FB Messenger Bot: Webhook updates not being delivered - php

Question

i am working with Facebook Checkbox Plugin everything is working fine except facebook is not sending request to my webhook url when Confirming Opt-in.
in facebook docs it is mentioned that
After the opt-in event, we will post a webhook event to your server if the checkbox state was checked. This callback has the same format as the opt-in callback, but instead of a sender field, it has an optin object with a user_ref field.
But it is not sending any data. here is my webhook code
if (!empty($_REQUEST['hub_mode']) && $_REQUEST['hub_mode'] == 'subscribe' && $_REQUEST['hub_verify_token'] == 'verificationtoken') {
echo $_REQUEST['hub_challenge'];
}
$data = file_get_contents("php://input");
$fp = file_put_contents( PROTECH_FBB_DIR.'/data.log', $data);
i have also tried hitting my webhook manually and see if it responds. and it does work perfectly normal, so it means facebook is not posting data or maybe i am doing something wrong?
Any help would be highly appreciated. thanks

Answer 1

I am not php developer but have implemented the same logic in javascript, node.js. I would like to share the steps in detail and also the javascript code and hope you can figure out what you can do with it to make your life better :P
As you said, you are receiving the user_ref from the api call. That's correct. Read the documentation once again they have mentioned the user_ref will be received when user check the checkbox plugin. This user_ref is set by you and every-time the page loads this user_ref must be unique then only the checkbox plugin will render, if it is not unique the plugin wont render. And here is the complete logic behind it. You generate the user_ref, when user check the checkbox, you receive this unqiue user_ref, using this user_ref you send message to the user(you can send message to user using user_ref as many time as you want but I will suggest you rather use senderId). When you send the message to user using user_ref, the webhook api will give you a response containing senderId of the user which is actually psid we normally use in our app. This is what you need to save in your db.
Now I will put my code here how I did it.
Receiving the user_ref and sending message to user:
My payload:
function sendTextMessageRef(user_ref, messageText,md) {
var messageData = {
recipient: {
user_ref: user_ref
},
message: {
text: messageText,
metadata: md
}
};
callSendAPI(messageData);
}
function callSendAPI(messageData) {
request({
uri: 'https://graph.facebook.com/v2.6/me/messages',
qs: { access_token: PAGE_ACCESS_TOKEN },
method: 'POST',
json: messageData
}, function (error, response, body) {
if (!error && response.statusCode == 200) {
var recipientId = body.recipient_id;
var messageId = body.message_id;
if (messageId) {
console.log("Successfully sent message with id %s to recipient %s",
messageId, recipientId);
} else {
console.log("Successfully called Send API for recipient %s",
recipientId);
}
} else {
console.error("Failed calling Send API", response.statusCode, response.statusMessage, body.error);
}
});
}
Now, after sending the message, I receive a response in this json format which will include the sender id of the user:
{"sender":{"id":"xxxxxxx"},"recipient":{"id":"xxxxxWhat you are looking for is this*******"},"timestamp":1504698781373,"message":{"is_echo":true,"app_id":xxxxxxxxxxxxxxx,"metadata":"INVITATION__REPLY__qwe__2017-09-05T02xo20__xxxxxxxx__063__yes","mid":"mid.$cAAGcxxxxxxxxVxuAtJ","seq":120162,"text":":)"}}
In above received json data, the recipient.id is what you are looking for.
Here To make you understand what I did in my chat bot is first user select the checkbox plugin, I receive the call on my server, if check if it contains user_ref, if yes then I send a text message to user with a custom metadata using user_ref. When user receives the message, the webhook send me a json data in the above given format. To identify for which user_ref I have received this response, I set custom metadata which is combination of some string+user_ref. Using this I identify the sender.id of the user for which I previously sent message using user_ref. The sender.id is my pageid and recipient.id the the user id which you are trying to get and using which we generally send message to the user and is also know as psid.
Hope this helps, if you still get some issue using the above mentioned solution, then do update about it :)