Class Trigger

The entry point for every workflow graph. Each graph must have exactly one trigger activity, which executes when the graph's subscribes topic receives a message (via hotMesh.pub or hotMesh.pubsub).

The trigger initializes the job, sets its unique ID and key, binds the incoming payload as the trigger's output data, and transitions to adjacent activities defined in the transitions section.

YAML Configuration

app:
  id: myapp
  version: '1'
  graphs:
    - subscribes: order.placed       # the trigger fires when this topic receives a message
      publishes: order.processed     # emitted when the graph completes
      expire: 120

      activities:
        t1:
          type: trigger
          entity: '{$self.input.data.entityType}'
          job:
            maps:
              myField: '{$self.output.data.inputField}'
          stats:
            id: '{$self.input.data.workflowId}'
            key: '{$self.input.data.parentId}'
            parent: '{$self.input.data.originJobId}'
            adjacent: '{$self.input.data.parentJobId}'

        process:
          type: worker
          topic: order.process

      transitions:
        t1:
          - to: process

Key Behaviors

Job ID Resolution: If stats.id is provided, it resolves via @pipe expressions against the input data. Otherwise a UUID is generated.
Duplicate Detection: If a job with the same ID already exists, a DuplicateJobError is thrown (unless it's a crash-recovery scenario).
Pending Mode: When invoked with { pending: <seconds> }, the trigger creates the job but does not transition to children until resumed.
Crash Recovery: Uses a 3-step inception protocol with GUID ledger to ensure atomic job creation survives process crashes.

See

TriggerActivity for the TypeScript interface

Hierarchy (view full)

Activity
- Trigger

Index

Constructors

constructor

Properties

adjacencyList adjacentIndex code config context data engine guidLedger hook leg logger metadata status

Constructors

constructor

new Trigger(config, data, metadata, hook, engine, context?): Trigger
Parameters
- config: ActivityType
- data: ActivityData
- metadata: ActivityMetadata
- hook: ActivityData
- engine: EngineService
- Optionalcontext: JobState
Returns Trigger
Inherited from Activity.constructor
- Defined in services/activities/activity/index.ts:86

Properties

adjacencyList

adjacencyList: StreamData[]

adjacentIndex

adjacentIndex: number = 0

code

code: number = 200

config

config: TriggerActivity

context

context: JobState

data

data: ActivityData

engine

engine: EngineService

guidLedger

guidLedger: number = 0

hook

hook: ActivityData

leg

leg: ActivityLeg

logger

logger: ILogger

metadata

metadata: ActivityMetadata

status

status: StreamStatus = StreamStatus.SUCCESS

Methods

assertGenerationalId

assertGenerationalId(jobGID, msgGID?): void
Reject stale messages from a prior job generation
Parameters
- jobGID: string
- OptionalmsgGID: string
Returns void
Inherited from Activity.assertGenerationalId
- Defined in services/activities/activity/index.ts:155

authorizeEntry

authorizeEntry(_state): string[]
Parameters
- _state: StringAnyType
Returns string[]
Inherited from Activity.authorizeEntry
- Defined in services/activities/activity/index.ts:340

bindActivityData

bindActivityData(type): void
Attach inbound data (output or hook) to the activity's context slot
Parameters
- type: "hook" | "output"
Returns void
Inherited from Activity.bindActivityData
- Defined in services/activities/activity/index.ts:219

bindActivityError

bindActivityError(data): void
Attach an error response to the activity's context slot
Parameters
- data: Record<string, unknown>
Returns void
Inherited from Activity.bindActivityError
- Defined in services/activities/activity/index.ts:224

bindActivityMetadata

bindActivityMetadata(): void
Stamp activity-level timestamps, type, and subtype

Returns void
Inherited from Activity.bindActivityMetadata
- Defined in services/activities/activity/index.ts:199

bindActivityMetadataPaths

bindActivityMetadataPaths(): string[]
Activity metadata paths to persist (Trigger overrides; leg-aware)

Returns string[]
Overrides Activity.bindActivityMetadataPaths
- Defined in services/activities/trigger.ts:361

bindActivityState

bindActivityState(state): void
Flatten activity-level context paths into store-ready key/values
Parameters
- state: StringAnyType
Returns void
Inherited from Activity.bindActivityState
- Defined in services/activities/activity/index.ts:209

bindDimensionalAddress

bindDimensionalAddress(state): void
Write the dimensional address into the state payload
Parameters
- state: StringAnyType
Returns void
Inherited from Activity.bindDimensionalAddress
- Defined in services/activities/activity/index.ts:214

bindJobError

bindJobError(data): void
Promote an unhandled activity error to the job level
Parameters
- data: Record<string, unknown>
Returns void
Inherited from Activity.bindJobError
- Defined in services/activities/activity/index.ts:229

bindJobMetadata

bindJobMetadata(): void
Stamp job-level ju (job_updated) timestamp

Returns void
Inherited from Activity.bindJobMetadata
- Defined in services/activities/activity/index.ts:194

bindJobMetadataPaths

bindJobMetadataPaths(): string[]
Job metadata paths to persist (Trigger overrides with full JOB set)

Returns string[]
Overrides Activity.bindJobMetadataPaths
- Defined in services/activities/trigger.ts:357

bindJobState

bindJobState(state): Promise<void>
Flatten job-level context paths into store-ready key/values
Parameters
- state: StringAnyType
Returns Promise<void>
Inherited from Activity.bindJobState
- Defined in services/activities/activity/index.ts:204

bindMarkerData

bindMarkerData(options?): void
Parameters
- Optionaloptions: ExtensionType
Returns void
Overrides Activity.bindMarkerData
- Defined in services/activities/trigger.ts:252

bindSearchData

bindSearchData(options?): void
Parameters
- Optionaloptions: ExtensionType
Returns void
Overrides Activity.bindSearchData
- Defined in services/activities/trigger.ts:244

createInputContext

createInputContext(): Partial<JobState>
Returns Partial<JobState>
- Defined in services/activities/trigger.ts:288

execAdjacentParent

execAdjacentParent(): Promise<void>
if the parent (spawner) chose not to await, emit the job_id as the data payload { job_id }

Returns Promise<void>
- Defined in services/activities/trigger.ts:270

executeLeg1StepProtocol

executeLeg1StepProtocol(delta): Promise<boolean>
Leg 1 protocol: save → spawn → complete (Category B activities)
Parameters
- delta: number
Returns Promise<boolean>
Inherited from Activity.executeLeg1StepProtocol
- Defined in services/activities/activity/index.ts:314

executeStepProtocol

executeStepProtocol(delta, shouldFinalize): Promise<boolean>
Leg 2 protocol: save → spawn → complete (duplex activities)
Parameters
- delta: number
- shouldFinalize: boolean
Returns Promise<boolean>
Inherited from Activity.executeStepProtocol
- Defined in services/activities/activity/index.ts:309

filterAdjacent

filterAdjacent(): Promise<StreamData[]>
Build the list of child activities to transition to

Returns Promise<StreamData[]>
Inherited from Activity.filterAdjacent
- Defined in services/activities/activity/index.ts:258

getJobStatus

getJobStatus(): number
Returns number
Overrides Activity.getJobStatus
- Defined in services/activities/trigger.ts:371

getState

getState(): Promise<void>
Load job state from the store into this.context

Returns Promise<void>
Overrides Activity.getState
- Defined in services/activities/trigger.ts:301

getTriggerConfig

getTriggerConfig(): Promise<ActivityType>
Returns Promise<ActivityType>
Inherited from Activity.getTriggerConfig
- Defined in services/activities/activity/index.ts:354

handleProcessError

handleProcessError(error, telemetry, label): void
Parameters
- error: Error
- telemetry: TelemetryService
- label: string
Returns void
Inherited from Activity.handleProcessError
- Defined in services/activities/activity/index.ts:367

initDimensionalAddress

initDimensionalAddress(dad): void
Set the dimensional address for this activity
Parameters
- dad: string
Returns void
Inherited from Activity.initDimensionalAddress
- Defined in services/activities/activity/index.ts:150

initPolicies

initPolicies(ctx): void
Resolve expire and persistent policies from config
Parameters
- ctx: JobState
Returns void
Inherited from Activity.initPolicies
- Defined in services/activities/activity/index.ts:145

initSelf

initSelf(ctx): JobState
Bootstrap $self, $job refs and output.metadata.au timestamp
Parameters
- ctx: StringAnyType
Returns JobState
Inherited from Activity.initSelf
- Defined in services/activities/activity/index.ts:140

initStatus

initStatus(options?, count): number
pending flows will not transition from the trigger to adjacent children until resumed
Parameters
- options: ExtensionType = {}
- count: number
Returns number
- Defined in services/activities/trigger.ts:229

isJobComplete

isJobComplete(s): boolean
Parameters
- s: number
Returns boolean
Inherited from Activity.isJobComplete
- Defined in services/activities/activity/index.ts:292

jobWasInterrupted

jobWasInterrupted(s): boolean
Parameters
- s: number
Returns boolean
Inherited from Activity.jobWasInterrupted
- Defined in services/activities/activity/index.ts:296

mapInputData

mapInputData(): void
Map data INTO this activity (from other activities' outputs)

Returns void
Inherited from Activity.mapInputData
- Defined in services/activities/activity/index.ts:167

mapJobData

mapJobData(): void
Promote activity data to the shared job state via job.maps

Returns void
Inherited from Activity.mapJobData
- Defined in services/activities/activity/index.ts:177

mapOutputData

mapOutputData(): void
Transform this activity's own output via output.maps

Returns void
Inherited from Activity.mapOutputData
- Defined in services/activities/activity/index.ts:172

mapStatusThreshold

mapStatusThreshold(): number
Resolve the Dynamic Activation Control threshold (default: 0)

Returns number
Inherited from Activity.mapStatusThreshold
- Defined in services/activities/activity/index.ts:182

process

process(options?): Promise<string>
Parameters
- Optionaloptions: ExtensionType
Returns Promise<string>
- Defined in services/activities/trigger.ts:81

processEvent

processEvent(status?, code?, type?): Promise<void>
Parameters
- status: StreamStatus = StreamStatus.SUCCESS
- code: number = 200
- type: "hook" | "output" = 'output'
Returns Promise<void>
Inherited from Activity.processEvent
- Defined in services/activities/activity/index.ts:325

registerTimeout

registerTimeout(): Promise<void>
Returns Promise<void>
Inherited from Activity.registerTimeout
- Defined in services/activities/activity/index.ts:338

resolveAdjacentDad

resolveAdjacentDad(): string
Dimensional address for children (appends seed ,0)

Returns string
Inherited from Activity.resolveAdjacentDad
- Defined in services/activities/activity/index.ts:268

resolveDad

resolveDad(): string
Current dimensional address (accounts for cycle offset)

Returns string
Inherited from Activity.resolveDad
- Defined in services/activities/activity/index.ts:263

resolveGranularity

resolveGranularity(): string
Returns string
- Defined in services/activities/trigger.ts:365

resolveJobId

resolveJobId(context): string
Parameters
- context: Partial<JobState>
Returns string
- Defined in services/activities/trigger.ts:375

resolveJobKey

resolveJobKey(context): string
Parameters
- context: Partial<JobState>
Returns string
- Defined in services/activities/trigger.ts:380

resolveStatus

resolveStatus(multi): number
Extract the job status from the last transaction result
Parameters
- multi: TransactionResultList
Returns number
Inherited from Activity.resolveStatus
- Defined in services/activities/activity/index.ts:278

resolveThresholdHit

resolveThresholdHit(results): boolean
Did the semaphore reach its threshold? (from transaction results)
Parameters
- results: TransactionResultList
Returns boolean
Inherited from Activity.resolveThresholdHit
- Defined in services/activities/activity/index.ts:273

safeKey

safeKey(key): string
Parameters
- key: string
Returns string
- Defined in services/activities/trigger.ts:240

setExpired

setExpired(seconds, transaction): Promise<void>
Parameters
- seconds: number
- transaction: ProviderTransaction
Returns Promise<void>
- Defined in services/activities/trigger.ts:236

setLeg

setLeg(leg): void
Parameters
- leg: ActivityLeg
Returns void
Inherited from Activity.setLeg
- Defined in services/activities/activity/index.ts:337

setState

setState(txn?): Promise<string>
Persist the full activity + job state in a single store call
Parameters
- Optionaltxn: ProviderTransaction
Returns Promise<string>
Inherited from Activity.setState
- Defined in services/activities/activity/index.ts:241

setStats

setStats(transaction?): Promise<void>
Parameters
- Optionaltransaction: ProviderTransaction
Returns Promise<void>
- Defined in services/activities/trigger.ts:385

setStatus

setStatus(amount): Promise<void>
Increment/decrement the job semaphore
Parameters
- amount: number
Returns Promise<void>
Overrides Activity.setStatus
- Defined in services/activities/trigger.ts:262

shouldEmit

shouldEmit(): boolean
Should this activity emit to the graph's publishes topic?

Returns boolean
Inherited from Activity.shouldEmit
- Defined in services/activities/activity/index.ts:283

shouldPersistJob

shouldPersistJob(): boolean
Should this activity emit completion while keeping the job alive?

Returns boolean
Inherited from Activity.shouldPersistJob
- Defined in services/activities/activity/index.ts:288

verifyEntry

verifyEntry(): Promise<void>
Leg 1 entry for duplex activities (Worker, Await, Cycle)

Returns Promise<void>
Inherited from Activity.verifyEntry
- Defined in services/activities/activity/index.ts:112

verifyLeg1Entry

verifyLeg1Entry(): Promise<boolean>
Leg 1 entry for Category B (Hook passthrough, Signal, Interrupt-target). Returns true when resuming from a prior crash (Leg1 already committed).

Returns Promise<boolean>
Inherited from Activity.verifyLeg1Entry
- Defined in services/activities/activity/index.ts:123

verifyReentry

verifyReentry(): Promise<number>
Leg 2 re-entry for duplex activities; returns the activity ledger

Returns Promise<number>
Inherited from Activity.verifyReentry
- Defined in services/activities/activity/index.ts:117

Class Trigger

YAML Configuration

Key Behaviors

See

Hierarchy (view full)

Index

Constructors

Properties

Methods

Constructors

constructor

Parameters

Returns Trigger

Properties

adjacencyList

adjacentIndex

code

config

context

data

engine

guidLedger

hook

leg

logger

metadata

status

Methods

assertGenerationalId

Parameters

Returns void

authorizeEntry

Parameters

Returns string[]

bindActivityData

Parameters

Returns void

bindActivityError

Parameters

Returns void

bindActivityMetadata

Returns void

bindActivityMetadataPaths

Returns string[]

bindActivityState

Parameters

Returns void

bindDimensionalAddress

Parameters

Returns void

bindJobError

Parameters

Returns void

bindJobMetadata

Returns void

bindJobMetadataPaths

Returns string[]

bindJobState

Parameters

Returns Promise<void>

bindMarkerData

Parameters

Returns void

bindSearchData

Parameters

Returns void

createInputContext

Returns Partial<JobState>

execAdjacentParent

Returns Promise<void>

executeLeg1StepProtocol

Parameters

Returns Promise<boolean>

executeStepProtocol

Parameters

Returns Promise<boolean>

filterAdjacent

Returns Promise<StreamData[]>

getJobStatus

Returns number