” web - ~50 terabytes– “deep” web - ~7500 terabytes
● Key challenges for the 21st century:– Mining– Filtering
What’s theBig Idea