Transcript WEB 2.0 László Daragó Ph.D Associate professor Semmelweis University Institute of Developing and Education in the Field of Health Informatics WEB 2.0 • The user (client)

WEB 2.0
László Daragó Ph.D
Associate professor
Semmelweis University
Institute of Developing and Education in the Field of Health Informatics
WEB 2.0
• The user (client) also determines the content of
the websites.
• Tim O’Reilly: What Is Web 2.0?
Design Patterns and Business Models for the
Next Generation of Software
• Blog, wiki, podcast, RSS (Rich Site Summary)
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WEB 1.0 vs WEB 2.0
DoubleClick
Google AdSense
Ofoto
Flickr
Akamai
BitTorrent
mp3.com
Napster
Britannica Online
Wikipedia
personal websites
blogging
evite
upcoming.org and EVDB
domain name speculation
search engine optimization
page views
cost per click
screen scraping
web services
publishing
Participation
content management systems
Wikis
directories (taxonomy)
tagging ("folksonomy")
stickiness
syndication
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WEB
• WEB: World Wide Web, WWW
• The World Wide Web (commonly shortened to the Web) is a
system of interlinked, hypertext documents accessed via the
Internet. With a web browser, a user views web pages that may
contain text, images, videos, and other multimedia and
navigates between them using hyperlinks. The World Wide
Web was created in 1989 by Sir Tim Berners-Lee from the
United Kingdom, and Robert Cailliau from Belgium, working
at CERN in Geneva, Switzerland. Since then, Berners-Lee has
played an active role in guiding the development of web
standards (such as the markup languages in which web pages
are composed), and in recent years has advocated his vision of
a Semantic Web.
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WEB
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GNU
GNU is a computer operating system composed entirely of free software. Its
name is a recursive acronym for GNU's Not Unix, which was chosen
because its design is Unix-like, but differs from Unix by being free
software and by not containing any Unix code. GNU was founded by
Richard Stallman and was the original focus of the Free Software
Foundation (FSF).
• According to Stallman, the name was inspired by various plays on words,
including the song The Gnu.
• The goal was to bring a wholly free software operating system into
existence. Stallman wanted computer users to be free, as most were in the
1960s and 1970s: free to study the source code of the software they use,
free to share the software with other people, free to modify the behaviour of
the software, and free to publish their modified versions of the software.
This philosophy was published in March 1985 as the GNU Manifesto.
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How the WEB works
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Viewing a web page on the World Wide Web normally begins either by typing the
URL of the page into a web browser, or by following a hypertext link to that page
or resource. The first step, behind the scenes, is for the server-name part of the URL
to be resolved into an IP address by the global, distributed Internet database known
as the domain name system, or DNS. The browser then requests the resource by
sending an HTTP request to the web server at that IP address. In the case of a
typical web page, the HTML text is requested first and parsed by the browser,
which then makes additional requests for graphics and any other files that form a
part of the page in quick succession. When considering website popularity statistics,
these additional file requests give rise to the difference between a single 'page view'
and an associated number of server 'hits'.
The web browser then renders the page as described by the HTML, CSS, and other
files received, incorporating the images and other resources as necessary. This
produces the on-screen page that the viewer sees.
Most web pages will themselves contain hyperlinks to other related pages and
perhaps to downloads, source documents, definitions and other web resources.
Such a collection of useful, related resources, interconnected via hypertext links, is
what has been dubbed a "web" of information. Making it available on the Internet
created what Tim Berners-Lee first called the WorldWideWeb in 1990.
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History of WEB
• The Web required only unidirectional links rather than
bidirectional ones. This made it possible for someone to link to
another resource without action by the owner of that resource.
It also significantly reduced the difficulty of implementing
web servers and browsers (in comparison to earlier systems),
but in turn presented the chronic problem of link rot. Unlike
predecessors such as HyperCard, the World Wide Web was
non-proprietary, making it possible to develop servers and
clients independently and to add extensions without licensing
restrictions.
• On April 30, 1993, CERN announced that the World Wide
Web would be free to anyone, with no fees due.
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WEB based on three standards
• Uniform Resource Locator (URL), individual
locator of the document.
• A Hyper Text Transfer Protocol, (HTTP), the
protocol of sending and receiving data.
• A Hyper Text Markup Language, (HTML), the
way of information coding to display on
several types of client.
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Standards
World Wide Web Consortium (W3C)
• TCP/IP
Transmission Control Protocol / Internet Protocol
193.6.211.34
• URI (URL, URN)
Uniform Resource Identifier
(Uniform Resource Locator / Uniform Resource Name)
http://www.sote.hu
• DNS
Domain Name System
www.sote.hu < - > 193.6.211.34
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URI
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A Uniform Resource Identifier (URI), is a compact string of characters used to
identify or name a resource. The main purpose of this identification is to enable
interaction with representations of the resource over a network, typically the World
Wide Web, using specific protocols. URIs are defined in schemes defining a
specific syntax and associated protocols.
A URI can be classified as a locator or a name or both. A Uniform Resource
Locator (URL) is a URI that, in addition to identifying a resource, provides means
of acting upon or obtaining a representation of the resource by describing its
primary access mechanism or network "location". For example, the URL
http://www.wikipedia.org/ is a URI that identifies a resource (Wikipedia's home
page) and implies that a representation of that resource (such as the home page's
current HTML code, as encoded characters) is obtainable via HTTP from a network
host named www.wikipedia.org. A Uniform Resource Name (URN) is a URI that
identifies a resource by name in a particular namespace. A URN can be used to talk
about a resource without implying its location or how to dereference it. For
example, the URN urn:isbn:0-395-36341-1 is a URI that, like an International
Standard Book Number (ISBN), allows one to talk about a book, but doesn't
suggest where and how to obtain an actual copy of it.
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URL
http://193.6.211.34
We don’t like long numbers:
http://www.sote.hu:80
http://www.sote.hu
www.sote.hu
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How the communication works
Client
(browser)
Server
Router
Router
Router
Radnai András
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HTTP
specifies the way of sending and receiving information
Sender:
X IP address
Addressed:
Y IP address
Data:
Request
Sender:
Y IP address
Addressed:
X IP address
Data:
Response
Radnai András
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HTML
HTML, short for Hypertext Markup Language, is the predominant markup
language for web pages. It provides a means to describe the structure of text-based
information in a document — by denoting certain text as headings, paragraphs,
lists, and so on — and to supplement that text with interactive forms, embedded
images, and other objects. HTML is written in the form of labels (known as tags),
surrounded by angle brackets. HTML can also describe, to some degree, the
appearance and semantics of a document, and can include embedded scripting
language code which can affect the behaviour of web browsers and other HTML
processors.
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
<html>
<head>
<title>
Title of the frame</title>
<meta http-equiv="Content-type" content="text/html;charset= iso-8859-2">
(possible more header information)
</head>
<body> Content of the site
</body>
</html>
*XML : Extensible Markup Language
*SGML : Standard Generalized Markup Language (IBM)
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HTML
<form name="f1" action="list_dl_seged.php">
<br>
User:<input type=text name=newuser>
<textarea name=newcomment rows=6 cols=80>mycomment</textarea>
<input name=idevissza type=hidden value=/pub/2006_2/darago/list_dl.php >
<center><INPUT TYPE=submit name=ment VALUE='Add comment' ></center>
<TABLE frame=hsides>
<TR>
<TD><FONT COLOR='#3300FF'><STRONG>User</STRONG></font></TD>
<TD><FONT COLOR='#3300FF'><STRONG>Time</STRONG></font></TD>
<TD><FONT FACE='COMIC SANS MS'><STRONG>Comment</STRONG></FONT></TD>
</TR>
<TR>
<TD><FONT COLOR='#3300FF'>laca:</font></TD>
<TD><FONT COLOR='#3300FF'>2007-09-22 10:22:45 :</font></TD>
<TD><FONT FACE='COMIC SANS MS'>bejegyzés szövege</FONT></TD>
</TR></TABLE>
...
</form>
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HTML
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WEB vs WEB 2.0
documents
WEB (1)
client
server
Name of the document:
Stores the document.
www.sote.hu=www.sote.hu/index.(html, htm, php)
www.sote.hu
http://www.sote.hu/intezetek/?inst_id=124
Serves the request, sends the
requested document to the client.
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WEB vs WEB 2.0
documents
WEB 2.0
server
Client
Naming the document
+ specifying content
Running the server side script,
database communication
database
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WEB vs WEB 2.0
2. The server side script
analyses and separates
WEB 2.0
the parts of the request.
1. Input, pl. www.abc.hu/?x=1 (HTML)(PHP, Java)
6. Actualised document.
client
7. Client side script
(Java, VB, Perl) executes the
included commands.
8. The browser processes the
CSS scripts.
9. Output.
documents
5. Refreshing
The content of
the site.
(PHP, Java)
server
3. The server forwards
The request to the database
manager. (Mysql)
4. The database
manager serves
the request. (Mysql)
database
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WEB 2.0,
client-server architecture
2 vs 3 layers
client
Thick client
(intelligent terminal)
application
server
Thin client
(dumb terminal)
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WEB 2.0, examples
• Forum
• WEB log -> blog
• CaseView
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WEB 2.0 technology
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HTML : Hypertext Markup Language
CSS : Cascaded Style Sheets, Style definition language in the HTML documents
PHP : Hypertext Preprocessor (Personal Home Page Tools), server side script (Zend
Technologies)
Java : Sun Microsystems (originally Oak), the Microsoft also had trying.
Perl : script, mainly for writing CGI scripts
CGI : Common Gateway Interface, protocol standard for clients
AJAX : Asynchronous JavaScript and XML, a technique for interactive web applications to
use only small amount of data to refresh the content of the screen
Script : program language like syntax code, run by interpreter
MySQL : open source coded LAMP (Linux–Apache–MySQL–PHP) database and database
manager (see GNU)
SQL : Structured Query Language: database programming and querying language (DDL (Data
Definition Language), DML (Data Manipulation Language))
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WEB 2.0, embedding
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<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
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<html>
<head>
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<body bgcolor=#FFFF00 >
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<?php
echo date("Y.m.d");
function bigyo($param = '')
{
echo "A bigyo()-ban; az argumentum:'$param'.<br>\n";
}
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//$func = 'bigyo';
//$func('Stex van Boeven');
?>
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<center><FONT SIZE="6">Welcome to Laca Gang Site</FONT><br>
Send <a href="mailto:[email protected]"> me </a>
a pic for make a complete gallery</center>
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<?php
$link = mysql_connect ("localhost","root","" )
or die ("Nem lehet csatlakozni");
echo "<br>Server time:".date("Y.m.d. H:i\n");
$i = 0;
$db_list = mysql_list_dbs();
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$cnt = mysql_num_rows($db_list);
while ($i < $cnt) {
// echo mysql_db_name($db_list, $i) . "\n<br>";
$i++;
}
$a=mysql_select_db("db1",$link) or die ("nem tudom db1-et megnyitn");
// echo "Megnyitva db1<br>";
$eredmeny = mysql_query ("delete from sz_txt where (to_days(now())-to_days(dt))>14")
or die ("Érvénytelen lekérdezés");
<title>Forum for friends of Laca</title>
</head>
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Typical WEB 2.0 services
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www.myspace.com : community site
www.flickr.com : picture gallery
www.wikipedia.hu : lexicon
www.joost.com : tv
http://promonet.hu/apropressz/tvonline.htm : tv
www.simulscribe.com : sound recorder-> text
www.logoworks.com : making logos
www.bliptv.com : amateur movie makers
www.soonr.com : mobile access to databases
www.tinypictures.us : pictures and comments
www.iwiw.hu : community site
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WEB 3.0
Web 3.0 is a term that has been coined with different meanings to describe the evolution of
Web usage and interaction along several separate paths. These include transforming the Web
into a database, a move towards making content accessible by multiple non-browser
applications, the leveraging of artificial intelligence technologies, the Semantic web, the
Geospatial Web, or the 3D web.
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That’s All Folks!
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