Events

Event steps allow flows to publish business events that can trigger other processes through the publish-subscribe pattern.

Publish Event

Raises a business event that can trigger event handlers.

Parameter	Description
Event Definition	The event type to publish
Event Properties Binding	Mapping of values to event properties

When an event is published:

1. An immutable event instance is created
2. All synchronous handlers execute immediately (in order)
3. Asynchronous handlers are queued for background execution
4. The flow continues after synchronous handlers complete

Example - Simple Event:

PUBLISH EVENT
  Event Definition: OrderPlaced
  Event Properties Binding:
    OrderId: Order.Id
    CustomerId: Order.CustomerId
    OrderNumber: Order.OrderNumber
    TotalAmount: Order.TotalAmount
    OrderDate: NOW()

Example - Event with Calculated Properties:

# First calculate some values
RUN LOGIC BLOCK
  Logic Block: CalculateOrderMetrics
  Inputs: Order
  → Outputs: IsHighValue, IsFirstOrder, CustomerLifetimeValue

# Then publish event with all data
PUBLISH EVENT
  Event Definition: OrderCompleted
  Event Properties Binding:
    OrderId: Order.Id
    CustomerId: Order.CustomerId
    TotalAmount: Order.TotalAmount
    IsHighValue: IsHighValue
    IsFirstOrder: IsFirstOrder
    CustomerLifetimeValue: CustomerLifetimeValue
    CompletedDate: NOW()
    ProcessedBy: CurrentUser.Id

Event Patterns

Workflow Completion Events

Publish events when significant workflow milestones are reached:

# At the end of an order processing flow

CONDITION: Order Fully Processed?
  Condition: AllStepsSuccessful == true
  
  TRUE BRANCH:
    PUBLISH EVENT
      Event Definition: OrderProcessingCompleted
      Event Properties Binding:
        OrderId: Order.Id
        ProcessingDuration: DATEDIFF(StartTime, NOW())
        ItemsProcessed: ProcessedCount
        Status: "Success"
  
  FALSE BRANCH:
    PUBLISH EVENT
      Event Definition: OrderProcessingFailed
      Event Properties Binding:
        OrderId: Order.Id
        FailureReason: ErrorMessage
        FailedAtStep: FailedStepName
        Status: "Failed"

Entity Lifecycle Events

Publish events at key points in an entity's lifecycle:

# Customer Onboarding Flow

# After initial setup
PUBLISH EVENT
  Event Definition: CustomerCreated
  Event Properties Binding:
    CustomerId: Customer.Id
    CustomerName: Customer.Name
    CreatedBy: CurrentUser.Id

# ... additional onboarding steps ...

# After onboarding complete
PUBLISH EVENT
  Event Definition: CustomerOnboarded
  Event Properties Binding:
    CustomerId: Customer.Id
    OnboardingDuration: DATEDIFF(Customer.CreatedOn, NOW())
    AssignedAccountManager: Customer.AccountManagerId

Integration Events

Publish events when external system interactions complete:

# After payment processing
CALL REST API
  Service Connection: PaymentGateway
  Operation: ProcessPayment
  → PaymentResult

PUBLISH EVENT
  Event Definition: PaymentProcessed
  Event Properties Binding:
    OrderId: Order.Id
    PaymentAmount: Order.TotalAmount
    TransactionId: PaymentResult.TransactionId
    PaymentMethod: SelectedMethod
    Success: PaymentResult.Status == "approved"
    ProcessedAt: NOW()

Batch Processing Events

Publish events during and after batch operations:

# Batch processing flow
NEW VARIABLE: ProcessedCount = 0
NEW VARIABLE: ErrorCount = 0

ITERATOR: Process Records
  Collection: RecordsToProcess
  Item Variable: Record
  
  Steps:
    # Process each record...
    
    # Publish progress event periodically
    CONDITION: Should Report Progress?
      Condition: ProcessedCount % 100 == 0
      
      TRUE BRANCH:
        PUBLISH EVENT
          Event Definition: BatchProgressUpdate
          Event Properties Binding:
            BatchId: BatchJob.Id
            ProcessedCount: ProcessedCount
            TotalCount: TotalRecords
            PercentComplete: (ProcessedCount / TotalRecords) * 100

# After batch completes
PUBLISH EVENT
  Event Definition: BatchCompleted
  Event Properties Binding:
    BatchId: BatchJob.Id
    TotalProcessed: ProcessedCount
    ErrorCount: ErrorCount
    Duration: DATEDIFF(BatchStartTime, NOW())

Best Practices

Publish at Business Moments: Events should represent meaningful business occurrences, not technical operations. "OrderPlaced" is better than "RecordSaved".

Include Sufficient Context: Event properties should contain enough information for handlers to do their work without additional queries.

Keep Events Focused: Each event should represent one thing that happened. Don't combine multiple events into one.

Consider Handler Execution: Remember that synchronous handlers block the publishing flow. Keep synchronous handlers fast and move heavy processing to asynchronous handlers.

Don't Rely on Handler Success: The publishing flow should not depend on what handlers do. Handlers may fail independently.

Avoid Circular Events: Be careful not to create event chains where handlers publish events that trigger the original flow.

Document Event Contracts: Clearly document when each event is published and what properties it provides so handler developers know what to expect.

Event Handlers

Events by themselves don't do anything - they need Event Handlers to respond to them. See Event documentation for details on creating Event Definitions and Event Handlers.