New and Upcoming RSF Features – 0.7.2

New and Upcoming RSF Features – 0.7.2 Antranig Basman, CARET, University of Cambridge

Main Heads of 0.7.2 Results • Spring Web Flow integration • As well as release SWF 1.x, trunk and milestone SWF 2.x up to 2.0M3 • Improvements in Navigation idiom • Resulting View Bindings • EntityBeanLocator for automated OTP • EntityBroker "Entity Worlds" support • Numerous minor updates and consistentization • Template-based I18N • Role of leaves and branches clarified with forms http://www2.caret.cam.ac.uk/rsfwiki/Wiki.jsp?page=Roadmap

The Final State of RSF Navigation - I • This refers to navigation following a POST (action cycle) • The Static World: • NavigationCaseReporter, provides a list of static rules which are checked after the action completes public List<NavigationCase>reportNavigationCases(){ // In case of no error, transfer to the SearchResults view return ListUtil.instance( new NavigationCase( new SearchCriteriaViewParams(SearchResultsProducer.VIEW_ID))); }

The Final State of RSF Navigation - II • The Dynamic World: • ActionResultInterceptor (ARI2) • result: outgoing ARIResult record determining navigation • incoming: ViewParameters of current view • actionReturn: any return value from method binding • Your job: munge the elements of result, which contains in particular ViewParameters resultingView • NavigationCases have *already* occurred, can perform fine-tuning of outgoing destination taking account of static rules • ARI2 can be declared both locally (on a ViewProducer) or globally (as a standalone bean) publicinterface ActionResultInterceptor { publicvoidinterceptActionResult(ARIResult result, ViewParameters incoming, Object actionReturn); }

The Final State of RSF Navigation III • The Dynamic World (Structured): Resulting View Bindings (new 0.7.2 feature) • A "deferred binding" – unlike normal EL binding expressions, takes effect *after* all action processing is complete • Same timing as ARI2, but much cleaner semantics • Effect: read any EL path from the final request context after the action, and write it to any EL path in the outgoing ViewParameters • Covers very broad class of "local" detailed navigation rules, including the classic case of navigating to a view depending on a freshly created entity ID publicstaticvoidaddResultingViewBinding( UIParameterHolder holder, String viewParamsPath, String requestPath){

Resulting View Binding Example: • Assign from bean id in model to outgoing ViewParams field (in an OTP model) • Assign directly from incoming to outgoing viewID (but take the other info from NavigationCases) UIForm myform = UIForm.make(tofill, "myForm"); RSFUtil.addResultingViewBinding(myForm, "entityId", "myEntity.new 1.id"); RSFUtil.addResultingViewBinding(myForm, "ManagerProvenanceViewId", "viewParameters.ManagerProvenanceViewId");

RSF Navigation Guidelines • Always use the least powerful system possible • Use NavigationCases where your rules are static • Use ResultingViewBindings for most fine-grained "tweaks" • Fall back to an ARI2 if you have to (typically only really needed now for global navigation interception)

EntityBroker "Worlds" • An "Application Fragment" focused on a particular Sakai entity • Served up at paths like http://server/direct/myentity/3/mystub by the "Direct Servlet" (part of the Entity Broker) • Completely clean URL system, hosted outside the portal • Only requires one Spring definition in a normal SakaiRSF tool UIInternalLink.make(tofill,"modify_title_desc_link", UIMessage.make("modifytemplate.modify.title.desc.link"), new TemplateViewParameters(ModifyTemplateProducer.VIEW_ID, templateId)); UIMessage.make(tofill,"level-header","modifytemplate.level.header", new String[]{currentLevel,new Integer(templateItemsList.size()).toString(),});

Hosting an EntityBroker "World" • Define an "EntityViewParamsInferrer" at application scope: • Registers Entity prefix, as well as determining the default view for an incoming Entity reference <bean class="org.sakaiproject.blogwow.tool.inferrer.BlogGroupRSSInferrer" /> publicclass BlogRSSInferrer implements EntityViewParamsInferrer { public String[]getHandledPrefixes(){ returnnew String[]{BlogRssEntityProvider.ENTITY_PREFIX}; } public ViewParameters inferDefaultViewParameters(String reference){ IdEntityReference ref =new IdEntityReference(reference); returnnew BlogRssViewParams(BlogRSSProducer.VIEW_ID, ref.id,null); } }

Notes on EB Worlds • Could not be more simple (in RSF) • Easy to support in other view technologies (done in Wicket) • Work underway for use as a new breed of Sakai "helpers" • Unlike old Entity "access", hosted from a normal webapp • Need to take responsibility not to "leak" out into non-entity application views yourself, as well as proper security checks (throw SecurityException)

Spring Web Flow • At 1.x, Spring Web Flow is a standard Spring technology for managing conversational, stateful interactions ("wizards" or flows) • Flow transitions are mapped out as a finite state machine, either as XML document or in Java • Powerful features for snapshotting and recovering previous flow states • At 2.x, SWF is evolving to have a greater scope to manage top-level lifecycle and non-stateful interactions

A sample Spring Web Flow • "Sell Item" standard sample, JSF version (binding-free) <?xml version="1.0" encoding="UTF-8"?> <flow xmlns="http://www.springframework.org/schema/webflow" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.springframework.org/schema/webflow http://www.springframework.org/schema/webflow/spring-webflow-1.0.xsd"> <var name="sale" class="org.springframework.webflow.samples.sellitem.Sale" scope="conversation"/> <start-state idref="enterPriceAndItemCount" /> <view-state id="enterPriceAndItemCount" view="/priceAndItemCountForm.jsp"> <transition on="submit" to="enterCategory"/> </view-state> <decision-state id="requiresShipping"> <if test="${conversationScope.sale.shipping}" then="enterShippingDetails" else="processSale" /> </decision-state> <action-state id="processSale"> <bean-action bean="saleProcessor" method="process"> <method-arguments> <argument expression="conversationScope.sale" /> </method-arguments> </bean-action> <transition on="success" to="showCostOverview" /> </action-state>

Using SWF in RSF • All flow-scoped beans are available for normal request-scope injection via RSAC • Launch flows with special ViewParams SWFLaunchViewParams and binding bean SWFLaunchBean • Fire flow events with special ViewParams SWFEventViewParams and binding bean SWFEventBean • Access "SpringMVC-style" binding using SWFBindingBean

Producer interacting with SWF for(Person colleague:person.getColleagues()){ UIInternalLink.make(tofill,"colleague:", colleague.getFirstName()+" "+ colleague.getLastName(), new SWFEventViewParams("select", new PersonViewParams(colleague.getId()))); } UIForm form = UIForm.make(tofill,"form"); UICommand.make(form,"back","SWFEventBean.back"); }

SWF Integration Status • Majority of SWF standard samples have been ported to RSF-SWF and some to plain RSF • Integration with stable release SWF 1.0.4, as well as milestone SWF 2.0M3 • Whilst SWF 1.x sits within RSF as a navigation engine, SWF 2.x can act as the overall controller (Servlet/Portlet) • Both "forwards" and "backwards" integration supported via the same library • RSF AJAX (including UVB) is transparently supported within all SWF versions (see date widget)

I18N updates for 0.7.2 • Template-driven message syntax • Still use UIMessage component for complex cases where formatting required • UIMessage has been updated to accept an array of message codes following Spring "MessageSourceResolvable" semantics • UIVerbatim now accepts a UIMessage to allow rich text messages in .properties files <span rsf:id="msg=my-message-key">I18N message here</span>

Other Minor Updates • UIForms can now become direct branches • Local branch IDs are now optional • Finegrained wildcards for request addressible beans • New "tag elision syntax" of rsf:id="~my-rsf-id" allows "elision" of tag containment level in output markup. • Only top-level branches in component templates are considered for resolution http://www2.caret.cam.ac.uk/rsfwiki/Wiki.jsp?page=Roadmap

The RSF Future • It is Orange • 0.7.3 (early 2008) • Largely bugfixes • New client-side validation using DHTML and AJAX • The final component: UIDimensionalLinkfor idiomatic "portalisation"/"helpers"

The Further Future – 0.8 • RSF 0.8 – Intended for before Paris (summer 2008) • Full use of Java 1.5 Generics to cut down on ViewProducer verbiage, better typesafety during binding phase • Proper alignment with official Spring scopes (request and session) • RSF API and feature set will then be stable for final 1.0 release

New and Upcoming RSF Features – 0.7.2