Antwort: Re: Re: Re: [tree2] Problems with new TreeModel interface (need help!)

[mathias . werlitz]

[EMAIL PROTECTED] schrieb am 10.08.2005 00:06:08:

> @Mathias,
>
> Looks good.  I made a few tweaks (mostly formatting changes) and
> committed.  I also changed the examples back the way they were before
> the model change.

I'm glad that its working :) It was more a proof of concept than a final
implementation.

>
> I like your idea of optionally persisting the TreeState.  At some
> point, I may want to update one of the simple examples and have this
> point to a bean with session scope so we can show users how this
> option works.

I hope this gives us more flexibility concerning the tree state and
still supports the old behaviour.

>
> The expandAll problem is an interesting one.  What do you think about
> the TreeState having a ref to the model?  This would seem to be
> necessary if you wanted to update the state through the TreeState
> class.  Another possibility is moving this method back to TreeModel
> which could iterrate through the list of all nodes, and call
> toggleExpanded on the  TreeState.  I kind of prefer this approach as
> it leaves the two decoupled.

This problem is a bit tricky. Somehow the two (model and state) are closly related,
as the state is specific for a given model but we want to decouple it.

My opinion is that the state should NOT have a object reference to the model.
Saving it with the tree state would include saving the model along. That would be bad.
Okay we could make this poperty transient or implement a custom serialization?!

We could provide the model in the expandAll method so its only a local referece.
That should work.

Putting back the method to the model is a good idea, although the function is really related to the model
- more to the state.


Well this a a more general problem, because we have two different ways of referencing a node and the model has to mediate between these two.
At the moment it does this only one way ("nodepath" or nodeid -> TreeNode). As I understand the code the way from TreeNode to "nodepath" is put at different places also in the renderer.

I saw that you closed the MYFACES-361. There is a relation to this problem regarding the TreeModel.