Subject Re: [IBO] treeview components
Author Andreas Hesse
Hello Gediminas,

for VT you have to define and fill the data-structure for any node in
the tree.
If you want to show the a tree from one table (or view) you can use
IBO_VT, because it has already defined a data-structure to support
self-realtionsphip to a parent field. But it is only suitable for
small/medium ResultSet sizes, because it uses a fetchall to fill the nodes.

If you want to show data from different tables in for example every
node level, you must define your own data-structure.
Look at the examples for Virtuall Tree View ( and
play with them.
If you find a solution, make it public to the community, so that others
can learn from it.


Gediminas schrieb:

>VT is a great component, but that's why I have hesitation:
>VT data providing leaves on the application - as it doesn't know nothing
>about data. Now, if there is DB dataset with the data, application is
>responsible to provide then to the VT( OnGetText & other VT events). So,
>this component isn't data aware, as data aware components would know, how
>to display/work with a data (VT uses higher level data abstraction). So if
>VT is supposed to work with the IBO, it needs wrapper (wrapping level),
>which would handle data provision in both ways. Such level must work
>efficiently, otherwise it would be the bottleneck to work with great data
>I guess, that
>by Andreas Hesse & others is such wrapper. Problem is, that I can't use as
>I use BCB6 - could anyone help me with this?
>Maybe Andreas Hesse & others could contack me - there is missing the e-mail
>address :-/
>Helen, it would be great to hear your oppinion on this topic. Besides, I
>almost sure, that IB_TreeView component would be great IBO addition
>(somewhere see Jason's/Helen's answer: "Any voluteers?" :-) )
>These are only my thoughts, so they could be totally wrong - never before
>used DB aware treeview component, so this is a new field for me
>At 2004-03-23 17:46, you wrote:
>>The turning point for me was a demo I got that allows almost any db to be
>>read, by
>>almost any IB/FB component set you'd want to use. Created by a VST user,
>>Slurink, see In that demo he uses, IBX
>>but they are easily switched out to IBO components. This particular demo
>>does almost
>>exactly what you're asking for.
>>Unlike some of the other solutions, this is a couple of .pas files, not a