Module: Workflow

Defined in:
lib/workflow.rb

Overview

See also README.markdown for documentation

Defined Under Namespace

Modules: ActiveRecordInstanceMethods, RemodelInstanceMethods, WorkflowClassMethods, WorkflowInstanceMethods Classes: Event, NoTransitionAllowed, Specification, State, TransitionHalted, WorkflowDefinitionError, WorkflowError

Class Method Summary collapse

Class Method Details

.create_workflow_diagram(klass, target_dir = '.', graph_options = 'rankdir="LR", size="7,11.6", ratio="fill"') ⇒ Object

Generates a ‘dot` graph of the workflow. Prerequisite: the `dot` binary. (Download from www.graphviz.org/) You can use this method in your own Rakefile like this:

namespace :doc do
  desc "Generate a graph of the workflow."
  task :workflow => :environment do # needs access to the Rails environment
    Workflow::create_workflow_diagram(Order)
  end
end

You can influence the placement of nodes by specifying additional meta information in your states and transition descriptions. You can assign higher ‘doc_weight` value to the typical transitions in your workflow. All other states and transitions will be arranged around that main line. See also `weight` in the graphviz documentation. Example:

state :new do
  event :approve, :transitions_to => :approved, :meta => {:doc_weight => 8}
end

Parameters:

  • klass —

    A class with the Workflow mixin, for which you wish the graphical workflow representation

  • target_dir (String) (defaults to: '.') —

    Directory, where to save the dot and the pdf files

  • graph_options (String) (defaults to: 'rankdir="LR", size="7,11.6", ratio="fill"') —

    You can change graph orientation, size etc. See graphviz documentation



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# File 'lib/workflow.rb', line 338

def self.create_workflow_diagram(klass, target_dir='.', graph_options='rankdir="LR", size="7,11.6", ratio="fill"')
  workflow_name = "#{klass.name.tableize}_workflow".gsub('/', '_')
  fname = File.join(target_dir, "generated_#{workflow_name}")
  File.open("#{fname}.dot", 'w') do |file|
    file.puts %Q|
digraph #{workflow_name} {
graph [#{graph_options}];
node [shape=box];
edge [len=1];
    |

    klass.workflow_spec.states.each do |state_name, state|
      file.puts %Q{  #{state.name} [label="#{state.name}"];}
      state.events.each do |event_name, event|
        meta_info = event.meta
        if meta_info[:doc_weight]
          weight_prop = ", weight=#{meta_info[:doc_weight]}"
        else
          weight_prop = ''
        end
        file.puts %Q{  #{state.name} -> #{event.transitions_to} [label="#{event_name.to_s.humanize}" #{weight_prop}];}
      end
    end
    file.puts "}"
    file.puts
  end
  `dot -Tpdf -o'#{fname}.pdf' '#{fname}.dot'`
  puts "
Please run the following to open the generated file:

open '#{fname}.pdf'

"
end

.included(klass) ⇒ Object 



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# File 'lib/workflow.rb', line 297

def self.included(klass)
  klass.send :include, WorkflowInstanceMethods
  klass.extend WorkflowClassMethods
  if Object.const_defined?(:ActiveRecord)
    if klass < ActiveRecord::Base
      klass.send :include, ActiveRecordInstanceMethods
      klass.before_validation :write_initial_state
    end
  elsif Object.const_defined?(:Remodel)
    if klass < Remodel::Entity
      klass.send :include, RemodelInstanceMethods
    end
  end
end