1. Sept 12-17 2004NVO Summer School1 Cone, SIAP, and OpenSkyQuery Client Development Gretchen Greene, Maria Nieto-Santisteban T HE US N ATIONAL V IRTUAL O BSERVATORY

2. Sept 12-17 2004NVO Summer School2 This session explores Basic client development for standard http VO services –How-to for building tools, applications JAVA examples provided in course nvoss\dev files Cone client, SIAP client, and skyportalclient tutorial on the Twiki site (from SS program) –http://chart.stsci.edu/twiki/bin/view/Main/SummerSchoolClientSidehttp://chart.stsci.edu/twiki/bin/view/Main/SummerSchoolClientSide –http://chart.stsci.edu/twiki/bin/view/Main/SummerSchoolSIAPClienthttp://chart.stsci.edu/twiki/bin/view/Main/SummerSchoolSIAPClient Basic Web service clients How to manipulate standard VO response –XML VOTable parsing –SIAP output FITS Assumes some prior knowledge of service availability –Registries integration for locating services will be discussed tomorrow (Plante/Graham)

3. Sept 12-17 2004NVO Summer School3 Current Client interfaces to VO protocols VO DAL (Data Access Layers) returning VOTables –Cone Search: http Catalog access –Simple Image Access Protocol (SIAP) http retrieves image references –Simple Spectral Access Protocol (SSAP) still beta and not presented here OpenSkyQuery portal –Web service (SOAP) programmatic interface removes limitations of portal –Returns classes and operations including VOData

4. Sept 12-17 2004NVO Summer School4 HTTP protocol PROS HTTP Interfaces return a standard VOTable –IVOA standard (current Version 1.1) –Several parsers exist: JAVOT, SAVOT, Perl, C++ http://www.ivoa.net/twiki/bin/view/IVOA/VOTableSoftware#Par sers –Suite of compatible tools available: http://www.ivoa.net/twiki/bin/view/IVOA/VOTableSoftware#Ap plications Language independent: network protocol based cgi is easy to implement

5. Sept 12-17 2004NVO Summer School5 HTTP protocol CONS Returns only VOTables –Limited simplistic Metadata, i.e. fields, UCDs, etc. Registries will contain more meta information yet still dependent on standard exchange –VOResource Schema design description level of resources/services: –e.g. Invocation methods, resource Relationships, coverage,+ Requires parsers Query input parameter limited –ra,dec,sz

6. Sept 12-17 2004NVO Summer School6 Future for Client Development Continue to support basic http protocols: Cone, SIAP, SSAP More Web service / SOAP based –Contemplate DALs with Web service protocols –Wrappers for legacy services –Newer tech OpenSkyQuery-like tools –XSD schema can use WSDL to class auto-generation tools language interoperability –Receiving classes instead of fixed tables Complex Clients –Science applications which integrate multiple basic clients –Integrate VO standards with new and existing tools