Question

A request scoped bean collects data, from all many other request beans & business logic. This bean is used through the EL expressions in the page but before this request scoped bean may be used in the page, it needs to build a directory using the collected data (This is done after all collection is over but before the bean properties may be used in page).

How can I execute the building of the directory in this bean after all collection but before it is used through the EL expressions in the page without using <f:event>? I need to build it only once.

@ManagedBean(name="namesDirectory")
@RequestScoped
public class NamesDirectory { 

    public void addForPersonNameRetrieval(Integer id) { // this is used to collect the data in bean
           peopleNamesMap.put(id,null);
           .......
    }

    public void buildDirectory(){ // used, when all collection is over, to build the diirectory      
           .......
    }

    public String getPersonName(Integer id) { // used in the JSF page through EL expressions
        name = peopleNamesMap.get(id);
    }

}

Here buildDirectory() needs to be executed at the end of all collection but before using getPersonName() in the JSF page

Answer 1

You have got several options. You could rebuild the directory after every insert or before every retrieval, however this may cause unnecessary rebuilds. You could rebuild the directory only when needed and called:

• Add a flag requiresRebuild and default it to true.
• Set it to true in addForPersonaNameRetrieval.
• Set it to false in buildDirectory.
• Call buildDirectory in getPersonName if a rebuild is necessary.