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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
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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 • 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
:) 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 Emoticons
Instant Messaging • Differs from chat in that it is one-to-one • Chat one-to-many • Four popular software applications that have little to no interoperability • MSN 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 to • Some 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 system • Save money on long distance • Called Voice over IP or VoIP • Converts Voice (analog) to digital packets and vise versa • Digital 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 Ordinary Telephone Ordinary Telephone IP Packet Frame Relay, ATM, or the Internet PBX with IP Telephony Module PBX with IP Telephony Module
How Web Pages Work • Pages “live” on the World Wide Web • Connected to each other using Hypertext • Pages are written in HTML • Works on Client/server model
Web Site Structure • First page is called the Home Page • Other pages are organized in one of three possible types • Tree • Linear • random
How Web Browsers Work • Web Browsers interpret and display web pages • HTML • DHTML • XML • Scripts • Applications and programs • Helper apps • Plug-ins
Web Browsers • Two most popular and competitive browsers • Internet Explorer • Netscape Navigator • Both 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 developed • We will be using Macromedia Dreamweaver 2004 in this class
Example HTMLs • Block Level Tags • Text Formatting • Using Images • Tables • Frames
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 web • W3Schools.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 languages • Make your own tags that have special meaning for a group of people • There 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
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 28 • Assignment # 2 will be posted • Get ready for exam on Feb 3