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Chapter 16The World Wide Web2Chapter GoalsCompare and contrast the Internet and the World Wide WebDescribe general Web processingWrite basic HTML documentsDescribe several specific HTML tags and their purposes3Chapter GoalsDescribe the processing of ava applets and ava server pagesCompare and contrast HTML and !MLDefine basic !ML documents and their corresponding DTDs"#plain ho$ !ML documents are vie$ed4The World Wide WebThe Web%n infrastructure of information combined and the net$or& soft$are used to access itWeb page% document that contains or references various &inds of dataLinks% connection bet$een one $eb page and anotherWhat are the links used for?5The World Wide WebWebsite% collection of related $eb pagesWeb browser% soft$are tool that retrieves and displa's eb pagesWeb server% computer set up to respond to re(uests for $eb pages6The World Wide WebUniform eso!r"e Lo"ator #UL$% standard $a' of specif'ing the location of a Web page) containing the hostname) *+*) and a fileWhat is the relationship between the Internet and the Web?%The World Wide Web&ig!re '6(' ) browser retrieving a Web pageWhy is the expression"visiting a website" confusing?*+ear"h ,ngines+ear"h ,ngine% $ebsite that helps 'ou find other $ebsitesCan you name at least two?How do they work?-.nstant /essaging.nstant messaging #./$%n application that allo$s people to send and receive messages in real time,-oth sender and receiver must have an IM running,Most IM applications use a proprietar' protocol that dictates the precise format and structure of the messages sent,Instant messages are not secure'0Weblogs1log or Weblog%n online .ournal or ne$sletter that is fre(uentl' updated and intended for public consumptionDo you have a blog?Do you read blogs?''CookiesCookie% small te#t file that a $eb server stores on 'our local computer/s hard dis&,% coo&ie contains information about 'our visit to the site ,Coo&ies can be used to determine number of uni(ue visitors to the site to customi0e the site for future visits to implement shopping carts that can be maintained from visit to visit,Coo&ies are not dangerous'22T/L23perte4t /ark!p Lang!age #2T/L$The language used to create or build a Web page/ark!p lang!age % language that uses tags to annotate the information in a documentTagsThe s'ntactic element in a mar&up language that indicates ho$ information should be displa'ed'32T/L&ig!re '6(2) marked5!p do"!ment'42T/L&ig!re '6(3The +t!dent 63nami"s Web page as displa3ed in 7ets"ape 7avigator'52T/L&ig!re '6(4The 2T/L do"!ment defining the +t!dent 63nami"s Web page'62T/LTags are enclosed in angle brac&ets 123 3 3 45Words such as H"%D) TITL") and -6D7 are called elements and specif' the t'pe of the tag Tags are often used in pairs) $ith a start tag such as 2-6D74 and a corresponding end tag $ith a + before the element name) such as 2+-6D74'%2T/LThe bro$ser determines ho$ the page should be displa'ed based on the tagsThe bro$ser,Ignores the $a' $e format the HTML document using carriage returns) e#tra spaces) and blan& lines,Ta&es into account the $idth and height of the bro$ser $indo$,8eformats the contents to fit 'our bro$ser $indo$'*1asi" 2T/L &ormatting294 3 3 32+94 specif' that te#t should be treated as a separate paragraph2C":T"84 3 3 32+C":T"84 center information in the bro$ser $indo$2-4;2+-4 bold information2I4;2+I4 italici0e information2H84 insert hori0ontal rule across page'-1asi" 2T/L &ormatting2?*http@++$$$3cs3ute#as3edu+users+ndale+labs+factorial+>act-'te3htm*4>actorialA-'te2+%42+94222T/L57ew Tags2section4 to define section of pages2header4 to define the header of a page2footer4 to define the footer of a page2nav4 to define the navigation elements on a page2article4 to define an article or primar' content of a page2aside4 to define secondar' content that might appear in a sidebar2figure4 to define images that annotate an article238ava )pplets8ava applet% ava program designed to be embedded into an HTML document) transferred over the Web) and e#ecuted in a bro$ser2942%99L"T code ? *>act-'te3class* $idth?BCD height?1CD42+%99L"T42+94248ava )pplets"#ampleContents of >act-'te3htm@2H14>actorial $ith -'te 8esult2+H14294"nter increasing values beginning $ith D and record the results of the >actorial of 'our input3 %t some point) the ans$er $ill seem strange3 8ecord $hat seems strange about the ans$er and return to the previous page3 2+942942H842+942942%99L"T code ? *>act-'te3class* $idth?BCD height?1CD42+%99L"T42+94>act-'te3classcontains theava applet258ava +erver 9ages8+9 +"riptlet % portion of code embedded in an HTML document designed to d'namicall' contribute to the content of the $eb page8ava +erver 9age% $eb page that has a E9 scriptlet inter$oven among the HTML content268ava +erver 9ages% E9 scriptlet is encased in special tags beginning $ith 2F and ending $ith F4Imagine E9 scriptlets as having the e#pressive po$er of a full programming language2%8ava +erver 9agesE9s are e#ecuted on the server side $here the $eb page resides-' the time it arrives at 'our computer) all active processing has ta&en place) producing a static 1though d'namicall' created5 $eb pageE9s are particularl' good for coordinating the interaction bet$een a $eb page and an underl'ing databaseCompare and contrast avaapplets and !" scriptlets2*:/L,4tensible /ark!p Lang!age #:/L$% language that allo$s the user to describe the content of a document,HTML describes ho$ a document should loo&,!ML describes a documentGs meaning/etalang!age% language for tal&ing about) or defining) other languages!ML is a metalanguage2-:/LLi&e HTML) an !ML document is made up of tagged data&ig!re '6(5)n :/L do"!ment "ontaining data abo!t books30:/L6o"!ment T3pe 6efinition #6T6$ % specification of the organi0ation of the documentThe structure of a particular !ML document is described b' its corresponding DTD document&ig!re '6(6The 6T6 do"!ment "orresponding to the :/L books do"!ment:/L!ML represents a standard format for organi0ing data $ithout t'ing it to an' particular t'pe of output,4tensible +t3lesheet Lang!age #or :+L$ % language for defining transformations from !ML documents to other output formats&ig!re '6(%)n :/L do"!ment "an be transformed into man3 o!tp!t formats32,thi"al .ss!esGambling and the .nternetWhen did gambling explode on the Internet?Internet sites provide what types of gambling?Why is Internet gambling a problem for the states?33Who am .;#ill $atesand Ihave somethingin common%Do youknow whatit is?H Han& Morgan+9hoto 8esearchers) Inc3346o 3o! know;What does the expression "dancing spiders of $oogle" mean?What do computers have to do with "going green"?Why are standards essential?