sinatra, ruby and twilio [facilitating a CALLBACK mechanism] - ruby

Question

I would like to do the following:
Call my twilio number from my cell phone
My twilio number identifies the incoming number then immediately hangs up
My twilio number calls back the identified number (my cell phone number)
When I pick up, twilio asks me to enter the number I wish to call
Twilio gathers the input of the number I want to call and connects me.
So I can make cheap international calls (or roaming calls) from my cell phone.
So far, taken from the twilio website api docs, I have:
require 'rubygems'
require 'sinatra'
require 'twilio-ruby'
get '/' do
account_sid = 'xxxxxxx'
auth_token = 'zzzzzzz'
to = params['From']
#to = '[phone]'
#to = '441903773807'
from = '442033222327'
Twilio::TwiML::Response.new do |r|
r.Hangup
end.text
# set up a client to talk to the Twilio REST API
#client = Twilio::REST::Client.new account_sid, auth_token
#call = #client.account.calls.create(
:from => from, # From your Twilio number
:to => to, # To any number
:timeout => "20",
# Fetch instructions from this URL when the call connects
:url => 'https://dl.dropboxusercontent.com/u/85088004/twilio/twilio.xml'
)
end
post '/makecall' do
warn params.inspect
account_sid = ' ACaf2b951ae6f7424da036ea9dcd5b0d91'
auth_token = 'my token'
#client = Twilio::REST::Client.new account_sid, auth_token
call = #client.account.calls.create(:url => "https://dl.dropboxusercontent.com/u/85088004/twilio/callback.xml",
:to => params[:Digits],
:from => "[phone]")
puts call.to
end
The twilio.xml, in the '/' section url file is:
<?xml version="1.0" encoding="UTF-8"?>
<Response>
<Gather action="/makecall" method="POST">
<Say timeout="10">Enter the number you wish to call</Say>
</Gather>
</Response>
I get "Sorry an application error has occurred." Then it just hangs up.
warn params.inspect
does not produce anything when I inspect the heroku logs. So I think (one of) the problem(s) is that the params of the number I am dialling is not passed.
Is there any other problem with logic or scripting that seems obvious?
Does the problem lie with the url in the '/makecall' snippet? It si:
<?xml version="1.0" encoding="UTF-8"?>
<Response>
</Hangup>
</Response>
Many, many thanks!

Answer 1

SOLVED!! Thank you for help from the T evangelist. Here is the solution:
require 'rubygems'
require 'sinatra'
require 'twilio-ruby'
account_sid = 'my sid'
auth_token = 'my token'
get '/' do
from = 'my T number'
to = params[:From]
Twilio::TwiML::Response.new do |r|
r.Hangup
end.text
sleep 10
# set up a client to talk to the Twilio REST API
#client = Twilio::REST::Client.new account_sid, auth_token
#call = #client.account.calls.create(
:from => from, # From your Twilio number
:to => to, # To any number
# Fetch instructions from this URL when the call connects
:url => 'https://dl.dropboxusercontent.com/u/85088004/twilio/twilio.xml'
)
end
# the xml file. It is VERY IMPORTANT that you have the absolute url in the action=""
<?xml version="1.0" encoding="UTF-8"?>
<Response>
<Gather timeout="20" action="http://dry-journey-9071.herokuapp.com/makecall" method="GET">
<Say voice="alice">Enter the destination number, please.</Say>
</Gather>
<Say voice="alice">Input not received. Thank you</Say>
</Response>
#Back to the app:
get '/makecall' do
number = params[:Digits]
Twilio::TwiML::Response.new do |r|
r.Dial number ### Connect the caller to Koko, or your cell
r.Say 'The call failed or the remote party hung up. Goodbye.'
end.text
end
Yay!

Answer 2

Twilio Developer Evangelist here.
When you detect that it is your own number, you want to return some TwiML (XML) to Twilio, this should suffice: <Response> <Hangup/> </Response>
You would then need to make a REST API call to Twilio to make a new outbound call to yourself:
#client.account.calls.create(to: my_number, from: "+sometiwilionumber", url: "http://example.com/make-other-call-twiml")
Then use the URL of some TwiML to <Gather> the number you want to dial, and simply <Dial> to that number...
The thing you want to avoid is having Twilio call you back before the first call ends. As you will need to make the API call first, we need to use threading to get around it. I'm not bad with Ruby/Sinatra, but I'm no expert with threading here, but this should work:
twilio_call_thread = Thread.new{
sleep 3 #3 Seconds should be plenty, but you may want to experiment.
#client.account.calls.create(to: mynumber, from: some_twilio_number, url: "http://example.com/gather-and-dial")
}
#Then return the TwiML to hangup...
"<Response><Hangup/></Response>"
You call your number, it creates a thread, then goes to sleep. It responds with a <Hangup> to disconnect the call. A few seconds later, the thread wakes up and you'll get the return call. You will need some TwiML on that call to do a <Gather> to get the phone number to dial, and then <Dial> to make the actual call.
I wasn't sure about the threading, so before checking on that, I had two other ideas you could use:
Use SMS. Send you Twilio number the other number you want to dial, and just have Twilio make the call directly between your number, and the other number.
Secondly, just use a URL, presuming you have data on your phone you can just open a URL which does the same without the initial call or SMS.
Oh - and a third option, if you don't want to muck about with threads, or that's not working for you: set the Status Callback URL on your Twilio number (click 'Optional Voice Settings'). This is fired after the call completes, and from there you can make the new call to yourself.
Hope you get it sorted, it's going to be awesome.