XPages Extension Library
In the Documentation for the 8.5.2 version you can read "The content of the dialog is defined as any other XPages content, and can access the current context." Anyway I´m not able to access any scoped variables or the compositeData. My fault or a bug?
The dialog content can access any data made available byt its parent node. This is demonstrated in the sample DB. I would belive that it is something in your code.
I wanted to use event compositeData is allways null. But it is no problem to access scoped variables, though I used that as a workaround. Still it would be nice to have compositeData available.
The properties are not yet available before the content is created. There is no simple implementation in core to make this happen.