How did I build a Facebook Messenger chatbot for Tableau’s ‘VizOfTheDay’ feed

What is Viz Of The Day

It’s a Tableau Public product used mainly for promoting Tableau as a brand.

https://public.tableau.com/s/gallery

What is Facebook Messenger chatbot

https://developers.facebook.com/blog/post/2016/04/12/bots-for-messenger/

What can my bot do?

• Users can query VizOfTheDay on any date through either a hardcoded format, or natural language (which will be processed by wit.ai). If the bot doesn’t find that or cannot recognize the message, it will return a random one for users.
• Users can subscribe to VizOfTheDay, so that when a new viz is published on Tableau Public, users will be notified on Messenger App by a push notification. Of course, they can also unsubscribe it.

How does the system look like

• Backend running on a single AWS EC2
• ELB as gateway, to bind a domain name for https
• Using DynamoDB for storage
• Calling Facebook Messenger API to create UI
• Taking advantages of wit.ai for some natural language processing

Modules and their Responsibilities:

• FeedProcessor
• periodically retrieves VizOfTheDay from a Tableau Public endpoint
• serves queries of viz on a specified date (can be today or any date before)
• Controller
• receives, processes, and interprets requests from Facebook Messenger
• distributes interpretted requests to corresponding services
• Response Service
• Takes responsibilities of replying requests
• Supports different kind of templates, from pure text, pure thumbnails, to a combination of text thumbnails, and multiple tabs
• User Service
• Stores and serves queries on users’ meta data (id, first and last name, etc) and subscription options (subscribed or not)
• Data is cached in memory for faster access to properties like first name and subscription option
• Data is persisted in DynamoDB
• Profile Querying Service
• Takes a user id and query its meta data against Facebook Graph API
• Push Notifier Service
• Runs daily
• Once detects a new viz from FeedProcessor, push it to all subscribed users by getting users from User Service

Facebook Messenger API
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AWS ELB
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AWS EC2
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Controller ----------- wit.ai
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enqueue id | |
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DynamoDB -- User Service ------ Response Service
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Profile Querying Serivce | |
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Push Notifier |
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Feed Processor----------