EL conditional Method Expression

Question

I would like to declare a conditional method expression in EL like below:

Answer 1

Unfortunately, method expressions does not accept value expressions. Your best bet is to have a single method entry point which in turn delegates further to the desired action methods based on the detailsMode which you also pass/set to the bean.

E.g.

 public void onRowSelect(SelectEvent event) {  
     if ("single".equals(detailsMode)) {
         onRowSingleSelect(event);
     } else {
         onRowUrlSelect(event);
     }
 }

Given that you're actually using a composite component, you can if necessary hide it away in the backing component to reduce boilerplate in backing bean:

...

@FacesComponent("yourComponent")
public class YourComponent extends UINamingContainer {

     public void onRowSelect(SelectEvent event) {  
        String methodName = "single".equals(detailsMode) ? "onRowSingleSelect" : "onRowUrlSelect";
        MethodExpression method = (MethodExpression) getAttributes().get(methodName);
        method.invoke(getFacesContext().getELContext(), new Object[] { event });
     }

}