CREE Contextual Resource Evaluation Environment Stewart Waller (Archaeology Data Service, University of York) Portals and Portlets 2006: Portlet development for the CREE project

The CREE project arose from the Joint Information Systems Committee programme: Portals: Investigations into User Requirements Assess, test and document user requirements for Internet-based search tools both through their native interfaces and embedded within portal and non-portal environments in a broad range of user contexts. CREE Contextual Resource Evaluation Environment BACKGROUND: Project Aims:

CREE Contextual Resource Evaluation Environment HEIRPORT : Historic Environment Information Resources Portal

CREE Contextual Resource Evaluation Environment HEIRPORT : Zava(x) Framework

CREE Contextual Resource Evaluation Environment Portlet to replace the Servlet Interface Zava Server Web browser Zavax Client (Mediation + Transformation)

CREE Contextual Resource Evaluation Environment Cocoon outputs plain XML Zavax Client (Mediation) Web browser Zava Server

CREE Contextual Resource Evaluation Environment Portlet to communicate directly with Zavax Mediation Portal Environment Portlet Zava ServerZavax Client (Mediation)

CREE Contextual Resource Evaluation Environment Portlet to communicate directly with Zavax Mediation Portal Environment Portlet Zava ServerZavax Client (Mediation) Portal Environment Portlet Portal Environment Portlet

CREE Contextual Resource Evaluation Environment HEIRPORT lite : implementation Core functionality Exploited the portlet MVC design pattern: Model held in portlet session as Java bean processAction() acts as Controller to send/receive XML, updates model accordingly renderAction passes elements of model, styled using XSLT, to View JSPs

CREE Contextual Resource Evaluation Environment HEIRPORT lite : implementation Extra functionality Notepad Export (rough) Inter Portlet Communication

CREE Contextual Resource Evaluation Environment HEIRPORT lite : search Step 1. The HEIRPORT framework is based upon the CIMI profile allowing for searches based on: What, Where, When, Who, Title, Location by coordinate etc. However, for the purpose of this demonstrator, the portlet has been restricted to a simple What, Where and When search. Step 2. HEIRPORT is based around a multi-threaded model allowing simultaneous Z39.50 searches across a number of different target datasets. The option to choose which targets to query has thus been presented here. Step 3. Pressing the start button begins the search query.

CREE Contextual Resource Evaluation Environment HEIRPORT lite : retrieve Depending on the speed of the various remote targets, the user is eventually forwarded to the target summary screen. At this point, the user can decide to fetch the records from a particular target. The number of records returned and results per page can be configured in the user preferences screen.

CREE Contextual Resource Evaluation Environment HEIRPORT lite : present After HEIRPORT lite has fetched records from a particular target, the user is taken to the results screen as shown here. The query trail is maintained across the top of the results listing. Simple paging links are included. At this point, the user can select several records and choose to add them to the notepad using the update notepad button. Alternatively, the user can choose to view more detailed information for a particular record by clicking on the title of a particular record.

CREE Contextual Resource Evaluation Environment HEIRPORT lite : detail The record details screen provides more information for the particular record. The information here is based upon whatever details the target database contains for that record. Thus, certain records may be sparse whilst others may contain rich information across a number of different fields. The fields are largely based upon the Dublin Core metadata standard. When spatial information is available, a simple map is generated showing the position of the record as a red spot. Also links to various external mapping services are presented.

CREE Contextual Resource Evaluation Environment HEIRPORT lite : notepad Throughout the session, records can be added to the notepad. This acts in much the same way as a typical web- based shopping cart system. That is, the user can add and remove records as he/she sees fit. Using this cart-based system, the user can aggregate information from various searches across different datasets. The ability to export the contents of the notepad in a number of different formats has also been included – although at this point only XML is available as the chosen output format.

CREE Contextual Resource Evaluation Environment HEIRPORT lite : (rough) inter portlet communication JSR-168 has no direct support for Inter Portlet Communication IBMs click-to-action (C2A) cooperative portlet technology found in recent versions of the WebSphere portal API is a good example of how future IPC can be implemented as brokered portlet messaging code to declare portlet extension: if(ses.getAttribute("extMap")==null) { // create ActionURL() for this portlet PortletURL mapURL = res.createActionURL(); // store PortletURL in portlet session with application scope ses.setAttribute("mapURL", mapURL, PortletSession.APPLICATION_SCOPE); // flag portlet is running ses.setAttribute("extMap", "running", PortletSession.APPLICATION_SCOPE); } Using the portlet session to communicate between two portlets in the SAME portlet application: Objects can be stored in either the PORTLET_SCOPE or the APPLICATION_SCOPE. So we can create and store a PortletURL object within the APPLICATION_SCOPE

CREE Contextual Resource Evaluation Environment code to retrieve and amend PortletURL: // declare a new PortletURL PortletURL detailLink; // is Map Extension running? if (ses.getAttribute("extMap")!=null) { // copy the mapURL from the session object detailLink=(PortletURL)ses.getAttribute("mapURL"); } else { // use default PortletURL detailLink=res.createActionURL(); } // amend URL with various action parameters detailLink.setParameter("mode", "details"); detailLink.setParameter("record", recordID); JSR-168 has no direct support for Inter Portlet Communication IBMs click-to-action (C2A) cooperative portlet technology found in recent versions of the WebSphere portal API is a good example of how future IPC can be implemented as brokered portlet messaging HEIRPORT lite : (rough) inter portlet communication Once a PortletURL has been stored in the APPLICATION_SCOPE, Any portlet within the same portlet application can retrieve this as a handle to the specific portlet action method. Not dynamic – portlet actions can only be triggered by clicking on the link rather than by an event

CREE Contextual Resource Evaluation Environment WSRP: web services for remote portlets Used WSRP-4J – Apache Portals Project Encountered various issues: Portlet preferences locked to either WSRP or Pluto depending on which was called first Images didnt always come through Portlet URL didnt always generate correctly WSRP-4J not yet final – still in incubator status

CREE Contextual Resource Evaluation Environment Questions ? End.