How to get a form parameter and refresh the web web page itself?

Question

I thought its easy as a piece of cake. But what I found out is that somehow it is getting the parameter after the web page is refreshed!
Any advice is greatly appreciated. Thanks!
for navigation method
   //navigation method
    public Object refresh()
        return Navigation.HOME;
    }for web page
<h:commandLink value="Regenerate resutls"  action="#{bean.refresh}">
                   <f:param name="algorithm" value="#{HomeMBean.algorithm}"/>
                </h:commandLink>

Answer 1

What I am trying to say here is:
for a web page, I want to refresh the web page based on a parameter chosen by users,
In web page:
<h:commandLink value="Regenerate resutls"  action="#{bean.refresh}">
            <f:param name="algorithm" value="#{HomeMBean.algorithm}"/>
</h:commandLink>in managed bean:
    //navigation method
    public Object refresh()
        return Navigation.HOME;
    }also in managed bean:
String algorithm = FacesContext.getCurrentInstance().
getExternalContext().getRequestParameterMap().get("algorithm");
        logger.debug("parameter="+algorithm);What I observed is I will never get the parameter "algorithm" before the web page is refreshed. In other words, the method setAlgorithm() is always called after the web page is rendered.
I in fact want to render the web page based on the parameter "algorithm".
I spent quite a lot time on it but can't figure out why.
My guess is for managed beans, I can't rely on one property to generate another property, is that right?
How should I solve this problem? Thanks a million!