Message: 5
Date: Thu, 2 Apr 2009 10:53:04 +0200
From: Rong Chen <rong.acode@gmail.com>
Subject: Re: Question about the item property of Item_Tree
To: For openEHR technical discussions <openehr-technical@openehr.org>
Message-ID:
<ebd0d070904020153y4bac0b48yb794a8b7fa2885d8@mail.gmail.com>
Content-Type: text/plain; charset=ISO-8859-1Hi Seref,
Interesting thought! I think this comes down to a design choice, which
is whether we want to force single-rooted tree. By definition, tree
data structure has a single root. But when we model hierarchical
structure of clinical content, it's convenient to allow multiple nodes
at the top level of the tree without the need to create a root node
just to satisfy the notion of single-rooted tree. So it's a choice
between purity (according to computer science definition of a tree)
and convenience (which somewhat indirectly translated to usability of
the model and relevant tools).Cheers,
Rong
Not sure if it helps in the design but in Java (Swing) the JTree
control's model has a tree data structure (per comp sci definition)
but to display a multiple top level nodes you can mark the root node
as hidden.