Sample App Namespace Schema

Let's start by checking the namespace schema of the sample application.

JSON

{
  "$namespace": "gallifrey-rules-sample",
  "$modulesPaths": [
    "$",
    "/app/modules"
  ],
  "$entities": {
    "orders": {
      "new-order": {
        "$rules": [
          "notify-customer-new-order-rule"
        ]
      }
    }
  },
  "$consumers": [
    {
      "name": "new-orders-consumer",
      "type": "kafka",
      "eventDispatcher": "new-order-dispatcher",
      "config": {
        "groupId": "group-id-1",
        "topics": "new-orders",
        "fromBeginning": true
      }
    }
  ]
}

YAML

$namespace: gallifrey-rules-sample
$modulesPaths:
  - $
  - /app/modules
$entities:
  orders:
    new-order:
      $rules:
        - notify-customer-new-order-rule
$consumers:
- name: new-orders-consumer
  type: kafka
  eventDispatcher: new-order-dispatcher
  config:
    groupId: group-id-1
    topics: new-orders
    fromBeginning: true

Let's break this down:

• $namespace: is your namespace, this uniquely identifies the instance of your engine. Usually you have one namespace per project.
• $modulesPaths: is a list of directories that the engine loads all modules from. The '$' path is a special path that will get the engine to load modules that come with the library itself. In the application example you can see that all of it's modules live under modules folder.
• $entities: is your list of entities. Learn more. Under each entity, is the list of event names. and under each event name is your rules. In this example we have a single entity orders. For orders, we have a single event called new-order. And When we get the event new-order of entity orders, we run the single rule notify-customer-new-order-rule
• $consumers: is your list of consumers. Usually you should have at least one. In this example, we have a single consumer named new-orders-consumer, of type kafka. It's event dispatcher is new-order-dispatcher. The dispatcher code lives here. If you check the code you can see how the kafka message comes in and how we translate it into a Gallifrey Rules event.
• Under each consumer you have a config which might be different for different types of consumers. In this example, it's of type interface KafkaConsumerConfig