In my previous blog post, I talked about how to do phone verification using SMS and now in this blog post I'm going to talk about how to do voice based phone verification using Twilio.
Requirement
Let's change the requirement a bit this time.
- After the user signs up, send an SMS verification. If SMS verification goes well then use that phone number for future use.
- But if the user's phone number doesn't support the SMS feature, then call on user's phone number for the verification.
- In the call, ask the user to press 1 from keypad to complete the verification. If that user presses the 1 key, then mark the phone number as verified.
Step 1: Make a call for phone verification
We already handled SMS verification, so let's add call related changes in PhoneVerificationService class.
1class PhoneVerificationService 2 attr_reader :user, :verification_through 3 4 VERIFICATION_THROUGH_SMS = :sms 5 VERIFICATION_THROUGH_CALL = :call 6 7 def initialize options 8 @user = User.find(options[:user_id]) 9 @verification_through = options[:verification_through] || VERIFICATION_THROUGH_SMS 10 end 11 12 def process 13 if verification_through == VERIFICATION_THROUGH_SMS 14 perform_sms_verification 15 else 16 make_call 17 end 18 end 19 20 private 21 22 def from 23 #phone number given by twilio 24 Settings.twilio_number_for_app 25 end 26 27 def to 28 "+1#{user.phone_number}" 29 end 30 31 def body 32 "Please reply with this code '#{user.phone_verification_code}'" << 33 "to verify your phone number" 34 end 35 36 def send_sms 37 Rails.logger.info "SMS: From: #{from} To: #{to} Body: \"#{body}\"" 38 39 twilio_client.account.messages.create ( from: from, to: to, body: body) 40 end 41 42 def make_call 43 Rails.logger.info "Call: From: #{from} To: #{to}" 44 45 twilio_client.account.calls.create( from: from, to: to, url: callback_url) 46 end 47 48 def perform_sms_verification 49 begin 50 send_sms 51 rescue Twilio::REST::RequestError => e 52 return make_call if e.message.include?('is not a mobile number') 53 raise e.message 54 end 55 end 56 57 def callback_url 58 Rails.application.routes.url_helpers 59 .phone_verifications_voice_url(host: Settings.app_host, 60 verification_code: user.phone_verification_code) 61 end 62 63 def twilio_client 64 @twilio ||= Twilio::REST::Client.new(Settings.twilio_account_sid, 65 Settings.twilio_auth_token) 66 end 67end
In PhoneVerificationService class we have added some major changes:
- We have defined one more attribute reader verification_through and in initialize method we have set it.
- We have created two new constants VERIFICATION_THROUGH_SMS & VERIFICATION_THROUGH_CALL.
- We have changed process method and now we check which verification process should be taken place based on verification_through attribute.
- We also have added new methods perform_sms_verification, make_call and callback_url.
Let's go through these newly added methods.
perform_sms_verification:
In this method, first we try to send an SMS verification. If SMS verification fails with error message like 'is not a mobile number' then in the rescue block, we make a phone verification call or we raise the error.
make_call:
In this method, we create an actual phone call and pass the all required info to twilio client object.
callback_url:
In this method, we set the callback_url which is required for Twilio for making a call. When we call the user for verification, our app needs to behave like a human and should ask to the user to press 1 to complete the verification (i.e. In the form of TwiML). This callback_url needs be to set in our app.
Step 2: Add voice action in phone verification controller
For callback_url, add route for voice action in config/routes.rb
1post 'phone_verifications/voice' => 'phone_verifications#voice'
Add voice action and required code for it in PhoneVerificationsController.
1class PhoneVerificationsController < ApplicationController 2 skip_before_filter :verify_authenticity_token 3 after_filter :set_header 4 5 HUMAN_VOICE = 'alice' 6 7 def voice 8 verification_code = params[:verification_code] 9 10 response = Twilio::TwiML::Response.new do |r| 11 r.Gather numDigits: '1', 12 action: "/phone_verifications/verify_from_voice?verification_code=#{verification_code}", 13 method: 'post' do |g| 14 15 g.Say 'Press 1 to verify your phone number.', voice: HUMAN_VOICE 16 end 17 end 18 19 render_twiml response 20 end 21 22 def verify_from_message 23 user = get_user_for_phone_verification 24 user.mark_phone_as_verified! if user 25 26 render nothing: true 27 end 28 29 private 30 31 def get_user_for_phone_verification 32 phone_verification_code = params['Body'].try(:strip) 33 phone_number = params['From'].gsub('+1', '') 34 35 condition = { phone_verification_code: phone_verification_code, 36 phone_number: phone_number } 37 38 User.unverified_phones.where(condition).first 39 end 40 41 def set_header 42 response.headers["Content-Type"] = "text/xml" 43 end 44 45 def render_twiml(response) 46 render text: response.text 47 end 48end
In this voice method, we have set up the Twilio response. When a call is made to the user, this response will get converted into robotic human voice. render_twiml method which sets twilio response in text form is required for Twilio APIs. Set up the response header in the set_header method which gets called in after_filter method.
Step 3: Set request URL for voice phone verification in Twilio
In voice action method, we have setup the request url in the action key of Twilio response object, that also needs to be set in your Twilio account. So when, user replies back to the call query, Twilio will make a request to our app and adds its own some values as parameters to the request. Using those parameters we handle the actual phone verification in the app.
Open twilio account and under NUMBERS section/tab, click on your Twilio number. Then in Voice section, add request URL with HTTP POST method. Add URL like this.
http://your.ngrok.com/phone_verifications/verify_from_voice/
We need Ngrok to expose local url to external world. Read more about it in my previous blog post.
Step 4: Add verify_from_voice action in phone verification controller
First add route for this action in config/routes.rb
1post "phone_verifications/verify_from_voice" => "phone_verifications#verify_from_voice
Add this method, in your PhoneVerificationsController.
1 def verify_from_voice 2 response = Twilio::TwiML::Response.new do |r| 3 if params['Digits'] == "1" 4 user = get_user_for_phone_verification 5 user.mark_phone_as_verified! 6 7 r.Say 'Thank you. Your phone number has been verified successfully.', 8 voice: HUMAN_VOICE 9 else 10 r.Say 'Sorry. Your phone number has not verified.', 11 voice: HUMAN_VOICE 12 end 13 end 14 15 render_twiml response 16 end
Modify private method get_user_for_phone_verification to support voice verification in PhoneVerificationsController.
1 def get_user_for_phone_verification 2 if params['Called'].present? 3 phone_verification_code = params['verification_code'] 4 phone_number = params['To'] 5 else 6 phone_verification_code = params['Body'].try(:strip) 7 phone_number = params['From'] 8 end 9 condition = { phone_verification_code: phone_verification_code, 10 phone_number: phone_number.gsub('+1', '') } 11 12 User.unverified_phones.where(condition).first 13 end
In the verify_from_voice method, we get parameters Digits, To & verification_code from Twilio request. Using these parameters, we search for user in the database. If we get the proper user then we mark user's phone number as verified phone number.