System Initiated IVR Call to trap Voice Response - twilio

Question

I need to make an IVR app in php where the syetm initiates the outbound call and traps a voice response from user.
How may i go about doing this?
This is my code (does not trap response from user)
voice.xml contents
<?xml version="1.0" encoding="UTF-8"?>
<!-- page located at http://example.com/complex_gather.xml -->
<Response>
</Response>
completed.php contents
file_put_contents('voice.txt',$_SERVER['QUERY_STRING']);
Main Code
<?php
require_once 'vendor/autoload.php';
use Twilio\Rest\Client;
use Twilio\TwiML\VoiceResponse;
// Find your Account SID and Auth Token at twilio.com/console
// and set the environment variables. See http://twil.io/secure
$sid = "xxx";
$token = "xxx";
$twilio = new Client($sid, $token);
$call = $twilio->calls
->create("+1310XXXXXXX", // to
"[phone]", // from
[
"method" => "GET",
"statusCallbackMethod" => "POST",
"url" => "http://xxxx.com/voice.xml"
]
);
$response = new VoiceResponse();
$gather = $response->gather(['action' => '/completed.php','method' => 'GET', 'input'=>'speech','timeout'=>3,''=>'true','speech_model'=>'phone']);
$gather->say('Enter something, or not');
echo $response;

Answer 1

Twilio developer evangelist here.
When you create a call through the Twilio API, as you are doing, you pass a URL parameter.
When the call connects, Twilio will make a webhook (HTTP) request to that URL and will follow the instructions that are returned in the form of TwiML.
Currently your /voice.xml endpoint returns an empty <Response/> which will cause the call to hang up as there is no TwiML to execute.
Instead of returning an empty <Response/> from /voice.xml you should return the TwiML you generate at the end of your script.
So, perhaps voice.xml should be voice.php and look a bit like this:
<?php
require_once 'vendor/autoload.php';
use Twilio\Rest\Client;
use Twilio\TwiML\VoiceResponse;
header('Content-Type: application/xml');
$response = new VoiceResponse();
$gather = $response->gather(['action' => '/completed.php','method' => 'GET', 'input'=>'speech','timeout'=>3,''=>'true','speech_model'=>'phone']);
$gather->say('Enter something, or not');
echo $response;
You should also return TwiML from your completed.php endpoint too.
<?php
file_put_contents('voice.txt',$_SERVER['QUERY_STRING']);
header('Content-Type: application/xml');
?>
<Response/>