Get Started with Conference Calling with a PIN Using PHP

To implement Conference with pin use-case in the traditional 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 to receive a call on your Plivo number and add the caller(s) to a conference call using Plivo XML. In this example, when an incoming call is received, Plivo will add the caller(s) using the <Conference> XML.

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. Buy a Plivo Number: 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.

3. Answer URL & Callback URLs: When a call is received on a Plivo voice-enabled number, you can control the call flow by declaring an answer URL for your Plivo application associated with that Plivo phone number. Plivo will invoke the answer URL specified and expect a valid XML response to handle the call.

   Notice how the concept of Answer URLs applies to both outbound API calls as well as incoming calls to your Plivo numbers. In the outbound API call example in the Make-Outbound-Calls use-case guide, we specified the answer URL along with the make call API request, whereas in the case of incoming calls to Plivo numbers, the answer URL is specified in the Plivo application associated with the phone number.

   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.

4. Set Up Your Web Server: To be able to host Answer and Callback URLs and to be able to provide valid XMLs and accept notifications on these URLs respectively, you need to host a webserver at your end. To set up your Web Server in your preferred programming language, please refer to the instructions available in the Set Up Laravel Server for Incoming Calls & Callbacks section.

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 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 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 Conference with Pin

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 ConferencecallController

This will generate a controller named ConferencecallController in the app/http/controllers/ directory. Now, You have to open the app/http/controllers/ConferencecallController.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 ConferencecallController extends Controller
{
    // GetInput XML to handle the incoming call
    public function conferenceCall()
    {
        $welcome_message = "Welcome to the Plivo Conference with Pin Demo App. Press 1234 to listen to join the conference."; //  Welcome message - firstbranch
        $no_input = "Sorry, I didn't catch that. Please hangup and try again later."; // This is the message that Plivo reads when the caller does nothing at all
        $response = new Response();
        $get_input = $response->addGetInput(
                    [
                        'action' => "https://dc40fc05d7dc.ngrok.io/conference/confbranch",
                        'method' => "POST",
                        'digitEndTimeout' => "5",
                        'numDigits' => "4",
                        'inputType' => "dtmf",
                        'redirect' => "true",
                    ]);
        $get_input->addSpeak($welcome_message, ['language'=>"en-US", 'voice'=>"Polly.Salli"]);
        $response->addSpeak($no_input);
        Header('Content-type: text/xml');
        echo $response->toXML();
    }

    // Action URL block for Sales and Support branch 
    public function confBranch(Request $request)
    {
        $wrong_input = "Sorry, it's a wrong input."; // This is the message that Plivo reads when the caller inputs a wrong digit.
        $digit = $request->query('Digits');
        $response = new Response();
        if ($digit=="1234") {
            $params = array(
                'startConferenceOnEnter' => "true",
                'endConferenceOnExit' => "true"
            );
    
            $conference_name = "My Room";
            $response->addConference($conference_name, $params);
        } else {
            $response->addSpeak($wrong_input);
        } 
        Header('Content-type: text/xml');
        echo $response->toXML();
    }
}

Add a Route

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

Route::match(['get', 'post'], '/conference', 'ConferenceCallController@conferenceCall');
Route::match(['get', 'post'], '/conference/confbranch', 'ConferenceCallController@confBranch');

Now the ConferencecallController 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/conference/.

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/conference.

Create a Plivo Application

1. Create an Application by visiting the Application Page and click on New Application or by using Plivo’s Application API.
2. Give your application a name. Let’s call it Conference Call. Enter your server URL (e.g., http://www.example.com/response/conference) in the Answer URL field and set the method as POST. See our Application API docs to learn how to modify your application through our APIs.
3. Click on Create Application to save your application.

Assign a Plivo number to your app

1. Navigate to the Numbers page and select the phone number you want to use for this app.
2. Select Conference Call (name of the app) from the Plivo App dropdown list.
3. Click on Update Number to save.

Test and validate

When you make a call to your Plivo number, you will be placed into a conference after passcode validation.