Hello,

In velocity for now, we can't use the '$macro.myVar' to retrieve the result of a child macro. Because of this limitation we must use a global variable (which as a risk of conflict with an other part of code which use the same variable.

Let's take an example:

#macro(myChildMacro $return)
  #set($return = $NULL)
  #setVariable("$return" "my new value")
#end

#macro(myParentMacro)
  #myChildMacro($macro.childResult)
  $macro.childResult
#end

#myParentMacro()

This code won't work, so we have this result

$macro.childResult

This is because we call 'myChildMacro' with the variable '$macro.childResult'. To make it working, instead we must use a global variable like '$childResult' which is in the global context.