samples/scripting.rb

   1 # scripting.rb
   2 # March 30, 2007
   3 #
   4
   5 require 'jruby'
   6
   7 module Scriptable
   8   alias :pre_scripting_method_missing :method_missing
   9
  10   def method_missing(sym, *args, &b)
  11     @engines ||= {}
  12     @engine_manager ||= javax.script.ScriptEngineManager.new(JRuby.runtime.getJRubyClassLoader)
  13
  14     engine = @engines[sym] ||= @engine_manager.getEngineByName(sym.to_s)
  15     if engine
  16       if args.length < 1
  17         raise ArgumentError.new("expected script for argument zero")
  18       end
  19
  20       if args.length >= 1
  21         script = args[0]
  22       end
  23
  24       bindings = engine.createBindings
  25
  26       local_variablator =<<-'LOCAL'
  27       _local_values = {}
  28       local_variables.each do |_local_variable|
  29         _local_values[_local_variable] = eval(_local_variable)
  30       end
  31       _local_values
  32       LOCAL
  33
  34       eval(local_variablator, Binding.of_caller).each_pair {|k,v| bindings.put(k,v) if v}
  35
  36       engine.eval(script, bindings)
  37     else
  38       pre_scripting_method_missing(sym, *args, &b)
  39     end
  40   end
  41
  42   def eval_script(sym, *args)
  43     send sym, *args
  44   end
  45 end