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Department af Defeuce Defence Science and ‘Technology Organisation investigating Web Map Service Client Technologies Joel Blyth, Sean Geoghegan and Damian O'Dea DSTO-TN-O536, TION STATEMENT A ec for Public Release Distribution Untimted 20040617 035 Doperaen’ of Beense fence Seco. ‘Telnaes Onion Investigating Web Map Service Client Technologies Joel Blyth. Sear Genghegan ane Damian O'Dea Comumaad and Contzol Division information Sciences Laboratory DSTO-TN-A6 ABSTRACT Web Map Servioes may provage some asistanee in alleiening the Aigh cost of providing Gevopatil Information System {GTS} copabies to Defence uste,Ihis repost discuss the Alocelopment of severe inxplementatons of lien! applicabions of the Web Rap Service nerve. Palins ervauctere ‘nthe se of veto: Web technologies inconstract hu cit plicadon: ate vciein|. Seygestiom ane ako made fer Ature development elfors tu reprove ent Sanctior aly [RELEASE LIMITATION lyst for pic ear STI Tatami Sener Laboratory PO Re 1500 EninbonghSnoth Asien 07 Aston Teleieoues ty 259 5565 ‘an 8 9288 6967 ECommouieth of statis 2608 AN (3 008 Fim es APPROVED FOR PUBLIC RELESST Investigating Web Map Service Client Technologies Executive Summary he cest of provalany al Tuiat Capunand Seppont Frvionment CSR) wsers with 3 Gevspetidl Tilormation Selon AGI) capability and accene le surparling Gaia als i sndiilisely hig Web-hased mapping. senvioes provide a cosceaving by ianlaling Gs :nowvssing capahililes va serve: and prerenting le conrplstec auzp product hoa User fs en tengo. Web mapping systuas typically comist uf une ue roe servers Dit provide mips images tu ange econ apis. ‘Toe investigation ob aitecenl Wah lertnologies in the davetupment of Web: Map Service (WME) claus wes codertaken under the auspices of the LSIO Ladinburgh acation Stent program. Web technologios have evulved grostly ft: sit TIMTL encoded pages, ona orc of ‘use technologies offense nt capabilites In develop client appizalnns. th least All casos Fae bik of tke compotation of ke olism server interaction is conducted in a weer agect suca a8 a Web browser. Uctermining the most saitible tedulogy to be apples to che develupmest of « cent application meles studying, fe beneis that ech approach preserts In this efor, client applicatims were developed using a range of tec'nologies. No Formal expertmentativn wos conduetot 11 gaier dats regoeding the meet oF ene tuchnelogy over another. Instead the stuslen:consating thie implementation stu made ant assestmnent of che ease of applying enck technolagy ty the probkm of developing: WMS Cit ‘An ascsieamnt of de viability of applying the different lechnology to h's problent “niain emo in ae eonclues Sample sora: code from to dient appheations is ial as appendices. No formal ‘design inforation is mesorde, Contents L INTRODUCTION... a BACKGROUND 10 WER MAP SERVICES. » 3. TYPES OF CLIENTS, enneneensnn 3 BA Bimple fink ww nnn ee’ Bt Availahle Funelnalily 3 BQ WML Fortnsecenenenneennnenn ne! 321 | Moths Daderaben, 3 B22 Acgilall Functonity 4 R13 Problems Frog inetre 4 33° Setvet ad SAL Methark altho 5 ABZ Available Buc-nntily 5 SAA Problewes Enecumlered 5 Ad JowoServerit Hayes U!errsnnsssnnnnscna ws Bi) Methods Underiaken, 5 342 Availabe hnetinnaliy’ 7 343 Problems Hncounteed, a 5 Applet on a) SIRT Motto Elnkrtston 7 432 Avnifable Functionaiy 7 353 Problems knananierad 7 4. FUNCTIONALITY OF CUTBRTS ooo ceceenen sh AA Dynamic Content enrnnnern i 22 Zuoming andl Paaning en ” er) 5. OTHER PROBLEMS WHEN BUILDING CHEWS se ncme SA Dexument Type Definitions vn 52 Javabcripterenonnnnna ~ 53 Tamncat Server . 51 Tenage Sive to Bownding, Box Katie snscncnnn 1 EUTURE WORK onnn nee vn wt 6A Multiple Services sono nnn m0 62. Scibéle Layer ” neat] BA Styled Tayer Descriptor Enabled Clieat mosses u 7. CONCLESION. cence seettennnnenense ID APPENDIX A: SOURCE CODE LXAMILES sou penn AL JavaScript Sample Cade -nninonn AZ. Servtet Source Code, ames) pero 1L Introduction Ty rarueyt ofa Web Mop Serviae {WMS} [1] has been developing lorsevarsl seats mos, aad Inday one effort is canted and guidee by the Open C35 Conzortum {OG The GUC enmprises of suoce than 259 compinies, grveaninem agencies) and ‘aniversiies thal me involved ir a emimsss process 2 develop pebiicly available interoperate gerprocersing sprciications. Oper avtcfaces and protocols defined by Open Gis Epeckications offer salu Col “gedeeuntie” dhe Web, ut i wsble gecaphic wnaps foe dlsplyed in a web hrvorser bated wpa ctioie smiled bya user The aim of Us export i to discuss the available technalngies and the mathods tor building sh bated imap, clients A for is plocsd or. ceiving the cist’ ine romps, based upon the stfivully af divekernnt sulted ty Mis tecnulogy, the fools encountered during develagmen’ ann] hoe sumy fs tw inplkerunt varying ogres of fnchonclity. Heo provides a guideline 1 help develypers to Aetoreve Ee te tube tehalogy te butte eb meppieg clients 2. Background to Web Map Services A simple WMS consias ef a ion (ysieally awh brown inteince that sens races toon semer in the form of a Unio: Rescue Tacit {URL} [2]. the OCC WS spovifatiunskrwdarises the way in which clients reqes! mapsand the wy that serves Aescvibe their deta structuco. Cezeenty there are three aperations, the fst (9 ol shih, are mandatary for ary WMS hep xauntaton, Capabilities Obtein service eve! metadata in ‘he form of 9 extenille mask wp nuguage (ML [3] Jucornect that desenbes fhe coment of WM aecwers and seule requess paramese, Map — bial my dtined oy the use 1ge whens geespetial and cher paramelees see Well 4} Getveaturelnio ~ Ask information abut paticlar features show on ama. “The contort af the URL svbmutted ip the server éape ws upon “as lint. Me eliont neces to know the content of Ce carver then a FHC eb mngoust igen. This negucsl eeturas a XML dreumtent ech the available dais. Aa esate oF a Ga pubis rests bel sco of he "STE as ews In Ee 6S gh th technal miembersblp eld by EGO va ll Damas eke, oqo alee Vale ier snqhised map ta be generate scilhin ais baonseer then a Gektep rennet abmitied. "Ihe vequites parameters are eumustsed in Cable = Anensemple of 9 requestis below sg bis Means? er esha ery epee ‘Ek. tstsard eis Crate Re oso Seb eS MOAN Pomatryeseaiecetersgnusiciaekerdar Ll a8cautafahenn iui Paci Dassen = Raqued Verda Regie name TP Gininasaca ca ae mae a or Carinrarated Fel nZone aoe ie, Spel lever System (1 Dovacng boc comers ores te upper igh Tonia] Wilh nc mo pe sigh fpvce on ma iene Dalpal iel op, _. tg kee eT: Regn Pere tie Gatkins rjael be tnooeneety Inralated on requests a sevvice that i rseiable, the server wall return an eacoption in the furn uf ao lage oF a3 ah XBT. document: AB ‘pte Gevitay request parameter oan specfy cian. preference for exacptun report ‘he version nnmiber is an impurtint factor io fhe URT. eacurat 1 alates tn the version of the WMS specfisition to hich He Cienl expects thal the sarees will comply. Lhe specifgainn hag been madi ed and usdaled several deces, su itis wsentl that the torre wersnn he solacad. If te server is unable to suppart the reypested vorsian ob the iameriace there & provision for nsyoiniar. oF « muttnlly secoptable version eceen the dient and server, (Given the vn itentace requoes. a comesen roe ofthe cient to simp the eveation at the UAL resets sat ove sens fu Hho ape. Aor auld have the abst ro eaeyseleut the paramelens thal ere neque. sad send the URL to the serser vithest hating 16 assemble it manly, ey fisd mote details about the Weis Mops Socelie iuplomnntatian <peciticatinn sez hpi /eatecuersinere echee,fimplementation hs 3. Types of Clients ‘This section. explores five Ufa pe allan, neal sige es, ATM. ore, evi, lavaSiras Hees SEs), and apie. The types at clienl re charasteiced by the technol tied tn bad then an the Cunetionality they present ta she ser. Hach implementation 3s characteris by a desceotion ol the technology and met undertaker toimplsment a WME chant Additionally, tne fonetinliy developed for the sleet and problems teccuuefeg8 inthe irmplerentatir. are reported, 3.1 Simple link A Tink version of a WSIS chat can rage Fp 1a ese typing, areqes: URL int the add-ess bar ofa browses, + rnuliple links ta servivenon avieb page thumboaile of anus within « TMT. pape ie the appropriate request she selected 3.1.1 Available Fenetiouality Line nwcleal ponsides eninimal foncsonatity ax tne user may find it d:ffleult or even Aanpevsible ty change the parameters af the map, Fnesetztion to she sur ofthe ‘ink asa simple wand ¢g. "map") or thumbnail mage hula ths aul URL provenls Bue wer Teor (anything ut manually configuring the UL Ceacplx Es a the Kastan Tee of fa web fionrees are nor xendly amelerstitie sand ene diiest by rally oo farsi, The URL fae sxc rap 'sHised on the web page, ma must le manmally fie! to estore the map displayed 32 HIMLFonn A foomn ia section of» TTTBIT.locsreent containing nat ary naval canteet and mark- fp but ola gaia! einen elled enntios(ehackoses, cin buttons, neni, et) that face lela, sera generally “complet” a furm by avdifying it conte: fouecing xt, elesting mem iteam, c), hetore submitng thn fer ta tee server tor processing, The Cantenf of he creeks make np Uneaten of We URL that an to she sever S21 Mths Uaderlaken A siete FITMT, page with to hace has bu developed, One frase comtzins a fom land ‘ls conamls, nad tae uther provides browser ace whore the sehimied uy bs tfeplayed (cummunly brown 96a lage ears A nwor type /iv eels dillon: values for he ermine 266 subrmis efor In tae serve Dy chshug Bullen ‘abelled “Gat lap", The valses of the enactn’ make up paramctins of the GMap recuest UBL. Tae server tunis bua, rset an the inp jpucaunelos in the opposise same 422. Available Tuxslioaality There 1s evinirw) furvtinnaliy bacomse the wer Is to knwgse whet the availae panos ofthe map server are, befune Eling out the Foc. 1 one of the paramelar is Enworrect the sovver wil ther retum an excepts or provide an image thar the user waa notewpeeting 3.2.3. Problems Encountere ‘A problem thot wt ernie vith LUMI Ferm was But some usor agents Ce we brnsserl sibrily perfarmac, URL encuding mutation and cera web map servers were rule 0 a wih fw alested not to Saar the rota. “The encovtng notation repleves reseese shales wit «three sharacier representation, “This ea pereentsge. and tro hexaevimel igi whoae value covvargords to the pariion of the charartar im the ASCII charactor cel. For exaraplea space i converted th 420 sea Cute, The encoding is deseztbed in detailin ‘ia converted ‘The OU: specification states tht 9 comme must separate cach layer of the map request and cach bowslueg 20 Vala, Whea seeding a megaest frum a form, these comma Guortiss are noplaced wilh thelr encoding by the user agent In the eet ot he svar nal reragniting be otatin, i does wot teongite the novalia af list elernet doimate When a server is incapublial dealing with thesernotativns, av exceptions wetorued for an cothonscnn Tei nate reg 1 yo found that macy of che veel mapping soverrs Aad wary ele conformance tn the OGC Implementstion Specification snd id mot allow fr the sliiey fs agli He tccoding, One server that canfounns stil ta te speification waa Cubelers. Wher Unying to acess a CabeW¥ urs gwen eam a ‘ores, an excep: i alway etuueeé. am Ee server stating that the Bonding how's vious ace incoresL, The ESRI WMS cormoctor 0 the ArcIMS server was capable uf eyprarling, ws|uests from » HT. form. The ESR server comtectly panes the ur«uilné TR. and forwards the recuest om to the Aelia server ferprecestng, The OGC membership i avane of the naw sill he WMS Version LL and sake to resolve i hy revision of the relents ns The spaelizatin, 33 Servlet A serve: iva sersortile so iare component, waiter, in Java, that djauretsly enters fe fimelwnutity af a web secren, Unlike appiuts, servlete do net display # qraphical ines ithe uses, serves work i one behind the scenes” on the server ad only the mos the sorcery anes HEN nga omtur Hae Cat Guy i ne foo. ‘The moriertion use a servlet io provide dymame wel pages. Tn this cae the TAME layer, bounding box values avd other attributes of the map ave aulomalically generated shan the web page is fit opened, ‘this is dome by parsing the dacuesent thal it lured Ly the server Lr zesponse toa CotCopmbdines rest ay dbcnuse im Section 8, Fora serie to generate HITT, i vequies Java Poni ier thi, ue Fava soucus fis, for xara r.nckfontent ypsal ems H LY fotiprint'= pci") gut puintis iaveyarrayit|is £¢ 99 axzay saat eontalne Ge caver Amone piel Ht of the cod devel ia neice io Appensty A2. 33,1 Metkods Liderlaken, Lc tthe fact tant sucvlet fe dtc to mudily becsrve of the integrin of fara and TITML cue, st wos four at t yo let to first exeate andl act the HABIL page using stood ity desig prog oe plbcciatlers uiserted dtu euntrals of te page Bow te TEM parameters After completing the desig of the page the HIM endl i enpien inka the servlet sous Biv, Dyzuanic canton! gunceatud by pansng the GoiCaqudbiee XML document, replaced tho plaedholie- element 32 Available Functionality Servlets ore capable of suppenting ill -he function sty caudex in Section 4, Modifying ‘su pasting gorse! oes i several pens ae disease below 333 Problems Eneauntored ‘Changing tke lnok and fee of the applicaian, a sling, supine kw sew tea lent, reqpites the surclet code to 2 updated, reanmpiled ond then rele ved on the esrvee, which isan nlasive pou ‘Taking advantage of weel-ange doceluymunt tuuls when designing the application Intertace is elfical.T gue oats ate used 10 Develop the seb page ‘ayet the generated HLUML mast then he manually exnkedded inio the sereor code. Tres groves fe ime sconscraing and emer ferme