workflow engine ruby version

gistfile1.rb

class WfEntry < ActiveRecord::Base
  has_many :history_steps, :foreign_key => :entry_id, :class_name => 'WfHistoryStep', :dependent => :destroy
  has_many :current_steps, :foreign_key => :entry_id, :class_name => 'WfCurrentStep', :dependent => :destroy
  has_many :comments, :as => :container, :dependent => :destroy
  belongs_to :document, :polymorphic => true
  
  named_scope :todo_of_workflow_name_and_owner, lambda { |workflow_name, owner_name|
    {:include => :current_steps,
     :conditions =>["name = ? and #{WfCurrentStep.table_name}.owner = ?", workflow_name, owner_name ]}
  }

  named_scope :draft_of_workflow_name_and_owner, lambda { |workflow_name|
    {:include => :current_steps,
     :conditions =>["name = ? and #{WfCurrentStep.table_name}.previous_id is ?", workflow_name, nil ]}
  }

  named_scope :draft_of_workflow_name_and_owner, lambda { |workflow_name|
    {:include => :current_steps,
     :conditions =>["name = ? and #{WfCurrentStep.table_name}.previous_id is ?", workflow_name, nil ]}
  }
  
  named_scope :in_process_of_workflow_name_and_owner, lambda { |workflow_name|
    {:include => :current_steps,
     :conditions =>["name = ? and #{WfCurrentStep.table_name}.step_id <> ? and  #{WfCurrentStep.table_name}.step_id <> ? ", workflow_name, "900", "100" ]}
  }
  
  named_scope :completed_of_workflow_name_and_owner, lambda { |workflow_name|
    {:include => :current_steps,
     :conditions =>["name = ? and #{WfCurrentStep.table_name}.step_id = ?", workflow_name, "900" ]}
  }
  
  named_scope :all_of_workflow_name_and_owner, lambda { |workflow_name|
    {:include => :current_steps,
     :conditions =>["name = ? ", workflow_name ]}
  }
  
  named_scope :rejected_of_workflow_name_and_owner, lambda { |workflow_name|
    {:include => :current_steps,
     :conditions =>["name = ? and #{WfCurrentStep.table_name}.step_id = ?", workflow_name, "800" ]}
  }
  
  named_scope :document_with_text, lambda { |text|
    {:include => :current_steps,
     :conditions =>["exists(select document_id from full_texts where full_texts.document_type = wf_entries.document_type and full_texts.document_id = wf_entries.document_id and full_texts.full_text like ?)", "%#{text}%" ]}
  }
  
  def temp_comment
      comments.find_by_comment_key("temp") || comments.create(:comment_key => "temp")
  end
  
  def subject
    'The subject of the document'
  end
  
  def initialize_workflow(action_id, params = {})
    wf = eval(name).new
    action = wf.initial_actions.find { |a| a[:action_id] == action_id }
    transition_workflow(action, params)
  end
  
  def do_action(action_id, params = { })
    action_id = action_id.to_sym
    action = config.steps["S#{current_steps[0].step_id}".to_sym][:actions][action_id]
    if action[:before_action_script] 
      return false unless eval(action[:before_action_script])
    end
    
    transition_workflow(action, params)
    
    eval(action[:post_action_script]) if action[:post_action_script]
    
    # record comment
    if params[:comment]
      params[:comment][:author] = User.current.login
      comments.create(params[:comment])
      temp_comment.destroy
    end

    return true
  end
        
  def transition_workflow(action, params = { })
    old_step = self.current_steps.length > 0 ? self.current_steps[0]: nil
    history_step = self.history_steps.create!(:entry => self, 
                               :step_id => old_step.step_id, 
                               :owner =>  old_step.owner,
                               :caller => User.current.login,
                               :action_id => action[:action_id].to_s[1..3].to_i,
                               :start_date => old_step.start_date,
                               :finish_date => Time.now) if old_step
    current_step = self.current_steps.create(:entry => self, 
                              :step_id => action[:to_step_id].to_s[1..10].to_i, 
                              :owner => eval(action[:owner]),
                              :start_date => Time.now)
    current_step.previous = history_step if history_step
    current_step.due_date =  current_step.step_def[:due_days].to_i.days.from_now if  current_step.step_def[:due_days]
    current_step.save!
    self.current_steps.delete(old_step) if old_step
  end
  
  def config
    @wf_config ||= eval(name).new
  end
  
  def current_step
    return current_steps[0] if current_steps.length > 0
    nil
  end
  
  def available_actions(username, parameters = { })
    step = current_step
    return [] unless is_current_step_owner(username)
    
    step_id = step.step_id
    config.steps["S#{step_id.to_s.rjust(3, '0')}".to_sym][:actions]
  end
  
  def is_document_owner(username)
    return false if current_step[:owner].blank? 
    if  history_steps.blank?
      return true
      else
      return history_steps.first.owner.grep(/#{username}/).length > 0
    end
   end

   def is_current_step_owner(username)
    return false if current_step[:owner].blank? 
    current_step[:owner].grep(/#{username}/).length > 0
  end

   def is_editable(username)
    is_document_owner(username) &&  is_current_step_owner(username)
   end
  
  def current_comment_key
    config.steps["S#{current_step.step_id}".to_sym][:comment_key]
  end
end