Question

I am making a private message system and I’m using state machine for to know where is a message.

This is my model:

class Message
  include Mongoid::Document
  include Mongoid::Timestamps::Created

  #fields
  field :subject, :type => String
  field :body, :type => String
  field :place, :type => String
  field :has_been_read, :type => String

  # Relationships 
  belongs_to :sender, :class_name => 'User', :inverse_of => :messages_sent
  belongs_to :receiver,   :class_name => 'User', :inverse_of => :messages_received

  #state machine has been read message?
    state_machine :has_been_read, :initial => :unread do
    event :read_message do
    transition :from => :unread, :to => :read
   end
   event :mark_unread do
     transition :from => :read, :to => :unread
   end
  end
  #state machine status can be in_box, sent, draft, trash, spam
end

user model:

class User
 include Mongoid::Document
 include Mongoid::Timestamps::Created
.
.
.
  has_many :messages_sent, :class_name => 'Message', :inverse_of => :sender
  has_many :messages_received, :class_name => 'Message', :inverse_of => :receiver
.
.
.
end

1º How can a message is at the same time on sent or inbox place?

2º What initial state have a message for sender and receiver user?

Sorry but I’m newbie with state_machine gem

Thank you very much

Answer 1

It looks like you’re trying to track two things here (read status and delivery state) and you’re currently combining them together. I think it actually makes sense and would be much cleaner to keep these separate.

I would recommend the following:

1. In your state-machine, keep track of the message state: draft, outbox, sent, inbox, trash, etc.

2. Separately keep a read_at field in your model that stores the datetime that the message was viewed by the recipient and default this value to nil.

   field :read_at, type: DateTime, default: nil

3. Add a boolean method to your document for checking read status:

   def read?
!@read_at.nil?
end