Thursday, 20 March 2008

Oracle ADF Two action listeners in one action

Some time ago, I run into a situation when I wanted to add two action listeners inside a single command element but I realized that this was just not possible. When I asked about that in the JDeveloper forums somebody told me that this could only be accomplished in code, but at that time my knowledge was just not enough

A couple of days ago I run into the same problem. I had a view page that when accessed wanted to know two things:

  • First was the ${row.rowKeyStr} of the row to display and ...
  • Next a session scope boolean parameter called #{sessionScope.returnHome} that indicated whether to return the user to the application home page or to another (the search in that case) page.

To summarize, I ended up with the a button called View record in two different pages both having a navigation case (also called view) linking to the view record page. in the application JSF diagram.

On both cases the expression #{row.rowKeyStr} had to be recorded in the JSF session scope along with a value for the returnHome flag that had to be true on one occasion and false on the other..

Following is the code I used to perform this. First the base class :

package myapp.view.backing;

import javax.faces.application.Application;
import javax.faces.context.FacesContext;
import javax.faces.el.ValueBinding;

class backing_SRListBase {

    public backing_SRListBase()
    public String viewButtonBase_action( boolean returnHome)
        // access the faces context
        FacesContext fc = FacesContext.getCurrentInstance();
        Application app = fc.getApplication();
        // on both case row.rowKeyStr points to the current row key
        ValueBinding vbActRowKey = app.createValueBinding("#{row.rowKeyStr}");
        String rowKey = (String )vbActRowKey.getValue(fc);
        // in that case we must save that in sessionScope
        ValueBinding vbSessionScopeRowKey = app.createValueBinding("#{sessionScope.rowKey}");
        vbSessionScopeRowKey.setValue( fc, rowKey);
        // also save the return home boolean value
        ValueBinding vbReturnHome = app.createValueBinding("#{sessionScope.returnHome}");
        vbReturnHome.setValue( fc, new Boolean( returnHome));
        return "view";

Finally, the backing bean for each of the two pages looks like this

package myapp.view.backing;

public class backing_OpenSRList 
    extends backing_SRListBase {

    public backing_OpenSRList()

    public String viewButton_action()
        return viewButtonBase_action( false);

Friday, 7 March 2008

Firefox on CentOS 5.1

Thanks to people like Diezel who posted the original article on, we now know that in order for Firefox 2.0 to run on a CentOS (or Red Hat EL) version 5.1 machine, we need to install compat-libstdc++-33.

Using yum this is done as easy as entering

#yum install compat-libstdc++-33

s the root user. The rest is trivial.