Why does backbean's method be invoked when page navigation to other page

Question

Hi, All
Why does backbean's method getBeans() be invoked
when current page(list.jsp) navigation to other page(edit.jsp)?
//client list.jsp
<h:dataTable id="items" value="#{userDelegate.beans}"
var="user" rowClasses="oddRow, evenRow" headerClass="tableHeader" >
//server backbean
public class CustomDelegate extends BaseDelegate{
public ListDataModel getBeans(){}
when list.jsp first initialize(first load), jsf invoke getBeans(), is right;
but when from list.jsp navigation to edit.jsp, jsf invoke getBeans() too!
what's the matter with it?

Answer 1

How are you invoking the navigation? With a simple h:outputLink which links to another page or with an h:commandLink/h:commandButton which naturally first invokes the backingbean?
If you're using h:outputLink, then this behaviour may not occur. You may review/redesign your JSF and bean logic.
If you're using UICommand link/button, then this is usual behaviour. (re)read the JSF lifecycle for an explanation. If you ONLY want to get the navigation case, then you can 1) replace the methodbinding from action or actionListener by just the navigation case string, or 2) add immediate="true" to the UICommand element.
This article might be of interest: http://balusc.xs4all.nl/srv/dev-jep-djl.html