Tutorial code for making Facebook chatbot.

+node_modules

++2019/5/25
++mother project : LINEBOT
++new project : 페이스북 메신저 기반 컴공/소융 강의평가 봇
++

+var express = require("express");
+var request = require("request");
+var bodyParser = require("body-parser");
+
+var app = express();
+app.use(bodyParser.urlencoded({extended: false}));
+app.use(bodyParser.json());
+app.listen((process.env.PORT || 5000));
+
+// Server index page
+app.get("/", function (req, res) {
+  res.send("Deployed!");
+});
+
+// Facebook Webhook
+// Used for verification
+app.get("/webhook", function (req, res) {
+  if (req.query["hub.verify_token"] === "process.env.VERIFICATION_TOKEN") {
+    console.log("Verified webhook");
+    res.status(200).send(req.query["hub.challenge"]);
+  } else {
+    console.error("Verification failed. The tokens do not match.");
+    res.sendStatus(403);
+  }
+});
+
+// All callbacks for Messenger will be POST-ed here
+app.post("/webhook", function (req, res) {
+  // Make sure this is a page subscription
+  if (req.body.object == "page") {
+    // Iterate over each entry
+    // There may be multiple entries if batched
+    req.body.entry.forEach(function(entry) {
+      // Iterate over each messaging event
+      entry.messaging.forEach(function(event) {
+        if (event.postback) {
+          processPostback(event);
+        }
+      });
+    });
+
+    res.sendStatus(200);
+  }
+});
+
+function processPostback(event) {
+  var senderId = event.sender.id;
+  var payload = event.postback.payload;
+
+  if (payload === "Greeting") {
+    // Get user's first name from the User Profile API
+    // and include it in the greeting
+    request({
+      url: "https://graph.facebook.com/v2.6/" + senderId,
+      qs: {
+        access_token: process.env.PAGE_ACCESS_TOKEN,
+        fields: "first_name"
+      },
+      method: "GET"
+    }, function(error, response, body) {
+      var greeting = "";
+      if (error) {
+        console.log("Error getting user's name: " +  error);
+      } else {
+        var bodyObj = JSON.parse(body);
+        name = bodyObj.first_name;
+        greeting = "Hi " + name + ". ";
+      }
+      var message = greeting + "My name is SP Movie Bot. I can tell you various details regarding movies. What movie would you like to know about?";
+      sendMessage(senderId, {text: message});
+    });
+  }
+}
+
+// sends message to user
+function sendMessage(recipientId, message) {
+  request({
+    url: "https://graph.facebook.com/v2.6/me/messages",
+    qs: {access_token: process.env.PAGE_ACCESS_TOKEN},
+    method: "POST",
+    json: {
+      recipient: {id: recipientId},
+      message: message,
+    }
+  }, function(error, response, body) {
+    if (error) {
+      console.log("Error sending message: " + response.error);
+    }
+  });
+}

+{
+  "name": "spbot",
+  "version": "1.0.0",
+  "description": "SPBot Server",
+  "main": "app.js",
+  "scripts": {
+    "test": "echo \"Error: no test specified\" && exit 1",
+    "start": "node app.js"
+  },
+  "author": "WonJun Choi",
+  "license": "ISC",
+  "dependencies": {
+    "body-parser": "^1.19.0",
+    "express": "^4.17.0",
+    "mongoose": "^5.5.11",
+    "request": "^2.88.0"
+  }
+}