Seam outjection problem, is this a bug?

[kh2ouija]

Hi.

I have a SFSB Seam component ShowItems which has:

@DataModel
private List<Item> items;

@DataModelSelection
@Out(required = false)
private Item selectedItem;

I display the items with a h:dataTable and when the user clicks on an item he's redirected to a itemDetails page where I have stuff like:

#{selectedItem.name} #{selectedItem.description}

These show blank! as if selectedItem is null. But looking in the debugger I see that in fact it's not.

I added this method on the SFSB:

public String nothing() {
 return null;
}

and put a h:commandLink on the itemDetails page, with action=showItems.nothing. The page shows blank but after clicking on this link (which does nothing other than return to the same page) the selectedItem component is now visible to the page, like it has only now been outjected.


I found a workaround. If I add a getSelectedWebsite() method on the SFSB, then modify the page like this:

#{showItems.selectedItem.name} #{selectedItem.description}

Both name and description appear! It seems the component is outjected only after it is read by the first call to getSelectedItem(). But it doesn't seem right to do.

Does anyone have any idea what's wrong here? Thank you.

[gavin.king]

You have to actually *call* the component for @DataModelSelection and @Out to have any effect.

[kh2ouija]

Thanks for answering me.

Let me get this straight. @Out'd objects only become visible to a new view after a call to the component from that view?

[kh2ouija]

... that is, even if the component has already been used in a previous view? It is a SFSB with Seam session scope.

[gavin.king]

No. Once the object is outjected to the session scope it is visible to all views.

[kh2ouija]

I'm not sure I understand. The component has been used before, when displaying the DataModel. When the user clicks an item in that table, it is set as the selectedItem and the view is changed, but the selectedItem is not visible. It only becomes visible (outjected?) after a do-nothing call to the component from that view, or after referencing it directly from the component with a getter (which only needs to be done one time, as explained in my first post). What am I missing here?

[gavin.king]

I'm not sure what you are missing. This stuff is exactly like the Seam message list example.

Perhaps you are outjecting to the EVENT scope, instead of the SESSION scope.

[kh2ouija]

I have list.jsf which contains the datatable. When the user clicks, an action method is called on the backing component which does nothing else than redirect to detail.jsf - the selectedItem is not visible here.

I changed the method to return null so that it returns to list.jsf - the selectedItem is visible here, yes, like in the messages list example. So this only happens when the view is changed. The component (equivalent of the MessageListBean from the example) has session scope.

case 1) list.jsf -> sfsb.select() -> list.jsf
#{selectedItem} visible

case 2) list.jsf -> sfsb.select() -> detail.jsf
#{selectedItem} not visible

If you say that's the intended behaviour, so be it, sorry for insisting. Thanks.

[gavin.king]

scope of component != scope of outjected object

try Out(scope=SESSION)

are you sure you don't have a <redirect/> in your navigation rule?

[kh2ouija]

Yes, there was a redirect tag there, got rid of it and now it works. I wouldn't have thought of that...

[kh2ouija]

Thanks.