complex_substitutions.rb

require 'rubygems'
require 'ruote'

# preparing the engine

engine = Ruote::Engine.new(
  Ruote::Worker.new(
    Ruote::HashStorage.new))

pdef = Ruote.process_definition :name => 'test' do
  # literal output
  echo 'test'
  # top-level variable
  echo '${foo}'
  # or use f: prefix
  echo '${f:foo}'
  # variable in a hash?
  echo '${f:foo_hash["key"]}'
end

# launching, creating a process instance

wfid = engine.launch(pdef,
  'foo' => 'bar',
  'foo_hash' => {'key' => 'value'})
engine.wait_for(wfid)