Module: Workflow

Defined in:
lib/workflow.rb,
lib/workflow/transactional.rb,
lib/workflow/mongoid_persistence.rb,
lib/workflow/remodel_persistence.rb,
lib/workflow/active_model_persistence.rb,
lib/workflow/state_dependent_validations.rb

Overview

Provides transaction rollback on halt. For now, you can choose between normal halt without any change to ordinary persistence (halt) or halt with transaction rollback (halt_with_rollback!), which will raise an ActiveRecord::Rollback exception. So this only works with ActiveRecord atm.

Defined Under Namespace

Modules: ActiveModelPersistence, MongoidPersistence, RemodelPersistence, StateDependentValidations, Transactional, WorkflowClassMethods, WorkflowInstanceMethods Classes: Event, NoTransitionAllowed, Specification, State, TransitionHalted, WorkflowDefinitionError, WorkflowError

Class Method Summary collapse

Instance 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 409

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 klass.new.workflow_diagram(graph_options)
  end
  `dot -Tpdf -o'#{fname}.pdf' '#{fname}.dot'`
  puts "A PDF file was generated at '#{fname}.pdf'"
end

.included(klass) ⇒ Object 



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# File 'lib/workflow.rb', line 370

def self.included(klass)
  klass.send :include, WorkflowInstanceMethods
  klass.extend WorkflowClassMethods

#     [ActiveModelPersistence, MongoidPersistence, RemodelPersistence].each do |konst|
#       if konst.happy_to_be_included_in? klass
#       raise "including #{konst}"
#         raise "including #{konst}"
#         klass.send :include, konst
#       end
#     end
end

Instance Method Details

#workflow_diagram(graph_options) ⇒ Object

Returns a representation of the state diagram for the calling model as a string in dot language. See Workflow.create_workflow_diagram for more deails



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# File 'lib/workflow.rb', line 422

def workflow_diagram(graph_options)
  str = <<-EOS
digraph #{self.class} {
graph [#{graph_options}];
node [shape=box];
edge [len=1];
  EOS

  self.class.workflow_spec.states.each do |state_name, state|
    state_meta = state.meta
    if state == self.class.workflow_spec.initial_state
      str << %Q{  #{state.name} [label="#{state.name}", shape=circle];\n}
    else
      str << %Q{  #{state.name} [label="#{state.name}", shape=#{state_meta[:terminal] ? 'doublecircle' : 'box, style=rounded'}];\n}
    end
    state.events.each do |event_name, event|
      event_meta = event.meta
      event_meta[:doc_weight] = 6 if event_meta[:main_path]
      if event_meta[:doc_weight]
        weight_prop = ", weight=#{event_meta[:doc_weight]}, penwidth=#{event_meta[:doc_weight] / 2 || 0.0}\n"
      else
        weight_prop = ''
      end
      str << %Q{  #{state.name} -> #{event.transitions_to} [label="#{event_name.to_s.humanize}" #{weight_prop}];\n}
    end
  end
  str << "}\n"
  return str
end