复合组件递归传递支持bean

Question

I everyone i'm trying to make a recursive menu using composite components but i cant figure out how to pass a backingbean in to the same composite component well mi code looks like this

<composite:interface>
     <composite:attribute name="bean" required="true"/>
     <composite:attribute name="node" required="true"/>
</composite:interface>

<cc:implementation>
     <--some code here-->

     <c:if test="#{not empty cc.attrs.bean.obtainsubmenu(cc.attrs.node)}">
          <c:foreach items="cc.attrs.bean.obtainsubmenu(cc.attrs.node)" var="submenu">
               <!--some other code here-->
               <menu:recursivemenu
                   bean="#{cc.attrs.bean}"
                   node="#{submenu.idOpc}"
               />
          </c:foreach>    
     </c:if>
</cc:implementation>

the method obtainsubmenu only returns a list of objects the method looks something like this

public List<myObject> obtainsubmenu(Long id){
 return mymap.get(id); //where my maps is parametized  this way Map<Long, List<MyObject>
}

For the first level of my menu it looks to work just fine the problem is when it tries to call itself to do the recursive it is not pasing the object reference as it should and i'm getting an stackoverflow exception cause because the map is null

is there a way to do this??

Tanks for the help!!

Answer 1

first of all, you shouldn't use JSTL tags, but JSF ones.

empty-check should not be necessary, either

<composite:interface>
     <composite:attribute name="bean" required="true"/>
     <composite:attribute name="node" required="true"/>
</composite:interface>

<cc:implementation>
     <--some code here-->

    <ui:repeat value="#{cc.attrs.bean.obtainsubmenu(cc.attrs.node)}" var="submenu">
        <!--some other code here-->
        <menu:recursivemenu bean="#{cc.attrs.bean}" node="#{submenu.idOpc}"/>
    </ui:repeat>    
</cc:implementation>

however, if you are creating a Primefaces menu, this approach will not work. you have to build your programmatic menu inside a MenuModel

more generally, if your menu root component is responsible for rendering its child components itself ( menuComponent.getRendersChildren() returns true ) this kind of approach will not work.