module ERB::DefMethod

def def_erb_method(methodname, erb_or_fname)

object or eRuby file
define _methodname_ as instance method of current module, using ERB 
def def_erb_method(methodname, erb_or_fname)
  if erb_or_fname.kind_of? String
    fname = erb_or_fname
    erb = ERB.new(File.read(fname))
    erb.def_method(self, methodname, fname)
  else
    erb = erb_or_fname
    erb.def_method(self, methodname, erb.filename || '(ERB)')
  end
end