Hi,
We really like your idea. Unfortunatly, there is no other option today.
However, we've built a beta version that does not remove extra heading spaces.
https://dl.dropboxusercontent.com/u/13064071/plantuml.jar
With this beta, you can simply have:
@startuml
class Foo{
**Bar(Model)**
|_ prop
|_ **Bom(Model)**
|_ prop2
|_ prop3
|_ prop3.1
|_ prop4 :(
--
}
@enduml
And we will add this new syntax in the creole parser, so that |_ could be renderer as a real tree.
Thanks for the suggestion : we will post a message here when this will be ready.