Advanced Web Systems 4- PORTLET API specifications (JSR 286) A. Venturini

Transcription

1 Advanced Web Systems 4- PORTLET API specifications (JSR 286) A. Venturini

2 Contents Summary from jsr 168 Needs addressed by JSR 286 Analysis of the Portlet API specification

3 JSR-168 Portlet API Portlet Requests Preferences User information Security Deployment packaging Portlet Container Extension of servlet container Contract between component and container

4 Portal and Portlet Interaction B A C User Action on B Portal Do action on B Portlet container processaction Portlets A B C Render A render These requests may be done in parallel Render B Render C render render A B C Outside of the scope of the Portlet specification Scope of the Portlet specification

5 JSR 286 JSR 168 and JSR 286 are specifications defined by the JCP, Java Community Process Program JCP is Program for the development and revision of Java technology specifications, introduced by SUN Specifications led by Martin Scott Nicklous (IBM) Expert group formed by the major players (Oracle, Sun, Vignette, BEA, Liferay, Red Hat, TIBCO ) s/final/jsr286/index.html

6 Goal of JSR 286 The new Portlet Specifications add functionality that was not addressed in the first version specification Inter-portlet communication Public render parameters Portlet filters (we will not cover)

7 Extension introduced by JSR 286 JSR 286 allows portlets to send and receive events

8 JSR286: Public render parameters Public render parameters allow sharing of request parameters across different portlets 8

9 JSR-286: Serving resources JSR 168: you could not serve dynamically generated resources directly through the portlet Overcome with additional servlet. But: You do not have the portlet context available (no portlet session, no user login data, no preferences ) JSR 286: SERVE RESOURCE Be able to produce XML REST SERVICES JSON AJAX Exploiting portlet information: Configuration, security, preference 9

10 Serving Resources: JSR 168: servlet JSR 286: portlet serve resources 10

11 Resource Serving Generate non-markup Content Images PDF Supports Simple AJAX New Lifecycle Method serveresource New URL Type ResourceURL No Interportlet Coordination in serveresource

12 JSR 286: Cookies, document head section elements, and HTTP headers Two-part rendering life-cycle call: Render Header Render Markup You can set cookies at the response of each lifecycle method 12

13 JSR 286 API Portlet Interface (JSR 168) EventPortlet Interface ResourceServingPortlet Interface The GenericPortlet abstract class implements those interfaces with default functionalities

14 Request lifecycle as extended by JSR286

15 Action Request (1) in response to an action request the portlet updates its state The processaction method of the Portlet interface receives two parameters: ActionRequest and ActionResponse The ActionRequest object provides access to, parameters of the action request, the window state, the portlet mode, the portal context, portlet session and the portlet preferences data Only in the processaction the portlet may redirect the user to a specific URL

16 Action Request (2) During the processing of an action request, the portlet may set in the ActionResponse object render parameters to be passed to the portlet render cycle The portlet may publish events via the actionresponse.setevent method publish state changes or other notifications to other portlets

17 Event Request Events used communicate between different portlets. EventPortlet interface defines the processevent method (EventRequest and EventResponse parameters) EventRequest provides access to: event payload, window state, portlet mode, render parameters, portal context, portlet session and portlet preferences portlet can set in the EventResponse object new render parameters The portlet can publish events via the EventResponse setevent method (notifications to other portlets)

18 Render Request Portlet Interface, render method receives two parameters, RenderRequest and RenderResponse RenderRequest object provides access to: parameters of the render request, the window state, the portlet mode, the portal context, the portlet session and the portlet preferences data The portlet can produce content using the RenderResponse writer or it may delegate generation of content to a servlet or a JSP

19 EventPortlet Interface to receive events the portlet must implement the EventPortlet The portlet container will call the processevent method for each event targeted to the portlet with an EventRequest and EventResponse object Events are a lifecycle operation that occurs before the rendering phase The portlet issue events via the setevent method during the action processing. The event payload must have a valid JAXB binding, or be in the list of Java primitive

20 Sending Events In the processaction

21 Receiving Events The portlet can access the event that triggered the current process event call by using the EventRequest.getEvent method This method returns an object of type Event encapsulating the current event name and value

22 Possible Example 1) processaction 2) setevent(eventpayload) 4) render() Product Catalogue Portlet Portal 3) processevent() 5) render() Shopping Cart Portlet

23 serveresource

24 Resource Request ResourceServingPortlet interface, serveresource method, receives as parameters ResourceRequest and ResourceResponse. ResourceRequest object provides access to information such as the parameters of the resource request, the input stream, the window state, the portlet mode, the portal context, the portlet session and the portlet preferences data The portlet can produce content using the ResourceResponse writer or output stream, or it may delegate the generation of content to a servlet or a JSP.

25 Portlet URLs client requests are triggered by URLs created by portlets. These URLs are called portlet URLs. The URL can be of three types: ActionURL Full lifecycle, one processaction, possibly processevent calls, one or more render requests. RenderURL. Translates into many render requests, one per portlet in the portal page. ResourceURL (added by JSR 286). Translates into a serve resource request

26 Public Render Parameters Normally, each portlet has its own parameters Avoid the possibility that one portlet uses parameters meant for another portlet. Sometime this is a limitation. Public render parameters are intended for sharing view state across portlets Enables the end-user using the browser navigation and bookmarking if the portal stores the render parameters in the URL.

27 Usage Example A page with 2 portlets: Weather portlet Map portlet The page display information about a city passed as parameter Weather Weater Portlet Map Map Portlet

28 Examples Examples for actions, events and public parameters in the lab.