cos 125
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COS 125. DAY 5. Agenda. Questions from last Class?? Assignment #1 Graded 16 A’s, I non-submit Too Easy! Assignment #2 will be posted by next class Quiz #1 on Feb 3, 20 M/C, 4 Short essays, One extra Credit Chap 1-28 Today’s Topic Finish on Communicating on the Internet - PowerPoint PPT PresentationTRANSCRIPT
COS 125
DAY 5
Agenda
Questions from last Class?? Assignment #1 Graded
16 A’s, I non-submit Too Easy!
Assignment #2 will be posted by next class Quiz #1 on Feb 3,
20 M/C, 4 Short essays, One extra Credit Chap 1-28
Today’s Topic Finish on Communicating on the Internet Start on Using the World Wide Web
How Internet Chat works
Live keyboard conversation on the Internet Most popular is Internet Relay Chat
Topic are channels (Chat Rooms) Chat works on Client/Server model
Users are on clients The chat room is on a server
There are many proprietary Chat solutions WebCT
How IRC works
Images from http://www.nur.ac.rw/chat.htm
Chat stuff
Acronyms brb = be right back
bbl = be back later btw = by the way np = no problem lol = laughing out loud re = hi again, as in 're hi' rotfl = rolling on the floor laughing bbiaf = be back in a flash ttfn = ta ta for now imho = in my humble opinion j/k = just kidding wb = welcome back
Emoticons :) Smile :-) Basic Smile ;-) eye wink :-( sad :-I Indifference :-> Sarcastic >:-> Diabolic (-: left handed %-) Drunk 8-) Uses glasses B:-) Sunglasses on head B-) dark sunglasses 8:-) little girl :-{) Mustache :-{}painted mouth {:-)with hair :-^) with flu :-)^ choking :'-( crying :-@ shouting :-& cant talk -:-) punk
|:-) fall sleep :-O waking up 0:-) angel :-D laughing :-X lips seal :-Q smoker :-/ skeptic C=:-) chef @= nuclear bomb *:O) clown [:-) using walkman (:I egghead @:-) with turban X-( just died :] friendly smile :D laugh :( again sad :O shouting [] hugs :* kisses :*, ;* more kisses :*, :*, :*, :*, more and more kisses
Instant Messaging
Differs from chat in that it is one-to-oneChat one-to-many
Four popular software applications that have little to no interoperabilityMSN Messenger®
AOL Instant Messenger® ICQ®
YAHOO! Messenger®
How Instant Messaging works
Login to messaging server (AOL, MSN)Send your buddy list to server
Server tells you which of your buddies are logged in
Select on inline buddy to talk toSome systems connect buddy to buddy to
chat (MSN)Other run all chats through the server (AIM)
How Internet Phone Calls Work
This is using the Internet to replace the Public Switched Telephone systemSave money on long distanceCalled Voice over IP or VoIP
Converts Voice (analog) to digital packets and vise versaDigital packets sent over the internet
PC Phones
PC to PC
PC to Regular Phone
Regular Phone to Regular Phone
Images from http://www.pc-telephone.com/
PBX-PBX IP Telephony
OrdinaryTelephone
OrdinaryTelephone
Frame Relay, ATM, orthe Internet
IPPacket
PBX withIP Telephony Module
PBX withIP Telephony Module
IP Phones from Cisco
How Web Pages Work
Pages “live” on the World Wide WebConnected to each other using HypertextPages are written in HTMLWorks on Client/server model
Web Site Structure
First page is called the Home PageOther pages are organized in one of
three possible typesTree Linear random
Tree structure
Home page
pagepage
page page
page page
pagepage page pagepage page
Linear Structure
Home Page
Page
Page
Page
Page
Page
Random Structure
Home Page
Page
Page
Page
Page
Page
Page
Page
Page
How Web Browsers Work
Web Browsers interpret and display web pagesHTMLDHTMLXMLScriptsApplications and programs
Helper appsPlug-ins
Web Browsers
Two most popular and competitive browsers Internet ExplorerNetscape NavigatorBoth have very similar features
Web Codes Successful Transactions
200 The request was fulfilled. 201 The POST request was completed successfully. 202 Request accepted for processing of unknown type. Rare. 203 Request partially fulfilled.
Redirection Transactions 301 The requested resource has been permanently moved to a new URL. Usually accompanied by
Location: newURL which automatically connects to the new URL. 302 Requested resource found, but at a different URL. You'll get a 302 Redirection if you omit the
trailing slash when pointing at a directory (sometimes called a malformed request). 304 Unmodified data not returned in response to a GET request with the If-Modified-Since field. Occurs
when a browser requests data found in cache. Error Messages
400 Error in request syntax. 401 Request requires an Authorization: field, and the client did not provide one. This response is
accompanied by a list of acceptable authorization schemes use WWW-Authenticate response headers. Error 401 can be part of a client/server dialogue to negotiate encryption and user authentication schemes.
402 The requested operation costs money, and the client did not specify a valid Chargeto field. 403 Request for forbidden resource denied. 404 Requested resource not found. 500 The server has encountered an internal error and cannot continue processing your request. 501 Request okay but denied because server doesn't support transaction method.
How Markup Languages Work
Markup languages contain two things Content Instructions on how to format content (tags)
Markup languages are NOT programming languages
3 types of markup languages exist on the WWW HTML and xHTML DHTML XML
HTML
Uses <tags>content</tags>Latest version n HTML 4.01
Full specification available at http://www.w3.org/TR/html4/
HTML can be written with any text editor but specialized HTML editor have been developedWe will be using Macromedia Dreamweaver
2004 in this class
Example HTMLs
Block Level TagsText FormattingUsing ImagesTablesFrames
DHTML
DHTML is Dynamic HTML Allows changes to the HTML “on the fly” Great for animation and special effects
Uses 3 Technologies Document Object Model (DOM)
tracks every object and element on a web pages Cascading Style Sheets (CSS)
Formatting and style information for a web pages Client-Side Scripting
Provide access to DOM and CSS to change them
Example DHTML
Lots of examples available on the webW3Schools.com
http://www.w3schools.com/dhtml/dhtml_examples.asp Olagam
http://www.olagam.com/tech3/dhtml-code.htm Game written by COS 381 students
http://perleybrook.umfk.maine.edu/classes/cos381/jumble1.htm
How XML works
Allows the creation of new markup languagesMake your own tags that have special
meaning for a group of peopleThere is no presentation information in an
XML document Example XML
http://perleybrook.umfk.maine.edu/examples/planes.xml
How XML works
XML languages are defined in Data Type Definitions
http://perleybrook.umfk.maine.edu/examples/planes.dtd Schemas
http://perleybrook.umfk.maine.edu/examples/planes.xsd XML pages are formatted with
CSS http://perleybrook.umfk.maine.edu/examples/planescss.xml http://perleybrook.umfk.maine.edu/examples/planes.css
XLST http://perleybrook.umfk.maine.edu/examples/xslplanes.xml http://perleybrook.umfk.maine.edu/examples/xslplanes.xsl
How XML works
XMLDocument
DTDDocument Type
DefinationsXML
Schemas
CSSXSLT
Style Sheets
BrowserDisplay
Future of XML
XML is the lingua franca for Net Services, Microsoft’s .NET, Oracle, and many other Internet based distributed architectures.
All of HTML can be done in XML and has been in xHTML
XML resources www.xml.com www.xml.org http://www.w3.org/XML/
For next class
Finish reading through Chapter 28Assignment # 2 will be postedGet ready for exam on Feb 3