Hi all, I want to filter my refile targets to "Tasks" headings.  This snippet works:

There's a few things I'd like to improve on:

1) My org-agenda-files show up in the list.  For example, foo.org and bar.org show up in the refile targets, despite the function should return nil if a heading does not contain "Tasks"

2) I would like to limit the "Task" headings to those that have a parent heading with a tag :project:

I have :project: tag as exclude-from-inheritance, so this might be tricky

3) I would like the parent heading with :project: tag to have a TODO state that is not "done" and is not "cancelled".

Can anyone help me improve on this?  I think I'm missing some really easy documentation / examples.  As an aside, is there a definitive "Org Mode API" doc that shows the functions that would assist me in writing a function to perform the above filtering?  Something like a Javadoc for Org-Mode?  There's great articles, etc. but I think it would be cool to have a "public" API defined / documented - otherwise it seems that I'm simply going through existing blogs, documentation etc and of course the source code.  When going through source code, there's many functions that are named similarly and yes there's docs but I found myself wanting some kind of Javadoc-ish API documentation :)

Thanks,

--Nate