JSF composite does not store state with StateHelper

Question

I am developing a JSF composite that gets a complex data structure as argument:

<cc:interface componentType="MyComponent">
    <cc:attribute name="myModel"    required="true"     type="my.package.Model" />
</cc:interface>

The backing component processes this model using an init() method that is invoked in the composite via an event:

    <cc:implementation>
        <f:event type="postAddToView" listener="#{cc.init}" />
        [...]
    </cc:implementation>

In this init() method I check if the model has already been processed (because I don't want to do that every time the user stays on the page, eg through ajax requests). Hence I store the processed model via StateHelper.put():

public void init() 
{
    if (getMyModel() == null)
    {
        MyModel model = processModel(...);
        setMyModel(model);
    }
}

@SuppressWarnings("unchecked")
public MyModel getMyModel()
{
    return (MyModel) getStateHelper().get("MyModel");
}

public void setMyModel(MyModel MyModel)
{
    getStateHelper().put("MyModel", MyModel);
}

I expect now, that if the init() method is invoked for example during an Ajax request (in the same view scope) it does not process the model a second time because I have stored it in the view scope via the StateHelper. But no matter what I try, if I click on a command link with void/null outcome the getMyModel() method always returns null. Any ideas?

Answer 1

Implementing the restoreState() method in the backing component and setting a breakpoint revealed the problem. The postAddToView event is processed before the invocation of restoreState() . Using preRenderView instead resolved the issue for me.