Line-Dialogflow Adapter for Firebase Functions

Line-Dialogflow Adapter helps pass events from Line Messaging API to Dialogflow. Normally, the events such as Follow event and Postback event are not supported out-of-the-box by Dialogflow yet. Hence, the bot can only send text query to get the response from Dialogflow. This code seeks to translate Line webhook events to Dialogflow custom events. Click here to see the bot in action.

*Note: This code will deploy the adapter on Firebase Cloud Functions. If you want to deploy on Express see here.

Quickstart

1. Create a bot in Dialogflow. Remember your project-id and language. No need to set up the Integrations for Line.
2. Enable the Dialogflow API in Google Cloud console for your project.
3. Initialize Firebase project

cd line-dialogflow-adapter-firebase
firebase init

and select your project-id to match your Dialogflow project.

4. Obtain the channel access token of your Line bot from Line Developer console.

5. Set up the config with

firebase functions:config:set line.channel_access_token="your-channel-access-token" dialogflow.project_id="your-project-id" dialogflow.language_code="your-language"

6. Deploy the function with

firebase deploy --only functions

You should get the URL of your function as https://us-central1-your-project-id.cloudfunctions.net/webhook and the link will also show up at your Firebase Functions Dashboard.

7. Go to your Firebase console. Select the Blaze pricing plan. Firebase function would not allow external API call using free plan 😱.

8. Go to the Line Channel Setting of your bot.

   • Enable webhook and add the Webhook URL to point to https://us-central1-your-project-id.cloudfunctions.net/webhook.
   • Disable Auto-reply messages and Greeting messages

9. Go to Dialogflow console. For Default Welcome Intent, add LINE_FOLLOW event to greet your audience from Dialogflow!

Line webhook event to Dialogflow event

• Message event is simply sent to Dialogflow as text.
• Follow, Join, Beacon event are sent as custom Dialogflow events below:

Line	Dialogflow
Follow	LINE_FOLLOW
Join	LINE_JOIN
Beacon	LINE_BEACON

• Postback event are sent as <EVENT_NAME> to Dialogflow with all the followed parameters. The parameters may be used in the Dialogflow responses as #your_event_name.param (ie. My store id is #your_event_name.storeid will return My store id is 1234 from the example below).

{  
   "type":"postback",
   "replyToken":"b60d432864f44d079f6d8efe86cf404b",
   "source":{  
      "userId":"U91eeaf62d...",
      "type":"user"
   },
   "timestamp":1513669370317,
   "postback":{  
      "data":"action=<EVENT NAME>&storeid=1234",
      "params":{  
         "datetime":"2017-12-25T01:00"
      }
   }
}

Feel free to customize the name of the predefined Dialogflow events and <EVENT_NAME> selector (default is action) in config.ts.

Documentation

• View Line webhook event
• View Dialogflow event