Facebook chatbot using watson assistant

Sunday. January 06, 2019 - 6 mins

The main idea of this project is show how to connect a facebook chatboot in NodeJS with Watson Assistant.

What do you need?

NodeJS
Bluemix account
Facebook Page
Coffe

Step 1: Initilize your Node.js app

First of all you have to create a new directory for your Node.JS application. Open yor file explorer or command prompt and type:

mkdir AnAwesomeName
cd AnAwesomeName

Then you have to run on command prompt this line:

npm init

Step 2: Install Express.js in your application folder

While command prompt path stills in your Node.js application folder, run this line:

npm install express --save

Step 3: Start your favorite text editor (You can use Visual Studio Code or Atom)

Open index.js and replace all that contains with this code:

var bodyParser=require('body-parser');
var request=require('request');
var express = require('express');var watson = require('watson-developer-cloud');
var assistant = new watson.AssistantV1({
    username: 'Paste Assistan api username here',
    password: 'paste Assistan api password here',
    version: '2018-07-10'
});

var app = express();
app.use(bodyParser.json());
const APP_TOKEN='Paste your Facebook token here';

app.get('/', function (req, res) {
  res.send('Hello World!');
});
app.get('/webhook',function(req,res){
    if(req.query['hub.verify_token']=='Paste your Facebook Token Here '){
        res.send(req.query['hub.challenge']);
    }else{
        res.send('You cant access here ): ');
    }
});
//valida eventos
app.post('/webhook',function(req,res){
    var data=req.body;
    
    if(data.object=='page'){
        data.entry.forEach(function(pageEntry){
            pageEntry.messaging.forEach(function(messagingEvent){
                if(messagingEvent.message){
                reciveMessage(messagingEvent);
                }
            });
        });
        res.sendStatus(200);
    }//end if
});

////////////////////
//recive mensaje
function reciveMessage(event){//this function recive message an
    var senderID=event.sender.id;
    var messageText=event.message.text;
    //console.log(senderID);
    //console.log(messageText);
    sendTextToWatson(senderID,messageText);
}


function sendTextToWatson(senderId,inputText) { //This function call to Assitan api en get the answer :v
    var finalMessage='';
    assistant.message({
        workspace_id: 'Pase your workspace id here',
        input: { 'text': inputText }
    }, function (err, response) {
        if (err){
            finalMessage=err;
            //console.log('error:', err);
        }
        else{
            finalMessage=response.output.text[0];
            //console.log(JSON.stringify(response, null, 2));
            console.log("sendTextToWatson        "+finalMessage);
        }
        sendMessageText(senderId,finalMessage);

    });
}


function sendMessageText(recipientId,message){ //this function format the message
    var messageData={
        recipient:{
            id:recipientId
        },
        message:{
            text:message
        }
    };
    callSendApi(messageData);
}

function callSendApi(messageData){ //This function send text message to facebook 
    request({
        uri:'https://graph.facebook.com/v2.6/me/messages',
        qs:{access_token:APP_TOKEN},
        method:'POST',
        json:messageData
    },function(error,response,data){
        if(error){
            console.log('Error enviando msg');
        }else{
            console.log('Mensaje exitoso');
        }
    });
}
////////
var host = (process.env.VCAP_APP_HOST || 'localhost');
var port = (process.env.VCAP_APP_PORT || 3000);
app.listen(port, host);

Step 4: Add Watson Assistant to your Package.json

Your package.json maybe looks like this:

{
	"name": "NodejsStarterApp",
	"version": "0.0.1",
	"private": true,
	"scripts": {
		"start": "node app.js"
	},
	"dependencies": {
		"express": "4.15.x",
		"cfenv": "1.0.x",
		"body-parser": "1.15.0", //Only copy this line,
		"request": "2.72.0",      // and this,
		"htmlparser": "1.7.7",    //and this,
		"watson-developer-cloud": "^3.7.0"// and finally this. Please ignore everything else.
	},
	"repository": {},
	"engines": {
		"node": "6.x"
	} 
}

Step 5: Configure Facebook pages

Finally you have to configure your webhook and your facebook token with that of your index.js

You can find code files here

Mauricio Flores

An engineering student in information technology and communications.