How can I determine if the call recipient hangs up during a Twilio call in rails

Question

I have the following simple callback to handle Twilio calls. I ask the user to press any keypad button to continue. If the call recipient doesn't press a key, the question is asked again. How can I determine if the call recipient hangs up. At present, if the call is answered and then hung-up, My redirect route continues the get hit until I give up asking to press any key. There can be a minute delay before the hangup and the point when my app stops receiving hits.

  def response
    Twilio::TwiML::Response.new do |r|
      r.Gather finishOnKey: '#', numDigits: @num_digits,
        timeout: @phone_wait_time,
        action: NGROK +
          voice_path(@notification.id, @final_question_response) do |g|
          g.Say @latest_question.text, voice: 'alice', language: 'en-AU'
      end
      r.Redirect NGROK +
        voice_redirect_path(@notification.id, @final_question_response)
    end.to_xml
  end

EDIT

Here's a bit more information on the problem I have and what I'm trying to do. I'll use an example.

1) I make an outgoing call as follows

  def call_phone
    client = Twilio::REST::Client.new(
      Rails.application.secrets.twilio_sid,
      Rails.application.secrets.twilio_token
    )
    call = client.account.calls.create(
      from: Rails.application.secrets.twilio_voice_number,
      to: @phone_number,
      url: NGROK + question_path(@notification.id),
      method: 'GET',
      statusCallback: NGROK + call_status_path(@notification.id),
      statusCallbackEvent: [:initiated, :ringing, :answered, :completed]
    )
  end

2) My statusCallback is hit with the usual, initiated, ringing etc. The call recipient picks up the phone and the statusCallback is hit with in-progress. My question_path is hit as per the url: defined in 1 above. After some processing my response is called as follows

  def response
    Twilio::TwiML::Response.new do |r|
      r.Gather finishOnKey: '#', numDigits: @num_digits,
        timeout: @phone_wait_time,
        action: NGROK +
          voice_path(@notification.id, @final_question_response) do |g|
          g.Say @latest_question.text, voice: 'alice', language: 'en-AU'
      end
      r.Redirect NGROK +
        voice_redirect_path(@notification.id, @final_question_response)
    end.to_xml
  end

3) @latest_question.text says Please press any key to continue. If the call recipient hangs up, I would like to terminate the call. I was hoping my statusCallback would be hit with a status letting me know the call recipient has hung up. It doesn't do that and I don't know it has happened. After a timeout, my voice_redirect_path is hit. There is no response so I ask the question again. I still don't know the call has hung up. I continue asking the question and everything continues on as if the call recipient was still on the line. This continues on until I give up and hang up on the call. Then my statusCallback is hit with a status of completed.

Thanks in advance.

Answer 1

Twilio developer evangelist here.

That's weird that you wouldn't immediately get a hangup event from the status callback. If you could email me at philnash@twilio.com with a call SID where this happens, I will raise it with the team internally (though I'm on holiday this week, so it might be quicker to go through the support team).

To work around this, you could use a count parameter when you redirect to the voice_redirect_path and hang up yourself when the count reaches too high. Something like:

  def response
    Twilio::TwiML::Response.new do |r|
      @count = params[:count] || 0
      if @count > MAX_REDIRECTS
        r.Hangup
      else
        r.Gather finishOnKey: '#', numDigits: @num_digits,
          timeout: @phone_wait_time,
          action: NGROK +
            voice_path(@notification.id, @final_question_response) do |g|
            g.Say @latest_question.text, voice: 'alice', language: 'en-AU'
        end
        r.Redirect NGROK +
          voice_redirect_path(@notification.id, @final_question_response, :count = @count+1)
      end
    end.to_xml
  end

This would allow you to set a max number of redirects while waiting for an answer.

Let me know if this helps at all.