Queue using Twilio – Part III

In Part II, we have accepted the incoming call and enqueued the user to queue named ‘support’. Further we will play a music on hold while waiting for the agent to answer the call or the user to send a DTMF to register a callback or until the timeout which is 10 minutes by default

from twilio.twiml.voice_response import VoiceResponse, Gather
from twilio.rest import Client
import json, os

def lambda_handler(event, context):
    params = event['body']
    res  = {}
    for pair in params.split('&'):
        key, _, value = pair.partition('=')
        res[key] = str(value)

    caller = res['Caller']
    response = VoiceResponse()

        gather = Gather(input='dtmf', num_digits=1, action='/v1/callbackregister', method='POST')
        gather.play("http://com.twilio.sounds.music.s3.amazonaws.com/BusyStrings.mp3")
        response.append(gather)

    return {
        'statusCode': 200,
        'headers': {
            'Content-Type': 'text/xml'
        },
        'body': str(response)
    }

From the POST request we extract the caller value to identify the user’s phone number or client id (if using voiceSDK)

for pair in params.split('&'):
        key, _, value = pair.partition('=')
        res[key] = str(value)

caller = res['Caller']

        gather = Gather(input='dtmf', num_digits=1, action='/v1/callbackregister', method='POST')
        gather.play("http://com.twilio.sounds.music.s3.amazonaws.com/BusyStrings.mp3")
        response.append(gather)

1. Gather function has few options. Here we use the input as ‘dtmf‘ digits. This can be also ‘speech‘ so that we can leverage to recognize user’s speech.
2. num_digits says how many maximum number of digits can be obtained before the timeout (default timeout is 5 seconds)
3. ‘action’ is the URL where the gathered input will be sent to further processing and the HTTP method to be used to send to the URL is POST

1. In this Gather function we will wait for user to provide a single digit DTMF input and send the call to another lambda function using the URL ‘/v1/callbackregister‘ using HTTP POST method
2. While waiting for the input we will play a music on hold from the link http://com.twilio.sounds.music.s3.amazonaws.com/BusyStrings.mp3 in loop until an agent answers the call or call times out.

Continue reading Part IV