Facebook Messenger机器人问题

Question

我制作了一个Messenger聊天机器人，并首次尝试部署它，在解决了各种错误之后，我确实连接了页面，应用程序和挂钩。

强硬的人似乎可以正常工作，但该机器人没有任何反应。这就是我在错误日志中得到的内容。

我发“ hi”，什么也没有发回来。当我用Google搜索出现的响应错误时，没有适合我的解决方案。

    'use strict'

const 
    express=require('express'),
    bodyParser = require('body-parser'),
    app=express().use(bodyParser.json()); //creates http server

    app.listen(process.env.PORT || 5000, () =>console.log('webhook is listening'));

app.post('/webhook', (req, res) => {
    let body=req.body;

    if(body.object === 'page'){
        body.entry.forEach(function(entry){

            //Gets the body of the webhook
            let webhook_event=entry.messaging[0];
            console.log(webhook_event);

            //Gets the sender PSID
            let sender_psid=webhook_event.sender.id;
            console.log('Sender PSID: ' + sender_psid);

        });

        res.status(200).send('EVENT_RECEIVED');
    }else{
        res.sendStatus(404);
    }
    if(webhook_event.message){
        handleMessage(sender_psid, webhook_event.message);
    }else if(webhook_event.postback){
        handlePostback(sender_psid, webhook_event.postback);
    }

});
app.get('/', function (req, res) {
    res.send('This is EngiBot Server');
});
app.get('/webhook', (req, res) => {
    let VERIFY_TOKEN = "testbot_verify_token"

    let mode= req.query['hub.mode'];
    let token=req.query['hub.verify_token'];
    let challange = req.query['hub.challange'];

        if (req.query['hub.verify_token'] === VERIFY_TOKEN) {
        res.send(req.query['hub.challenge']);
    } else {
        res.send('Invalid verify token');
    }

    if(mode && token){
        if(mode==='subscribe' && token === VERIFY_TOKEN){

            console.log('WEBHOOK_VERIFIED');
            res.status(200).send(challange);
        }else{
            res.sendStatus(403);
        }
    }
});

function handleMessages(sender_psid, received_message){
    let response;

    if(received_message.text){
        response = {
            "text": 'You sent the message: "${received_message.text}". Now send an image!'
        }
    }else if(received_message.attachments){
        let attachment_url=received_message.attachments[0].payload.url;
        response = {
            "attachment":{
                "type": "template",
                "payload":{
                    "template_type":"generic",
                    "elements": [{
                        "title": "Is this the right picture?",
                        "subtitle": "Tap a button to answer.",
                        "image_url": attachment_url,
                        "buttons": [
                        {
                            "type": "postback",
                            "title": "Yes!",
                            "payload":"yes",
                        },
                        {
                            "type": "postback",
                            "title": "No!",
                            "payload": "no",
                        }
                        ],
                    }]
                }
            }
        }
    }

    callSendAPI(sender.psid, response);
}

function handlePostback(sender_psid, received_postback){
    let response;

    let payload=received_postback.payload;

    if(payload==='yes'){
        response = {"text": "Thanks!"}
    }else if (payload==="no"){
        response ={"text": "Oops, try sending another image."}
    }
    callSendAPI(sender_psid, response);
}

function callSendAPI(sender_psid, response){
    let request_body={
        "recipient": {
        "id": sender_psid
        },
        "message": response
    }
request({
    "uri":"",
    "qs":{"access_token": PAGE_ACCESS_TOKEN},
    "method": "POST",
"json": request_body
}, (err, res, body)=>{
    if(!err){
        console.log('message sent!')
    }else {
        console.error("Unable to send message:" + err);
    }
});
}

Answer 1

POST路由器出现问题。 “ webhook_event”在条件块内的foreach块内声明，因此其作用域在该块内。为了解决这个问题，您将重写代码以匹配范围。这是错误的路由器（我添加了一些注释=

app.post('/webhook', (req, res) => {
    let body=req.body; 
        // webhook_event == null -> true

    if(body.object === 'page'){
        body.entry.forEach(function(entry){

            //Gets the body of the webhook
            let webhook_event=entry.messaging[0]; // webhook_event declared // webhook_event == null -> false
            console.log(webhook_event);

            //Gets the sender PSID
            let sender_psid=webhook_event.sender.id;
            console.log('Sender PSID: ' + sender_psid);

        });

        res.status(200).send('EVENT_RECEIVED');
        if(webhook_event.message){ // ReferenceError cause is not defined
        handleMessage(sender_psid, webhook_event.message);
    }else if(webhook_event.postback){ // ReferenceError cause is not defined
        handlePostback(sender_psid, webhook_event.postback);
    }


    }else{
        res.sendStatus(404);
    }

});