Misunderstanding : Unable to find component with id 'phl' or A child with id 'phl' already exists:

[andre seame]

Hello,

I try to modify the header of a table. So according to the advice of this 
mailing list, I write


public class DataTableFilterToolbarPage extends WebPage
{

     /**
     * constructor
     */
    public DataTableFilterToolbarPage()
    {
        List<IColumn<Contact, String>> columns = new ArrayList<IColumn<Contact, 
String>>();

        columns.add(new PropertyColumn<Contact, String>(new 
Model<String>("ID"), "id")
        {   private static final long serialVersionUID = 1L;

            @Override
            public Component getHeader(final String componentId)
            {   X1 x = new X1(componentId,"id") ; // My own panel instead of a 
label
                   return x;
            }

        });


As I want to set the sortable link in a part of X1, I modify HeadersToolbar


public <T> HeadersToolbar(final DataTable<T, S> table, final 
ISortStateLocator<S> stateLocator)
    {
        super(table);

        RefreshingView<IColumn<T, S>> headers = new RefreshingView<IColumn<T, 
S>>("headers")
        {
            private static final long serialVersionUID = 1L;

            @Override
            protected Iterator<IModel<IColumn<T, S>>> getItemModels()
            ....

            @Override
            protected void populateItem(Item<IColumn<T, S>> item)

                              {

                if (column.isSortable())
                {
                        header = newSortableHeader("header", 
column.getSortProperty(), stateLocator);
                }
                else
                {
                        header = new WebMarkupContainer("header");
                }

                if (column instanceof IStyledColumn)
                { .... }

                item.add(header);
                item.setRenderBodyOnly(true)
                ((X1)column.getHeader("panel")).ajout() ; // action on X1
                header.add(column.getHeader("panel"));

Where X1 is

public class X1 extends Panel
{
    public X1(String id, String ColumnTilte) //,  TextField<String> x)
    {
        super(id) ;
        lbl = new Label("labelx", ColumnTilte) ;
        add(lbl) ;
    }

    public Label getLabel() { return lbl ; }

    public void ajout()
    {
       add(new Label("phl","added by  headersTools")) ;
    }
}


Run this code, I get

Unexpected RuntimeException

Last cause: Unable to find component with id 'phl' in [X1 [Component id = 
panel]]
        Expected: 
'filterForm:tableWithFilterForm:topToolbars:toolbars:3:headers:1:header:panel:phl'.
        Found with similar names: ''


Markup

The problem is in 
"file:/home/phl/apache-tomcat-7.0.47/webapps/phlwick/WEB-INF/classes/xxx/X1.html":

<wicket:panel xmlns:wicket="http://wicket.apache.org";>
        1<br />

            <span style="color: Blue;">
                <span wicket:id="labelx" id="labelx">The Title of the column 
goes here</span>
            </span>

        <br/>
        <span wicket:id="phl">Action from HeadersTools goes here</span> <br />

</wicket:panel>



I was expecting that the action ((X1)column.getHeader("panel")).ajout() ; will 
define phl in X1


If I change the X.java to


public class X1 extends Panel
{
    public X1(String id, String ColumnTilte) //,  TextField<String> x)
    {
        super(id) ;
        lbl = new Label("labelx", ColumnTilte) ;
        add(lbl) ;
        add(new Label("phl","added by constructor")) ;
    }

    public Label getLabel() { return lbl ; }

    public void ajout()
    {
       add(new Label("phl","added by  headersTools")) ;
    }
}


So I don't understand why the some time the id phl is not declared and sometime 
is it already declared.


This is probably due to the fact that I don't clearly understand the render 
mechanism.


Pointers or ideas are welcome.


Thanks,

PHL.


Then I get :

Last cause: A child with id 'phl' already exists:
[X1 [Component id = panel]]
WicketMessage: Error attaching this container for rendering: [HeadersToolbar 
[Component id = 3]]