Question

I am using Twilio in my rails 3.1.3 app and I have got everything basically set up, i.e. a controller for sms and xml builders for the views depending on the response. The only thing I can’t figure out is how to keep track of the conversation. The Twilio docs are pretty bad for using anything other than PHP to do this. I have tried using the Rails session hash, session[:variable], but it doesn’t seem to be saving the session, as I tried redirecting and printing it out and got nothing. Below is the code of the controller.

  def receive
    # Check for session variable and redirect if necessary
    @sms_state = session[:sms_state]
    if @sms_state == 'confirmation'
      redirect_to 'confirm'
    end
    if condition
      @sms_state = 'confirmation'
      session[:sms_state] = @sms_state
      render :action => "view.xml.builder", :layout => false
    else
      @sms_state = 'new_state'
      session[:sms_state] = @sms_state
      render :action => "error.xml.builder", :layout => false
    end
  end
  # method that should be called after user deals with first part
  def confirm
    if condition
      @sms_state = session[:sms_state] = nil
      render :action => "confirm_view.xml.builder", :layout => false
    else
      @sms_state = 'confirmation'
      session[:sms_state] = @sms_state
      render :action => "error.xml.builder", :layout => false
    end
  end

I have now set up a database table to track the current conversation state depending on the phone number contacting my app. The only thing now that I need to do is set an expiration for this conversation, just like a session or cookie. I am not sure how to do this or if its even possible.

Answer 1

This depends on how you define “conversation”, but in general, you are better off using some sort of persistance (would recommend database over a file), and build the structure in accordance with your definition of a conversation.

Suppose the conversation is defined as text messages between two 10-digit phone numbers without a time limit, you can setup a db with a sender and recipient attributes, so if you need to output something in a user interface, you can look for sender and recipient phone numbers, and display all messages coming to them or going from them.

SMS is different from a phone call, since you can set cookies for the session of a phone call. SMS is done when either delivered or sent. When you receive an SMS to a phone number or short code, Twilio will make a request to the URL you provided for SMS, and your app can then respond. If you receive another response, it’s a brand new request, so you have to construct the notion of “conversation”.