Cse120wi11lec24[1] Metatags XML

8/6/2019 Cse120wi11lec24[1] Metatags XML

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3/2/11 2011 Larry Snyder, CSE 2


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3/2/11 (c) 2010 Larry Snyder, CSE 2010 Larry Snyder, CSE

byte (baIt). Computers. [Arbitrary, prob. influenced by bit sb.4 and bite sb.] A group of eight

consecutive bits operated on as a unit in a computer. 1964Blaauw& Brooks in IBM Systems

Jrnl. III. 122 An 8-bit unit of information is fundamental to most of the formats [of the System/360]. A consecutive group ofn such units constitutes a field of length n. Fixed-length fields of

length one, two, four, and eight are termed bytes, halfwords, words, and double words

respectively. 1964IBM Jrnl. Res. & Developm. VIII. 97/1 When a byte of data appears from an

I/O device, the CPU is seized, dumped, used and restored. 1967P. A. StarkDigital Computer

Programmingxix. 351 The normal operations in fixed point are done on four bytes at a time.1968Dataweek24 Jan. 1/1 Tape reading and writing is at from 34,160 to 192,000 bytes per

second.

byte baIt. Computers.Arbitrary, prob. influenced by bit n.4andbite n. A group of eight consecutive bitsoperated on as a unit in a computer. 1964Blaauw &amp.Brooks in IBM Systems Jrnl. III. 122 An 8-bit unit of information is fundamental to most of the formats of the System/

360.&es.A consecutive group of n such units constitutes a field oflength n.&es.Fixed-length fields of length one, two, four, and eight aretermed bytes, halfwords, words, and double words respectively. 1964 IBM Jrnl. Res. &amp. Developm. VIII. 97/1When a byte of data appears from an I/O device, the CPU is seized, dumped,used and restored. 1967 P. A. Stark DigitalComputer Programming xix. 351 The normal operations in fixedpoint are done on four bytes at a time.1968 Dataweek24 Jan. 1/1 Tape reading and writing is at from 34,160 to 192,000bytes per second.


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Metadataisdataaboutdataadescriptionofwhatthedatais

Knowingwhatthedatais,asintheOED,allowsustoprocessitbetterforusers

Heresanexample:SearchOEDfordefofbinary Withoutmetadata,get8,311hitswhichoneisthe

definition?

Withmetadata,geteachdefinitioninorderhow?binary ... ...



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Metadataisdataaboutdataadescriptionofwhatthedatais

Knowingwhatthedatais,asintheOED,allowsustoprocessitbetterforusers

Heresanexample:SearchOEDfordefofbinary Withoutmetadata,get8,311hitswhichoneisthe

definition?

Withmetadata,geteachdefinitioninorderhow?binary ... ...


ThePrinciple:Wecanprogramcomputersto

betterhelpusifweknowwhatthecontentis


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Wehaveseentagsinseveralforms OEDcustomtagscreatedfordictionary HTMLthetagsmarkupthecontentsoitcan

bedisplayed;itsasimpleuseoftagging

Recalltagterminology3/2/11 2011 Larry Snyder, CSE 6


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ImprovingonthemetadataofHTML Metadatadescribeswhatthedatais,but

becausethetagscanbedistinguishedfrom

thecontent,itseparatesitselffromthecontentthatsgood ButHTMLcombinesidentifyingcontent

withsayinghowtoprocessit,i.e.displayit

Bignewidea(notpartofHTML)


Separatethecontentanditstagsentirelyfrom

theprocessingproduceadataonlyfile


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Byseparatingthecontentfromtheprocessingitispossibletomaximize

expertise

Thecontentexpert(you)putsthedatatogether

Theprocessingexpert(someprogrammers)writetheprocessingcodebasedonthetags


DisplayApp

http://blog.flexcommunity.net/lab/ppv3dGallery_slicedCube/


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JustDoIt!


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TheExtensibleMarkupLanguage(XML)isamarkuplanguageinwhichYOUthinkupthe

tagsitisaselfdefininglanguage!

Theusualrulesfortagsapply Enclosein StarttagandEndtag Tagsmustalwaysbematchedorselfterminated

Tagscanhaveattributes(thinkthoseup,too)ofform attributename="valueInQuotes"

Use.xml asthefileextension Alwaysstartwithstandardtext(shownlater)



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SupposeIwanttorecordinformationaboutthisclass;usingXML,Imightwrite:


120M, W, F

Tu,Th

Must-know computing knowledge for the

21st century

L. Snyder

Iinventedthetags;they

makesensetome,andI

couldwritesoftwaretoprocesssuchdescriptions


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Ifyouhaveanydigitaldata,itshouldbetagged,eitherbyyouorbysoftware

ThefactthatXMLisastandardispowerfulourexamplewillbesvg,scalablevectorgraphics

Theidea:specifyall2DgraphicfiguresusingXML,andleavetherendering,thatis,the

drawingofthefigurestoothersoftware OurspecifyingsystemwillbeInkscape Ourrenderingsystemwillbeprocessing



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Inkscapeisalovely,opensourcesystemtocreatedsvggraphics:http://inkscape.org/



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InstallSWanddevelopsome

graphicscake

Savefileasstars.svg



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Surpriseitsa(lot)of

XML Wecantunderstandit,buttheSWcan

itsjustalotofattributes

andtheirvalues



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Processing(andlotsofgraphics

systems)understandtheSVG

primitivesandXMLletsusstructurethe

graphics



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Sincewethinkupthetagsourselves,itstheeasiestlanguageintheworldtolearn,right?

Right.

Itstrivial?! Notquitethereisalittletechnique,and

welldothatnow

Tagscanserveinthreeroles



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IdentitytagitsoyouknowwhatitisGeorge Washington

Affinityallpropertiesofathingshouldbecollectedtogether

George Washington

6 2

WoodenMount Vernon



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Collectionencloseagroupofitemsofthesametypeinacollectivetag

George

John

Thomas

num="44">Barack

Theseusesbecomeintuitivequickly



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UsingXML,giveadescriptionoftheMac



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WecanseethestructureofourXML(andcheckthatitiswellformed)bydisplayingit

inFirefox



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Part1:Setupapicturevieweron

yourowncomputerofyourownpix

http://www.simpleviewer.net/simpleviewer/3/2/11 2011 Larry Snyder, CSE 23


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BuildADiaryUsing

XML



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Thebrowserdisplayspage,buttheSWgivenisalittlelameandalittlelimited!JustFixIt!


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Cse120wi11lec24[1] Metatags XML