# Using Event API

#Overview of RabbitMQ Naming Convention

Applogic follows the naming conventions defined in Peatio and Barong. All the events produced by the servers can be listened by Applogic.

See Peatio docs here and Barong here

AppLogic submits all events into three exchanges depending on event category (read next).

The exchange name consists of three parts:

1) application name, like applogic, peatio, barong.

2) fixed keyword events.

3) category of event, like system (generic system event), model (the attributes of some record were updated), market (trading events), user (user events).

The routing key looks like transaction.success.

The event name matches the routing key but with event category appended at the beginning, like model.transaction.success.

#Creating event consumer

Event consumer should respond to call(event) and be defined at app/consumers.

Consumer class name must be defined as:

[Application name]::[Event category]::[Event name]Consumer

Example (at app/consumers/barong/model/account_created_consumer.rb):

# frozen_string_literal: true

module Barong
  module Model
    class AccountCreatedConsumer
      def call(event)
        token = event[:record][:confirmation_token]
        email = event[:record][:email]
        BarongMailer.verification_email(email, token).deliver_now
      end

      class << self
        def call(event)
          new.call(event)
        end
      end
    end
  end
end

You can replace Barong with Peatio, update event name so you can handle events from Peatio.

#Configuration

You need to set new variables:

  EVENT_API_RABBITMQ_URL: ~
  EVENT_API_RABBITMQ_HOST:     localhost
  EVENT_API_RABBITMQ_PORT:     '5672'
  EVENT_API_RABBITMQ_USERNAME: guest
  EVENT_API_RABBITMQ_PASSWORD: guest

  BARONG_EVENT_API_JWT_PUBLIC_KEY:        ~     # Mandatory.
  BARONG_EVENT_API_JWT_ALGORITHM:         RS256 # JWT signing algorithm (mandatory).
  BARONG_EVENT_API_JWT_ISSUER:            ~     # JWT issuer name (optional).
  BARONG_EVENT_API_JWT_AUDIENCE:          ~     # Optional.
  BARONG_EVENT_API_JWT_SUBJECT:           ~     # Optional.
  BARONG_EVENT_API_JWT_DEFAULT_LEEWAY:    ~     # Seconds (optional).
  BARONG_EVENT_API_JWT_ISSUED_AT_LEEWAY:  ~     # Seconds (optional).
  BARONG_EVENT_API_JWT_EXPIRATION_LEEWAY: ~     # Seconds (optional).
  BARONG_EVENT_API_JWT_NOT_BEFORE_LEEWAY: ~     # Seconds (optional).

#Running event listener

The event listener is defined as Rake task.

Use the next command to run event listener:

EVENT_API_APPLICATION=barong EVENT_API_EVENT_CATEGORY=model EVENT_API_EVENT_NAME=account.created bundle exec rake event_api_listener