Access grails zkui composer instance of dynamically included view from its parent

I really could use some help here. The scenario is that I am including views within my webapp dynamically depending on user interaction. And the main problem is that i need to access the current instance of the included views composer.

When the user has made some selection and a sub-view is loaded, the user can enter values in the sub-view which i then need to collect to the main view.

Some code fragments that shows somehow what i'm trying to accomplish: (only necessary parts)

grails-app/views/mainview/main.gsp
    ...
    <z:div id="mainContent"></z:div>
    ...

grails-app/views/mainview/templates/one.gsp
    <z:window apply="org.package.composers.OneComposer">
        ...
    </z:window>

grails-app/views/mainview/templates/two.gsp
    <z:window apply="org.package.composers.TwoComposer">
        ...
    </z:window>

grails-app/composers/org/packages/composers/MainComposer.groovy
    Div mainContent
    Composer currentSubComposer = null
    ...
    void setSubContent(String templateURI){
        mainContent.children.clear()
        mainContent << { include(src: templateURI) }
        currentSubComposer = /* HOW TO GET THE COMPOSER INSTANCE ? */
    }
    ...

I know that if you include a sub-view "statically" in your main view without using dynamically using include, Then you can access the sub-composer from the parent as the following code fragment shows:

grails-app/views/common/_subview.gsp
    <z:window id="subview" apply="org.package.composers.SubviewComposer">

grails-app/views/mainview/main.gsp
    ...
    <z:div id="mainContent">
        <g:render template="/common/subview" />
    </z:div>
    ...

grails-app/composers/org/packages/composers/MainComposer.groovy
    Window subview
    Composer c = (Composer)subview.getAttribute("subview#composer")

But i cannot do this as everything is dynamic. I need to be able to do the same thing somehow.

So to break down the basic question:

I have a main composer
In main composer i include a gsp file (sub view)
The sub view has its own composer

How do I access the sub view composer instance from the main composer?

Any help appreciated!

Solution

I'll post my own solution to this, using the grails session, if anyone else is interested. Perhaps there exists other ways of solving this but does the trick:

I created a callback/register method in main composer:

public void registerChildComposer(Composer c){
    currentChildComposer = c
}

and before the sub-view is included in the main composer:

session["parentComposerInstance"] = this

and in doAfterCompose of sub-view composer:

Composer parentComposer = session["parentComposerInstance"]
parentComposer.registerChildComposer(this)

and voila, after this "handshake"-like pattern i got the handle to the sub view composer i was looking for.