Conversation binding workaround

[vineetmanohar]

Hi,

Currently I have a seam component "numberGuess" with Conversation.SCOPE. It has a binding that I want to use on the view page directly, but can't because of seam limitation.

@Name("numberGuess")
@Scope(ScopeType.CONVERSATION)
public class NumberGuess implements Serializable {
 private UIInput input;
}

My view is as follows:

<h:inputText binding="#{numberGuess.input}"/>

I realize that conversation scoped components cannot be accessed through "binding" from the view, as discussed in the following posts:
http://www.jboss.com/index.html?module=bb&op=viewtopic&t=97544
http://www.jboss.com/index.html?module=bb&op=viewtopic&t=99270
http://www.jboss.com/index.html?module=bb&op=viewtopic&t=97182

As a workaround the posts suggest that "Just do you bindings on an event scoped object and inject that object in."

I am new to seam and would appreciate if someone could explain a bit more specifically how to accomplish the above. Do I need to create a new seam component with EVENT scope?

Thanks in advance!

[pmuir]

Exactly.

@Name("binding")
@Scope(EVENT)
public class Binding {
// Do your binding here
}

@Name("numberGuess")
@Scope(ScopeType.CONVERSATION)
public class NumberGuess implements Serializable {

 @In Binding binding

 // Do work on the binding in your method

}

[vineetmanohar]

Thanks for you reply, that was very helpful.

So suppose I created a seam component called "binding" with EVENT scope as you have suggested, how can I initialize it? I want to set the value of this component from my Conversation component "numberGuess".

Can I @Out-ject the value from Conversation to Event scope?

[pmuir]

Yes

@Name("numberGuess")
@Scope(ScopeType.CONVERSATION)
public class NumberGuess implements Serializable {

 @In(create=true) @Out Binding binding;

 @Create
 public void createBinding() {
 binding.setFoo("bar");
 }

 // Do work on the binding in your method

}

[vineetmanohar]

Thanks again for the reply. I tried exactly what you said and ran into a problem.

binding="#{binding.myBean.myComponent}": Target Unreachable, 'myBean' returned null

I debugged and found that my @Create method in NumberGuess was not called yet. Therefore the @Out-jection did not occur yet. It seems that when I access the numberGuess.xhtml page, the bindings are first resolved on the xhtml page first, and then the conversation is started which and that is when my @Create method is called.

I start the conversation by typing the /numberGuess.xhtml url in the browser. I have the following entry in my pages.xml

<page view-id="/numberGuess.xhtml">
 <begin-conversation join="true" pageflow="numberGuess"/>
 </page>

How can I first start my conversation and then redirect to the view? How can I start a conversation by typing a URL but using start-state, instead of start-page?