Yep, I pretty much got that the mxml was for the display, and the AS for the processing. I was just kinda hoping there was a way to do the inclusion, but I may have to just create some custom components instead.
Thats ok no worries.
As for graphs, they are an abstract data structure, hold on I'll get a link to them:
Here we go, this information pretty much sums up the graph:
Very handy to use, fairly easy to program and many many uses available. Unfortunately they are not predefined in PHP either (to my knowledge anyway :P). Check it out, definitely worth knowing how to use!
Oh yeah duh, you wanted to know more on the data too :P
The system I'm working on is a tagging system for media. The tags are grouped and controlled by child / parent relationships, hence the usage of the flex tree for display - its a perfect choice.