Author: thomas.heute(a)jboss.com Date: 2010-06-29 08:58:00 -0400 (Tue, 29 Jun 2010) New Revision: 13947 Modified: docs/enterprise/trunk/Reference_Guide/en-US/Portal_API.xml Log: JBEPP-158: Remove note about future JSR-286 support from EPP 4.3 docs Modified: docs/enterprise/trunk/Reference_Guide/en-US/Portal_API.xml =================================================================== --- docs/enterprise/trunk/Reference_Guide/en-US/Portal_API.xml 2010-06-28 09:35:12 UTC (rev 13946) +++ docs/enterprise/trunk/Reference_Guide/en-US/Portal_API.xml 2010-06-29 12:58:00 UTC (rev 13947) @@ -481,166 +481,6 @@ <para>That's it - we now have a user counter that will display it states each time a user logs-in our logs-out.</para> </section> <section> - <title>Achieving Inter Portlet Communication with the events mechanism</title> - <para>The first version of the Portlet Specification (JSR 168), regretfully, did not cover interaction between - portlets. The side-effect of diverting the issue to the subsequent release of the specification, has - forced portal vendors to each craft their own proprietary API to achieve inter portlet communication. Here we will - see how we can use the event mechanism to pass parameters from one portlet to the other (and only to the other portlet).</para> - <para>The overall scenario will be that Portlet B will need to be updated based on some parameter set on Portlet A. - To achieve that we will use a portal node event.</para> - <para>Portlet A is a simple Generic portlet that has a form that sends a color name: - <programlisting><![CDATA[ -public class PortletA extends GenericPortlet -{ - protected void doView(RenderRequest request, RenderResponse response) - throws PortletException, PortletSecurityException, IOException - { - response.setContentType("text/html"); - PrintWriter writer = response.getWriter(); - writer.println("<form action=\"" + response.createActionURL() + "\" method=\"post\">"); - writer.println("<select name=\"color\">"); - writer.println("<option>blue</option>"); - writer.println("<option>red</option>"); - writer.println("<option>black</option>"); - writer.println("</select>"); - writer.println("<input type=\"submit\"/>"); - writer.println("</form>"); - writer.close(); - } -} - ]]></programlisting> - </para> - <para>The other portlet (Portlet B) that will receive parameters from Portlet A is also a simple Generic portlet: - <programlisting><![CDATA[ -public class PortletB extends GenericPortlet -{ - - public void processAction(ActionRequest request, ActionResponse response) - throws PortletException, PortletSecurityException, IOException - { - String color = request.getParameter("color"); - if (color != null) - { - response.setRenderParameter("color", color); - } - } - - protected void doView(RenderRequest request, RenderResponse response) - throws PortletException, PortletSecurityException, IOException - { - String color = request.getParameter("color"); - response.setContentType("text/html"); - PrintWriter writer = response.getWriter(); - writer.println("<div" + - (color == null ? "" : " style=\"color:" + color + ";\"") + - ">some text in color</div>"); - writer.close(); - } - - // Inner listener explained after -} - ]]></programlisting> - </para> - <para>With those two portlets in hands, we just want to pass parameters from Portlet A to Portlet B (the color in - as a request parameter in our case). In order to achieve this goal, we will write an inner Listener in Portlet B - that will be triggered on any WindowActionEvent of Portlet A. This listener will create a new WindowActionEvent - on the window of Portlet B. - <programlisting role="java"><![CDATA[ -public static class Listener implements PortalNodeEventListener -{ - public PortalNodeEvent onEvent(PortalNodeEventContext context, PortalNodeEvent event) - { - PortalNode node = event.getNode(); - // Get node name - String nodeName = node.getName(); - // See if we need to create a new event or not - WindowActionEvent newEvent = null; - if (nodeName.equals("PortletAWindow") && event instanceof WindowActionEvent) - { - // Find window B - WindowActionEvent wae = (WindowActionEvent)event; - PortalNode windowB = node.resolve("../PortletBWindow"); - if (windowB != null) - { - // We can redirect - newEvent = new WindowActionEvent(windowB); - newEvent.setParameters(wae.getParameters()); - - newEvent.setMode(wae.getMode()); - newEvent.setWindowState(WindowState.MAXIMIZED); - - // Redirect to the new event - return newEvent; - } - } - // Otherwise bubble up - return context.dispatch(); - } -} - ]]></programlisting> - </para> - <para> - It is important to note here some of the important items in this listener class. - Logic used to determine if the requesting node was Portlet A.: - <programlisting>nodeName.equals("PortletAWindow")</programlisting> - </para> - <para> - Get the current window object so we can dispatch the event to it: - <programlisting>PortalNode windowB = node.resolve("../PortletBWindow");</programlisting> - </para> - <para> - Set the original parameter from Portlet A, so Portlet B can access them in its processAction(): - <programlisting>newEvent.setParameters(wae.getParameters());</programlisting> - </para> - <!-- - <para> - Modify Portlet B windowmode and/or windowstate (ie, Maximize and place in Edit Mode): - <programlisting> -newEvent.setMode(wae.getMode()); // Mode.EDIT; -newEvent.setWindowState(wae.getWindowState()); // WindowState.MAXIMIZED</programlisting> - </para> - --> - <para> - We still need to register our listener as an mbean: - <programlisting role="xml"> -<![CDATA[<mbean - code="org.jboss.portal.core.event.PortalEventListenerServiceImpl" - name="portal:service=ListenerService,type=test_listener" - xmbean-dd="" - xmbean-code="org.jboss.portal.jems.as.system.JBossServiceModelMBean"> - <xmbean/> - <depends - optional-attribute-name="Registry" - proxy-type="attribute">portal:service=ListenerRegistry</depends> - <attribute name="RegistryId">test_listener</attribute> - <attribute name="ListenerClassName"> - org.jboss.portal.core.samples.basic.event.PortletB$Listener - </attribute> -</mbean>]]></programlisting> - For node events, we also need to declare on which node we want to listen, this is done by modifying - the <literal>*-object.xml</literal> that defines your portal nodes. In this example we want to trigger - the listener each time the window containing the portlet A is actioned. We can add the <literal>listener</literal> - tag to specify that out listener with <literal>RegistryId</literal>=test_listener should be triggered - on events on the embedding object. - <programlisting> -<![CDATA[... - <window> - <window-name>PortletAWindow</window-name> - <instance-ref>PortletAInstance</instance-ref> - <region>center</region> - <height>0</height> - <listener>test_listener</listener> - </window> -...]]> - </programlisting> - Of course we could have added it at the page level instead of the window level. Note that a unique listener - can be specified, the event mechanism is primarily done to let the developer change the navigation state of the - portal, this example being a nice side-effect of this feature. - </para> - <note><para>The portlet 2.0 specification (JSR 286) will cover Inter Portlet Communication so that portlets using it - can work with different portal vendors.</para></note> - </section> - <section> <title>Link to other pages</title> <para>Linking to some other pages or portals is also out of the scope of the portlet specification. As seen previously JBoss Portal offers an API in order to create links