Source Hobbes' Internet Timeline
Hypertext Transfer Protocol
HTTP consists of two phases - the request and response.
Each communication between a browser and a Web server consists of two parts, a header and a body.
The header contains information about the communication
The body contains the data of the communication if any
Request:
HTTP-Method Resource HTTP/version Header fields <Blank line> Message
For example:
GET /storefront.html HTTP/1.1 Accept: text/*
Response:
Status line Response header fields <Blank line> Response body
For example:
HTTP/1.1 200 OK <html> ...etc...
GET -- return the contents of some resource
HEAD -- return just the header information for a resource
POST -- Submit data to a resource or program
PUT -- create a new resource or replace an existing one
DELETE -- delete a resource
A URL is a name for a resource which contains information about how to acquire the resource.
<scheme>:<scheme-specific-part>
For the HTTP scheme:
http://<net_loc>/<path>;<params>?<query>#<fragment>
Examples:
http://www.comp.mq.edu.au/units/comp249/assignments.html http://www.comp.mq.edu.au/units/comp249/cgi-bin/echo.py?name=steve http://www.comp.mq.edu.au/units/comp249/assignments.html#assesment ftp://box.comp.mq.edu.au/pub/incoming/uploaded.zip nntp://news.mq.edu.au/comp.lang.tcl/ax7529s82008
Reference: Cool URIs don't change.
Hypertext: documents which link to other documents and multimedia resources
Markup: HTML adds information to text to encode function, appearance and behaviour. It's an example of a markup language like XML, SGML, LaTeX and RTF.
Not all documents on the Web are HTML documents. HTTP can be used to transmit images, video: any kind of electronic data.
Versions of HTML:
HTML 4.01
XHTML 1.0
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" >
<html>
<head>
<title>COMP249 Basic HTML Page Structure</title>
</head>
<body>
<h1>COMP249 Basic HTML Page Structure</h1>
<p>This is a paragraph, you know what a paragraph is don't you?</p>
<h2>Some Detail</h2>
<p>This document contains a header which was encoded in the HTML
source using the <h1> tag. Note how I wrote that in the
source, it's an example of the need for <em>entities</em> in
HTML.</p>
<hr />
<p>Copyright © Steve Cassidy, 2004 </p>
</body>
</html>
What is a browser?
How many browsers have you used?
Are all browsers equal?
Browser News shows some browser statistics.
Visual Design
User Interface Design
Information Architecture
From Jakob Nielsen's guidelines for good Home Page design:
Make the Site's Purpose Clear: Explain Who You Are and What You Do
Help Users Find What They Need
Reveal Site Content
Use Visual Design to Enhance, not Define, Interaction Design
Site Navigation
Clear and consistent navigation structure
'Two Clicks' rule
Provide a search facility
Response times
Large/many graphics slow down page loading
Complex server side processing can be slow
0.1 second is instantaneous, 1 second is quick, 10 seconds should be the limit.
Hypertext Links
Should be short descriptive phrases
Avoid Click Here links.
Images
Use images optimised for web delivery: compressed, reduced colour palette.
Use thumbnails which link to larger images where possible.
Re-use images for page design.