Crude ruby/IRB visualizer tool

ruby_viz.rb

%w[rubygems graphviz rbosa irb].each { |g| require g }

puts "==RubyViz==
For exploring the ruby language, draws a graph of ruby objects as they are instantiated.

Usage:
  declare a top level instance-variable then set attributes one it
  
Example:
  @dog = Object.new
  @dog.name = 'Bess'
  four = 4
  @dog.age = four
  four.description = 'the number four'
  @dog.number_of_legs = 4
  @dog.happiness = 9
  
Bugs / Limitations:
  Too numerous to list here. Graph leaves a lot of deatil to be desired. The main limitation is that only instance variables are followed so Arrays for instance do not visualise well. Cannot be used to visualise any sizable application.

"

# This code - good for experimenting in IRB with, would break most apps:
class Object
  def method_missing method_name, *args
    case method_name.to_s
    when /(.*)=/
      self.instance_variable_set("@#{$1}", args[0])
    when /(.*)/
      self.instance_variable_get("@#{$1}")
    end
  end
end


module RubyViz
  
  def self.plot base_object
    g = GraphViz::new("structs", :type => 'digraph', :path => "/opt/local/bin/")
    
    instances = Hash.new
    nodes = []
  
    create_nodes(base_object, g, instances, nodes)
  
    nodes.each do |n|
      n[:shape] = "Mrecord"
      n[:color] = "lightblue"
    end
    
    g.output(:output => "png", :file => "/tmp/instances.png")
    
    refresh_image
  end
  
  def self.create_nodes parent, g, instances, nodes
    parent_node = g.add_node parent.object_id.to_s
    nodes << parent_node
    parent_label = "{#{parent.class}|#{parent.object_id}|#{parent}|"
    parent.instance_variables.each do |child_name|
      child = parent.instance_variable_get child_name
      child_node = nil
      parent_label << "#{child_name}: #{child.class}\\l"
      if !instances[child.object_id]
        child_node = create_nodes child, g, instances, nodes
        instances[child.object_id] = [child_node, parent_node]
      elsif instances[child.object_id].last != parent_node
        child_node = instances[child.object_id].first
      end
    
      g.add_edge parent_node, child_node if child_node
    
    end
    parent_node[:label] = parent_label+"}"
    parent_node
  end
  
  def self.refresh_image
    current_safari_tab = OSA.app("Safari").windows.first.current_tab
    current_safari_tab.url = current_safari_tab.url
    OSA.app("Safari").open "/tmp/instances.png"
  end
  
end


module IRB
  class Irb
    def output_value_with_ruby_vis
      RubyViz::plot $main
      output_value_without_ruby_vis
    end
    alias_method :output_value_without_ruby_vis, :output_value
    alias_method :output_value, :output_value_with_ruby_vis
  end
end


# start an interactive session
$main = self
IRB.start(__FILE__)

# or visualise a structure based on an object:
# RubyViz.plot object