Creating custom hierarchical data provider

Question

Hi,
I'm trying to create a custom dataprovider for a 3rd party
chart control. As far as I can tell, it works just like any
Flex-provided hierarchical dataprovider control. My problem doesn't
have to do with the control directly, as I haven't yet even tried
to interface my dataprovider with their control (that's why I'm
posting here). I'm having a lot of troubling figuring out how to
implement IHierarchicalData and IHierarchicalCollectionView (or
figuring out what to extend and override to give me the
functionality). The documentation doesn't seem to be detailed
enough to help me .
I can't use a normal XML dataprovider because the XML I have
contains child elements that are data, so I can't just use the
hierarchy of the XML itself. I need to process the XML in some way
using code that actually understands its structure. I intend to
process this into a class that implements IHierarchicalData. The
documentation is really vague on what the results of a call to
getChildren() returns (and how the calling code then breaks the
children apart so it can call getData() on each), but I was able to
figure that out by looking at the source for the chart control I'm
using (it appears to expect an ArrayCollection... why isn't the
IHierarchicalData interface typed as such?). My biggest problem is
understanding the IHierarchicalCollectionView. It has methods to
add and remove child nodes, but I don't see how it's possible for
it to do that. It only has a reference to an IHierarchicalData,
which provides no methods to perform those operations. When I wrap
my IHierarchicalData in the default HierarchicalCollectionView
object (which is just what the chart does, as far as I can tell)
and use methods like addChild(), I get a null reference error, as
mentioned in this stack trace snippet:
Error #1009: Cannot access a property or method of a null
object reference.
at mx.collections::HierarchicalCollectionView/addChild()
I believe I need the HierarchicalCollectionView (or to extend
a class that implements the IHierarchicalCollectionView interface
or implement it myself) because I need to use its functions to
modify my tree structure so that when I change the data, the chart
will update. Is this a correct assumption? If so, how do I use
those functions on the HierarhicalCollectionView? What is it doing
internally? I don't understand how it can be manipulating the tree
in a type-safe manner having only an IHierarchicalData reference to
work with, and if it's doing it in a non-typesafe manner, I need to
know what methods it's calling on my tree or node objects, which
don't appear to be documented in the docs for
IHierarchicalCollectionView.
If I'm totally off-base in the best way to accomplish my
goal, please let me know. I'd also appreciate any information you
could give me, such as info on the hierarchy interfaces that goes
beyond the docs. Some source code for HierarchicalCollectionView
would be super helpful (only for reverse engineering; it should
really be documented somewhere), but I haven't been able to find
any. Isn't it open source?
Thank you very much for any help you can provide.

Answer 1

SAP Note 746227 has addressed this issue. I will close this question.