Get Started with Voice Surveys Using PHP

To implement Voice Survey use-case in the traditional API/XML way, you can refer to the instructions in the below section to begin your implementation.

Outline

Implementation

In this section, we will guide you in setting up an app using Plivo’s API/XML to implement Voice Survey use-case. First, let’s make sure you meet these prerequisites before we dive into the code.

Prequisites

1. Create a Plivo Account(if you don’t have one already): You can sign up with your work email address and complete the phone verification step using your mobile number.
2. Set up your dev environment: To set up your dev environment in your preferred programming language, please refer to the instructions available in the Setting up the Dev Environment Guides.
3. Buy a Plivo number(optional): You must have a voice-enabled Plivo phone number if you are willing to receive incoming calls. You can purchase numbers from the Numbers section of your Plivo Console. It is also possible to purchase numbers using the Numbers API.

Prerequisites

This section will guide you through how to use Plivo APIs to make voice calls from your application. First, let’s make sure you meet these prerequisites before we dive into the code.

• Plivo Auth Id and Auth Token: You will find your Plivo Auth Id and Auth Token on the home screen of your Plivo Console. Click here to sign-up for a Plivo account if you haven’t already!

  

• Plivo Phone Number(Optional): You can purchase numbers from the Numbers section of your Plivo Console and use the same as the caller ID for the outbound call. This number will also help you receive incoming calls as you must have a voice-enabled Plivo phone number to do the same. Please note that you can also purchase numbers using the Numbers API.

  

• Answer Url: When a call is answered by the destination_number, you can control the call flow with the help of the answer_url set in the API request. Plivo will invoke the answer_url specified as soon as the call is answered and expect a valid XML response with instructions to handle the call. In addition to requests to the answer URL, Plivo initiates HTTP requests to your application server through the course of a call based on the specific XML elements in your answer XML. Such requests can be broadly classified into two categories:

  Action URL requests: XML instructions to carry forward the call are expected in response to these requests. These requests are typically invoked at the end of an XML element’s execution. For example: when an IVR input is received from the caller during a GetInput XML execution.

  Callback URL requests: No XML instructions are expected in response to these requests. Such requests serve as webhooks to notify your application server of important events through the course of an XML element’s execution. For example: when a conference participant is muted or unmuted.

Set up Your PHP Dev Environment

You must set up and install PHP and Plivo’s PHP SDK implement Voice Survey use-case. Here’s how.

Install PHP

Install Composer

Composer is a dependency manager for PHP that is used in all modern PHP frameworks, such as Symfony and Laravel. We highly recommend using Composer as the package manager for your web project.

Install Plivo PHP Package

• Create a project directory, run the following command:

  $ mkdir myphpapp
  

• Change the directory to our project directory in the command line:

  $ cd myphpapp
  

• To install the stable release, run the following command in the project directory:

  $ composer require plivo/plivo-php
  

• Alternatively, you can download this source and run

  $ composer install
  

Create the Outbound Call App

Once you have the above prerequisites set, You can follow the below instructions to create an app to implement Voice Survey use-case and redirect the call to an Automated Voice Survey IVR using a GetInput XML once the call recipients answer the call.

Now, create a file called Broadcast.php and paste the following code:

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<?php
require 'vendor/autoload.php';
use Plivo\RestClient;

$auth_id    = "Your AUTH_ID";
$auth_token = "Your AUTH_TOKEN";
$p          = new RestClient($auth_id, $auth_token);

$response = $client->calls->create('+14151234567',
                                 ['+14157654321', '+14157654322'],
                                 'https://s3.amazonaws.com/static.plivo.com/broadcast.xml',
                                 'GET');
print_r($response);

Set Up Laravel server for Incoming Calls & Callbacks.

In this section, we’ll walk you through how to set up a Laravel server in under five minutes and start handling incoming calls & callbacks.

Install Laravel & Create a Laravel Project

• Use the below command to install Laravel:

  $ composer require laravel/installer
  

As we have Laravel and its dependencies installed, we can use them to create a new Laravel project. As the initial step, using Laravel we can auto-generate code in the Laravel folder structure.

• Change the directory to our project directory in the command line:

  $ cd mylaravelapp
  

• Use the below command to start your Laravel project:

  $ composer create-project laravel/laravel quickstart --prefer-dist
  

• To install the stable release, run the following command in the project directory:

  $ composer require plivo/plivo-php
  

This will create a quickstart directory with the necessary folders & files for development.

Install Plivo

• To install a specific release, run the following command in the project directory:

  $ composer require plivo/plivo-php:4.15.0
  

• Alternatively, you can download this source and run

  $ composer install
  

This generates the autoload files, which you can include using the following line in your PHP source code to start using the SDK.

<?php
require 'vendor/autoload.php'

Create a Laravel Controller to Implement Phone System IVR

Change the directory to our newly created project directory, i.e, quickstart directory and run the below command to create a Laravel controller for inbound calls.

$ php artisan make:controller SurveyController

This will generate a controller named SurveyController in the app/http/controllers/ directory. Now, You have to open the app/http/controllers/SurveyController.php file and add the following code:

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<?php

namespace App\Http\Controllers;
require '../../vendor/autoload.php';
use Plivo\RestClient;
use Plivo\XML\Response;
use Illuminate\Http\Request;

class SurveyController extends Controller
{
    // GetInput XML to handle the incoming call
    public function ivrMain()
    {
        // This is the message that Plivo reads when the call recipient answers the call
        $Question1 = "Hi, this is a call from Plivo, How would you rate your overall satisfaction with our services? Press 1 if you are satisfied or Press 2 if you would like to suggest any improvements.";
        // This is the message that Plivo reads when the recipient provides negative feedback
        $NegativeFeedback = "We are sorry about your bad experience, One of our representatives will get in touch with you shortly.";
        // This is the message that Plivo reads when the caller does nothing at all
        $NoinputMessage = "Sorry, I didn't catch that. Please hangup and try again later.";
        // This is the message that Plivo reads when the caller inputs a wrong number.
        $WronginputMessage = "Sorry, it's a wrong input.";

        $r = new Response();
    
        $getinput_action_url = "https://example.com/firstbranch.php";
        $get_input = $r->addGetInput([
                    'action' => $getinput_action_url,
                    'method' => "POST",
                    'digitEndTimeout' => "5",
                    'inputType' => "dtmf",
                    'redirect' => "true",
                ]);
        $get_input->addSpeak($Question1);
        $r->addSpeak($NoinputMessage);
        Header('Content-type: text/xml');
        echo $r->toXML();
    }

    // Action URL block for DTMF 
    public function firstBranch(Request $request)
    {
        $Question2 = "How would you rate your satisfaction with our customer service. Press 1 for English. Press 1 if you are satisfied or Press 2 if you would like to suggest any improvements. Thanks!";
        // This is the message that Plivo reads when the recipient provides negative feedback
        $NegativeFeedback = "We are sorry about your bad experience, One of our representatives will get in touch with you shortly.";
        // This is the message that Plivo reads when the caller does nothing at all
        $NoinputMessage = "Sorry, I didn't catch that. Please hangup and try again later.";
        // This is the message that Plivo reads when the caller inputs a wrong number.
        $WronginputMessage = "Sorry, it's a wrong input.";

        $r = new Response();

        $digit = $_REQUEST['Digits'];
        if ($digit == '1'){
            $getinput_action_url = "https://example.com/secondbranch.php";
            $get_input = $r->addGetInput([
                    'action' => $getinput_action_url,
                    'method' => "POST",
                    'digitEndTimeout' => "5",
                    'inputType' => "dtmf",
                    'redirect' => "true",
                ]);
            $get_input->addSpeak($Question2);
            $r->addSpeak($NoinputMessage);
        }
        else if ($digit == '2'){
            $r->addSpeak($NegativeFeedback);
        }
        else {
            $r->addSpeak($WronginputMessage);
        }
        Header('Content-type: text/xml');
        echo $r->toXML();
    }

    // Action URL block for Sales and Support branch 
    public function secondBranch(Request $request)
    {
        // This is the message that Plivo reads when the recipient provides negative feedback
        $NegativeFeedback = "We are sorry about your bad experience, One of our representatives will get in touch with you shortly.";
        // This is the message that Plivo reads when the caller inputs a wrong number.
        $WronginputMessage = "Sorry, it's a wrong input.";

        $r = new Response();
        $digit = $_REQUEST['Digits'];
        if ($digit == '1'){
            $body = "Thank you for participating in the survey!";
            $params = array(
                'language' => "en-GB"
            );
            $r->addSpeak($body,$params);
        }
        else if ($digit == '2'){
            $r->addSpeak($NegativeFeedback);
        }
        else {
            $r->addSpeak($WronginputMessage);
        }
        Header('Content-type: text/xml');
        echo $r->toXML();
    }
}

Add a Route

Now, you need to add a route for the forward function in SurveyController class, open the routes/web.php file and add the below line:

Route::match(['get', 'post'], '/survey', 'SurveyController@ivrMain');
Route::match(['get', 'post'], '/firstbranch', 'SurveyController@firstBranch');
Route::match(['get', 'post'], '/secondbranch', 'SurveyController@secondBranch');

Now the SurveyController is ready to forward the incoming calls to your Plivo number, you can use the below command to start the Laravel server to forward incoming calls and to handle callbacks.

$ php artisan serve

Your local development server will be started and you can test the rails app for outbound calls via the URL http://127.0.0.1:8000/survey.

Exposing your local server to the internet

To receive incoming calls and to handle callbacks, your local server should be able to connect with the Plivo API service. Ngrok is a tunneling software used to expose a web server running on your local machine to the internet. Using Ngrok you can set webhooks that can talk to the Plivo server.

You can download and install ngrok from here. Follow the detailed configuration instructions to get started.

Run ngrok on the port which currently hosts your application. For example, if your port number is 8000, run the following command:

$ ./ngrok http 8000

This will give you a UI with links that look like ngrok.io/* which you can use to access your local server using the public network.

You can check the app in action on https://ff3e00858d94.ngrok.io/survey.

Test and Validate

Once you have created the Outbound Call App, You can save the file and use the below command to run your code.

$ php Broadcast.php