Facebook Messenger Webhook JSON file_get_contents为空

Question

I'm developing a bot (Facebook Messenger) and it is not responding, the 'file_get_contents' values returns null/empty.

$update_response = file_get_contents("php://input");

First I added an application to an existing page, it did not work. So I created a new page and a new application, but the error remained. I thought it might be a setting on the page or in the application.

What can be wrong?

<?php

require('parser.php');

define('BOT_TOKEN', 'FACEBOOK TOKEN');
define('VERIFY_TOKEN', 'MY TOKEN');
define('API_URL', 'https://graph.facebook.com/v2.6/me/messages?access_token='.BOT_TOKEN);

$hub_verify_token = null;

function processMessage($message) {
  // processa a mensagem recebida
  
  $sender = $message['sender']['id'];
  $text = $message['message']['text'];//texto recebido na mensagem
  
  if (isset($text)) {
        if ($text === "Mega-Sena") {
          sendMessage(array('recipient' => array('id' => $sender), 'message' => array("text" => getResult('megasena', $text))));
        } else if ($text === "Quina") {
          sendMessage(array('recipient' => array('id' => $sender), 'message' => array("text" => getResult('quina', $text))));
        } else if ($text === "Lotomania") {
          sendMessage(array('recipient' => array('id' => $sender), 'message' => array("text" => getResult('lotomania', $text))));
        } else if ($text === "Lotofácil" || $text === "Lotofacil") {
          sendMessage(array('recipient' => array('id' => $sender), 'message' => array("text" => getResult('lotofacil', $text))));
        } else {
          sendMessage(array('recipient' => array('id' => $sender), 'message' => array('text' => 'Olá! Eu sou um bot que informa os resultados das loterias da Caixa. Será que você ganhou dessa vez? Para começar, digite o nome do jogo (Lotomania, Quina, Mega ou Lotofácil) para o qual deseja ver o resultado.')));
        }
  } 
}

function sendMessage($parameters) {
  $options = array(
  'http' => array(
    'method'  => 'POST',
    'content' => json_encode($parameters),
    'header'=>  "Content-Type: application/json
" .
                "Accept: application/json
"
    )
);

$context  = stream_context_create( $options );
file_get_contents(API_URL, false, $context );
}

if(isset($_REQUEST['hub_challenge'])) {
    $challenge = $_REQUEST['hub_challenge'];
    $hub_verify_token = $_REQUEST['hub_verify_token'];
}
if ($hub_verify_token === VERIFY_TOKEN) {
    echo $challenge;
}

$update_response = file_get_contents("php://input");

//-----VERIFY LOG-----//
$fh = fopen("log.txt", "w+");
fwrite($fh, $update_response);
fclose($fh);

$update = json_decode($update_response, true);

if (isset($update['entry'][0]['messaging'][0])) {
  processMessage($update['entry'][0]['messaging'][0]);
}

?>

</div>

Answer 1

Can you try a stripped down code and check the following:

1. If your web server access logs shows a hit from facebook

2. If there are any errors (you can check this with a simple curl cli command too.

3. If logs.txt shows anything.

<?php

$hub_verify_token = null;
if(isset($_REQUEST['hub_challenge'])) {
    $challenge = $_REQUEST['hub_challenge'];
    $hub_verify_token = $_REQUEST['hub_verify_token'];
}
if ($hub_verify_token === VERIFY_TOKEN) {
    echo $challenge;
}

$update_response = file_get_contents("php://input");

//-----VERIFY LOG-----//
$fh = fopen("log.txt", "w+");
fwrite($fh, $update_response);
fclose($fh);

?>

</div>