simple_graphviz_example.rb

require 'graphviz'

# Create a new graph
g = GraphViz.new( :G, :type => :digraph ) 

us_num = 47  #placeholder, will get from file name in final version.  
# set global node options
g.node[:color]    = "#333333"
g.node[:style]    = "filled"
g.node[:shape]    = "box"
g.node[:penwidth] = "1"
g.node[:fontname] = "Trebuchet MS"
g.node[:fontsize] = "8"
g.node[:fillcolor]= "#294b76"
g.node[:fontcolor]= "white"
g.node[:margin]   = "0.0"

# set global edge options
g.edge[:color]    = "#666666"
g.edge[:weight]   = "1"
g.edge[:fontsize] = "6"
g.edge[:fontcolor]= "#444444"
g.edge[:fontname] = "Verdana"
g.edge[:dir]      = "forward" 
g.edge[:arrowhead]="open"
g.edge[:arrowsize]= "0.5"
          
my_nodes={"WF1"=>"New Account Screen", "WF2" =>"Account Recover Screen", "WF3" => "Welcome Screen"}
my_decisions={"D1"=>"", "D2" =>"", "D3" => "", "D4" => ""}

g.add_nodes("Start",{:label => "", :shape => "circle"}) 

my_nodes.each do |key, value|   
  # When adding a node the node name becomes the label so can access later.
  g.add_nodes(key,{:label => value})
end 

my_decisions.each do |key, value|   
  # When adding a node the node name becomes the label so can access later.
  g.add_nodes(key,{:label => value, :shape => "diamond"})
end         
     
g.add_nodes("End",{:label => "", :shape => "circle"}) 
#hello = g.add_nodes( "Hello" )
#world = g.add_nodes( "World" )
puts g.inspect

# Create an edge between the two nodes  
g.add_edges( g.Start, g.D1)  
g.add_edges( g.D1, g.WF1, {:label => "[create account]"}) 
g.add_edges( g.D1, g.WF2, {:label => "[attach account]"}) 
g.add_edges( g.WF1, g.D2) 
g.add_edges( g.D2, g.D3, {:label => "[failure]"})   
g.add_edges( g.D2, g.WF3, {:label => "[account created]"}) 
g.add_edges( g.D3, g.WF2, {:label => "[account exists]"}) 
g.add_edges( g.WF2, g.D4) 
g.add_edges( g.D4, g.WF2, {:label => "[failure]"})
g.add_edges( g.D4, g.End, {:label => "[recovered]"}) 
g.add_edges( g.WF3, g.End)  
# Generate output image
g.output( :png => "US#{us_num}.png" )