[Zope] keeping state of tree over different documents

[Dieter Maurer]

Marcus Schopen writes:
 > The problem that occurs is, that the tree`s open/close state is not correctly maintained over the different documents. A solution to that might be to append the state of the tree after selection of a link to the it's URL as ?tree-s=.... ; that means pass the future state of the tree to the selected page by using URL-Parameters.
 > 
 > Any ideas how to do that or any other ideas?
I think, this is a great idea!
It would avoid the cookie to save the state and
would therefore be much more robust.

I have extended the TreeTag to allow explicite control 
of the hotspot (i.e. the icon to control opening/closing
a branch). The extension is not yet general enough to
support passing the future state (after the operation)
but still uses the incremental state change.
The extension is not easy to understand and packaged
with our changes to the TreeTag.

There may be another way to influence the hotspot as
Zope magically adds a "target" in the left frame
of its management screen. I did not yet look at
how it works.

You find the function to compute the new state in
"TreeDisplay.TreeTag.apply_diff".



Dieter