Can you show us how you mapped activeLanguage?

This looks like a bug to me.  Unless you hear differently from a Seam developer, I think you should create a jira issue.  Also, if possible, it'd be helpful if you'd create a simple SeamTest that reproduces this.

You don't have a name or scope for XLanguage.....

XLanguage shouldn't need a @Name or @Scope.  The variable in question (activeLanguage) is provided by a @Factory.  (It just so happens that the factory resides in this component, instead of somewhere else.)

Sorry I meant activeLanguage, and Factory doesn't create anything if I remember correctly.  It just runs when that particular member variable is called. You still need to map active language.  ;)

Actually, thinking about it a little further, I don't think this is doable.  I don't think Seam's injection could support that type of cylic dependency.  In this case, I think the best thing Seam can do is throw an exception, instead of behaving oddly as you are seeing.

Oh sorry, but what I was saying is XTextSessionWrapper is mapped to a session scope with the variable 'xtw' which is great.  You do have this:

    @In(required=false, create=true)
    @Out
    private XLanguage activeLanguage;

But you must have a activeLanguage mapped somewhere in your app.  So either in your XLanguage you must have:

@Name("activeLanguage")
@Scope(ScopeType.SESSION)
public class XLanguage { ... }

or you have it mapped in your components.xml file

<component name="activeLanguage" class="com.foo.XLanguage">
   <property name="someProperty">foo</property>
</component>

Otherwise you will receive the null value.

Matt I think you are correct and this sort of cyclic dependency doesn't work, but I agree there is something a bit odd going on here.

Bogodan, could you attach a runnable example, or a patch against one of the examples so we can see the problem locally and make sure we fix the correct one.

Bogdan, did you solve your problem already?

I encountered a problem like this also, but I tried to do the same thing with a simple String value. It works for me now, but I can't really recall how I solved the problem because I simply tried too many things!

Anyways, I can see different things which can cause the problems here. You're calling the getText()-method you say right? So Seam should be doing this since your bean is bijection-enabled:

1. bijecting fields if any getter() method is called


2. bijecting fields if the getText()-method is called


3. bijecting fields if the Factory method is called

How do refer to the activeLanguage property? Are you calling '#{activeLanguage}' or are you calling '#{xtw.activeLanguage}'? The second way effectively uses the getter()-method and therefore triggers bijection. In that case it might be that the activeLanguage property was not created and you get the 'cannot outject a null value'.

So what you have to do is set the @Out to @Out(required=false) since it can be that Seam is having the just described status of the activeLanguage property. This should be enough to remove the error message.

But there is some more. Seam should create this instance with the help of the factory you declared, so you should not need the create=true on the @In annotation. The autocreate=true attribute should also only be necessary if you're not accessing the property with e.g. an EL-expression and you want to have it created anyways...

I hope I'm telling you the right stuff here, so it would be nice if others could confirm what I just mentioned here. I also had this problems and somehow it works for me now. Unfortunately I can't really recall why it didn't work anymore, but above explanation makes sense to me...

I have one more thing. If I set the @In annotation to @In(create=true), then my factory gets called 3 times, but I'm really requesting the property only once. The only difference from before is the create attribute set to true instead of nothing and causes such a weird factory call. I had situations where the factory was called even several times. But this might have been because of the outjection problem with the null value and this is solved now for me.

Does anyone have an answer for the reason that the factory is called 3 times instead of only once when I set the create attribute of the @In annotation to true?

Well....maybe I could give a hint with that...

Frank