Spacebot A Facebook Messenger Bot

Spacebot is facebook messenger bot which tells you about NASA and ISS and other cool stuff. Spacebot is developed using NodeJs. Currently it is deployed on Heroku server

Bot can tell you

• About ISS
• About NASA
• Temperature of your region
• Latest News
• Quotes,Jokes

🙌 Get set

Setup the Facebook App

1. Create or configure a Facebook App or Page here https://developers.facebook.com/apps/

2. In the app go to Messenger tab then click Setup Webhook. Here you will put in the URL of your Heroku server and a token. Make sure to check all the subscription fields.

3. Get a Page Access Token and save this somewhere.

4. Go back to Terminal and type in this command to trigger the Facebook app to send messages. Remember to use the token you requested earlier.

   curl -X POST "https://graph.facebook.com/v2.6/me/subscribed_apps?access_token=<PAGE_ACCESS_TOKEN>"

Setup the bot

Now that Facebook and Heroku can talk to each other we can code out the bot.

1. Add an API endpoint to index.js to process messages. Remember to also include the token we got earlier.

   app.post('/webhook/', function (req, res) {
       let messaging_events = req.body.entry[0].messaging
       for (let i = 0; i < messaging_events.length; i++) {
   	    let event = req.body.entry[0].messaging[i]
   	    let sender = event.sender.id
   	    if (event.message && event.message.text) {
   		    let text = event.message.text
   		    sendTextMessage(sender, "Text received, echo: " + text.substring(0, 200))
   	    }
       }
       res.sendStatus(200)
   })
   
   const token = "<PAGE_ACCESS_TOKEN>"

   Optional, but recommended: keep your app secrets out of version control!

   • On Heroku, its easy to create dynamic runtime variables (known as config vars). This can be done in the Heroku dashboard UI for your app or from the command line:

   heroku config:set FB_PAGE_ACCESS_TOKEN=fake-access-token-dhsa09uji4mlkasdfsd
   
   # view
   heroku config

   • For local development: create an environmental variable in your current session or add to your shell config file.

   # create env variable for current shell session
   export FB_PAGE_ACCESS_TOKEN=fake-access-token-dhsa09uji4mlkasdfsd
   
   # alternatively, you can add this line to your shell config
   # export FB_PAGE_ACCESS_TOKEN=fake-access-token-dhsa09uji4mlkasdfsd
   
   echo $FB_PAGE_ACCESS_TOKEN

   • config var access at runtime

   const token = process.env.FB_PAGE_ACCESS_TOKEN

2. Add a function to echo back messages

   function sendTextMessage(sender, text) {
       let messageData = { text:text }
       request({
   	    url: 'https://graph.facebook.com/v2.6/me/messages',
   	    qs: {access_token:token},
   	    method: 'POST',
   		json: {
   		    recipient: {id:sender},
   			message: messageData,
   		}
   	}, function(error, response, body) {
   		if (error) {
   		    console.log('Error sending messages: ', error)
   		} else if (response.body.error) {
   		    console.log('Error: ', response.body.error)
   	    }
       })
   }

3. Commit the code again and push to Heroku

   git add .
   git commit -m 'updated the bot to speak'
   git push heroku master
   

4. Go to the Facebook Page and click on Message to start chatting!

Development

Want to contribute? Great!

License

MIT