Emit

Purpose

The Emit task allows workflows to publish CloudEvents to event brokers or messaging systems.

This facilitates communication and coordination between different components and services. With the Emit task, workflows can seamlessly integrate with event-driven architectures, enabling real-time processing, event-driven decision-making, and reactive behavior based on external systems consuming these events.

Usage Example

document:
  dsl: '1.0.0' # Assuming alpha5 or later based on reference example
  namespace: test
  name: emit-example
  version: '0.1.0'
use:
  secrets:
    - orderServiceApiKey
  authentications:
    orderServiceAuth:
      bearer:
        token: ${ $secrets.orderServiceApiKey }
do:
  - placeOrder:
      call: http
      with:
        method: POST
        endpoint:
          uri: "http://orders-service/api/v1/orders"
          authentication:
            use: orderServiceAuth
        headers:
          Content-Type: "application/json"
        body:
          customerId: ${ .customerId }
          items: ${ .items }
      output:
        as: orderResult
      then: emitOrderPlacedEvent
      catch:
        errors:
          with:
            type: "*"
        then: handleOrderError
  - emitOrderPlacedEvent:
      emit:
        event:
          with:
            source: "https://petstore.com/orders"
            type: "com.petstore.order.placed.v1"
            subject: "${ .orderResult.orderId }"
            data:
              client:
                firstName: "${ $context.customer.first }"
                lastName: "${ $context.customer.last }"
              orderId: "${ .orderResult.orderId }"
              items: "${ .orderResult.items }"
      output:
        as: eventResult
  - handleOrderError:
      emit:
        event:
          with:
            source: "https://petstore.com/orders"
            type: "com.petstore.order.error.v1"
            subject: "order-error"
            data:
              error: "${ .error.message }"
              customerId: "${ .customerId }"