README.md

Twilio Barista

How does it work?

1. Send message with order

A customer sends a message to the configured Messaging Service. This happens via WhatsApp to a respective phone number.

2. Message forwarded to "incoming webhook"

Twilio will receive this message and do an HTTP POST request to the configured webhook URL that has been configured during the setup period. This HTTP POST request contains a variety of information including a Body property that contains the message sent by the user, Author the address (e.g. phone number) of the user and the To property that contains the address the message was sent to (like the Message Service SID).

The route of the webhook is /api/webhook/incoming. The POST request is being handled in the incoming webhook file. It will perform the following things:

a) If the person messages in the first time in a while and there is more than one event with isVisible to true:

• It will prompt the user which event they are at. It will remember the order until the person picked an event

b) The user is already registered for an event or there is only one event:

• parse message to determine intent and which drink is being ordered
• create an entry in the Twilio Sync customer Map
• create an entry in the Twilio Sync open orders List
• create an entry in the Twilio Sync all orders List
• send reply message to the user via Twilio Conversations

3. Order created in Twilio Sync List

If the user ordered a drink the incoming message webhook will create a new item in the open orders List that works like a queue for the orders. The structure of the data added to the queue can be checked out in the Data Structures documentation.

4. Reply message sent to user

The reply is sent to the respective conversation using the Twilio Conversations REST API.

5. Order appears on tablet

The order will immediately appear in real-time on the web interface under the /orders URL using the Twilio Sync JavaScript SDK.

6. Barista changes status of order

When the barista finished the order they will click one of the two buttons that change the status property of that entry in the List to 'cancelled' or 'ready'.

7. Change triggeres "sync webhook"

Twilio will automatically trigger an HTTP POST request to the webhook endpoint /api/webhook/sync for every change of an item associated to the configured Twilio Sync Service. If it's a change in the status property of the open orders List it will automatically trigger the below actions.

The code for this can be found in the sync webhook file.

8. Webhook sends message to user

In the sync webhook file we will then send a message to the user using the Twilio Conversations REST API.

9. Order is removed from the queue

Once the message was sent, the entry will be removed from the open orders List and the entry of the customer in the Map will be updated to clear the openOrders array of the customer.