The basic problem with modeling a treeview after a nested JSON datastructure is this:
How do you store the treeview-specific settings (such as which treenodes are folded open at any time) while not mangling the original JSON nested datastructure that populates the treeview in the first place?
None of the free javascript treeview components I checked out for usage in seductiveapps do this (yet, at time of creating this component).
The answer is : you store the treeview-specific settings seperately from the original datastructure, and have the javascript treeview component serve as a liason between the two datastructures (to the point of automatically saving both the original datastructure and the treeview-instance-specific settings whenever needed).
So, onto the next question : where do you store the treeview-specific settings?
In window.top, to provide not only a single point of storage for all treeview-specific settings, but to potentially let these settings be used throughout an entire site.