I've been working on a contribution to maven-dependency-plugin and spent a
fair amount of time trying to figure out how to cleanly implement proper
indentation when converting the dependency tree to json, yaml, etc.
After a bit of pain, okay a lot of pain, I have finally implemented a new
Directive - 'indent' - which extends Block and prepends a 'padding' value
on render(). This works since render() is also called recursively.
(I know there's a TreeContext but I have no idea how to use it, whether it
can be used within the existing plugin, or even if it would help solve this
problem.)
An example of how it is used is:
#macro (writeNodeAsJson $node)
// do the json magic
#end
#macro (walktree $node)
#indent
#writeNodeAsJson($node)
#foreach ($child in $node.children)
#walktree ($node)
#end
#end
#end
(I don't have that code on this system so there may be a slight error in
it.)
At the moment the directive doesn't take any parameter but I do plan to add
an optional one, ideally either a string literal or a reference, but I
haven't coded it yet. In theory it could even be a reference to a different
macro, e.g., so you could have 'I", "II",... then 'a','b'..., then
'1','2'... since the macro could be provided the current indentation depth
but I'll leave that for another day.
I think I have JIRA access and if so I'll create an issue and submit a PR.
Bear Giles
