Re: Linking Between Portlets

Hi,

 

Here is an example of 2 portlet A and B. Portlet A displays links and 
portlet B displays a result depending on clicked link.

 

1) First you have to specify the  2 portlets, A and B, in the 
portlet.xml file.

 
Example of portlet.xml

-----------------------------------------

<?xml version="1.0" encoding="UTF-8"?>

<portlet-app xmlns="http://java.sun.com/xml/ns/portlet/portlet-app_1_0.xsd"

             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

             xmlns:portlet="http://java.sun.com/xml/ns/portlet"

             
xsi:schemaLocation="http://java.sun.com/xml/ns/portlet/portlet-app_1_0.xsd" 
version="1.0">

    <portlet>

        <portlet-name>PortletA</portlet-name>

        <portlet-class>jahia.portlet.PortletA</portlet-class>

        <expiration-cache>0</expiration-cache>

        <supports>

            <mime-type>text/html</mime-type>

            <portlet-mode>view</portlet-mode>

        </supports>

        <portlet-info>

            <title>Portlet A</title>

        </portlet-info>

    </portlet>

    <portlet>

        <portlet-name>PortletB</portlet-name>

        <portlet-class>jahia.portlet.PortletB</portlet-class>

        <expiration-cache>0</expiration-cache>

        <supports>

            <mime-type>text/html</mime-type>

            <portlet-mode>view</portlet-mode>

        </supports>

        <portlet-info>

            <title>Portlet B</title>

        </portlet-info>

    </portlet>

</portlet-app>

 

2) Portlet A displays all links and deal with request like this

a) processAction(...){

  - read value of parameter "action"

  - store value of the parameter in the session with scope 
APPLICATION_SCOPE in order to be accessible by all portlets and servlet 
that belong to this application (In this case, PorletA and PortletB)

}

 

b) doView(...){

  - display links with different values for parameter "action"

}

 

Example of code for PortletA

-----------------------------------------------

package jahia.portlet;

 

import javax.portlet.*;

import java.io.IOException;

import java.io.Writer;

public class PortletA extends GenericPortlet {

    public static String ACTION = "action";

 

public void processAction(ActionRequest request, ActionResponse response) {

        // get action

        String action = request.getParameter(ACTION);

        if (action != null) {

            action = "1";

        }

 

// important: set the parameter in Application scope in order.

        request.getPortletSession().setAttribute(ACTION, "1", 
PortletSession.APPLICATION_SCOPE);

 

}

 

public void doView(RenderRequest request, RenderResponse response) 
throws IOException {

        // first set content type

        response.setContentType("text/html");

 

// create action urls

        PortletURL invokeActionOne = response.createActionURL();

        invokeActionOne.setParameter(ACTION, "1");

 

PortletURL invokeActionTwo = response.createActionURL();

        invokeActionTwo.setParameter(ACTION, "2");

 

PortletURL invokeActionThree = response.createActionURL();

        invokeActionThree.setParameter(ACTION, "3");

 

// generate link

        Writer w = response.getWriter();

        w.write("<a href='" + invokeActionOne.toString() + "'> action 1 
</a>");

        w.write("<br/>");

        w.write("<a href='" + invokeActionTwo.toString() + "'> action 2 
</a>");

        w.write("<br/>");

        w.write("<a href='" + invokeActionThree.toString() + "'> action 
3 </a>");

        w.write("<br/>");

    }

}

 

 

3) PortletB read values of attribute "action" stored by portletA in the 
session (APPLICATION_SCOPE) and executes the corresponding action or the 
method.

 

 

Example of code for portlet B

----------------------------------------------

package jahia.portlet;

 

import javax.portlet.*;

import java.io.Writer;

import java.io.IOException;

 

public class PortletB extends GenericPortlet {

    public static String ACTION = "action";

 

public void doView(RenderRequest request, RenderResponse response) 
throws IOException {

        // first set content type

        response.setContentType("text/html");

       

// get Action

        PortletSession session = request.getPortletSession();

 

// important: get attribute from application scope

        String action = (String) session.getAttribute(ACTION, 
PortletSession.APPLICATION_SCOPE);

        if (action == null) {

            response.getWriter().println("<b> there is no action </b>");

        } else {

            // depending on action value execute a specific method

            if (action.equalsIgnoreCase("1")) {

                response.getWriter().println("<b> Action 1 called </b>");

            } else if (action.equalsIgnoreCase("2")) {

                response.getWriter().println("<b> Action 2 called </b>");

            } else if (action.equalsIgnoreCase("3")) {

                response.getWriter().println("<b> Action 3 called </b>");

            } else {

                response.getWriter().println("<b> Action unknown </b>");

            }

        }

    }

}

 
Order of method execution is the following:
1) processAction(.....) of portletA

2) render(....) (or doView()) of portletA and B. (see page 13 of portlet 
documentation).

The  main ideas are
1) to store shared data between porlets in the session with scope 
"APPLICATION_SCOPE".
2) to portlets have to belongs to same application.


another solution is to user the lib. portlet_messaging:
http://www.doc.ic.ac.uk/~mo197/portlets/portlet_messaging/

I didn't test it but it looks interesting.

Regards,

KT.



[email protected] a écrit :
> Hi,
>
> We're developing a number of applications as Portlets within Jahia. Some of
> these applications provide different functionality for the same data (e.g.
> a Purchase order). We want to be able to link from one Portlet to another,
> providing parameters to load specific details in the linked-to portlet.
>
> e.g. one portlet shows a list of Purchase Orders and we want to link to the
> details of that Purchase Order in another Portlet.
>
> In some cases the Portlets may be on the same page, but more commonly we
> expect the Portlets to be on different pages. As we are developing locally
> and then deploying to a development server and then promoting to QA and
> Production, I'm not sure that the page ids will be consistent between the
> environments.
>
> Is there a syntax for URLs that can be used to link between portlets? Is it
> possible for the request to be an action request, and can we bypass the
> caching? Do you have any recommendation for how we can target portlets on
> different pages if the page ids may vary between environments?
>
> Thanks,
>
> Andrew May
> IT - Sr. Developer
> Abercrombie & Fitch
>
> _______________________________________________
> dev_list mailing list
> [email protected]
> http://lists.jahia.org/cgi-bin/mailman/listinfo/dev_list
>
>   

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