Class: Ruote::Exp::WaitForEventExpression

Inherits:
AwaitExpression
  • Object
show all
Defined in:
lib/bumbleworks/ruote/exp/wait_for_event_expression.rb

Instance Method Summary collapse

Instance Method Details

#apply ⇒ Object

This does the same as the base AwaitExpression#apply, except that this will always be a global listener, listening for a ‘left_tag’ event, and the event’s workitem will be discarded after the reply is complete. The event’s workitem is only used for comparisons in the where clause (see #reply).



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# File 'lib/bumbleworks/ruote/exp/wait_for_event_expression.rb', line 13

def apply
  update_tree
  h.updated_tree[1]['global'] = true
  h.updated_tree[1]['left_tag'] = attribute_text.to_s
  h.updated_tree[1]['merge'] = 'drop'
  super
end

#reply(workitem) ⇒ Object

On apply, the workitem for this FlowExpression was replaced by the workitem from the event. So when we refer to “f:” in this #reply method, we’re looking at the event’s workitem, which will be discarded at the end of this reply (and replaced with the applied workitem). In order to compare the event’s workitem with the applied workitem (so we can determine whether or not the event was intended for us), we assign the applied_workitem’s fields to a hash on the event’s workitem fields, available at “f:receiver.*”.



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# File 'lib/bumbleworks/ruote/exp/wait_for_event_expression.rb', line 28

def reply(workitem)
  update_tree
  # If we have a where clause at all...
  if translated_where = attribute(:where, nil, :escape => true)
    if translated_where.to_s == 'entities_match'
      # Check to see that the event's entity is equal to the current workitem's
      # entity.  If so, this message is intended for us.
      translated_where = '${"f:entity_id} == ${"f:receiver.entity_id} && ${"f:entity_type} == ${"f:receiver.entity_type}'
    else
      # This just gives us a shortcut so the process definition reads more
      # clearly.  You could always use "${f:" and "${f:receiver." in your
      # where clauses, but you have to remember that the former refers to the
      # incoming event's workitem, and the latter is the workitem of the
      # listening process.
      translated_where.gsub!(/\$\{(['"]?)event:/, '${\1f:') # event workitem
      translated_where.gsub!(/\$\{(['"]?)this:/, '${\1f:receiver.') # listening workitem
    end
    h.updated_tree[1]['where'] = translated_where
  end
  workitem['fields']['receiver'] = h.applied_workitem['fields']
  super
end