createProcessManager

Process managers are created via eventStore.createProcessManager(name). They coordinate workflows across multiple aggregate roots by listening for events and issuing commands in response.

Creation

const pm = eventStore.createProcessManager('cascade-delete')

Builder Methods

.withState(state)

Defines optional internal state. The state is persisted alongside checkpoints and restored on catch-up.

pm.withState({ pendingDeletions: [] })

.withEventHandlers(handlers)

Registers event handlers named on{EventName}. If state was defined, accepts a callback receiving the state.

// Without state
pm.withEventHandlers({
  async onOrganizationDeleted({ streamId }) {
    const users = await db.select().from(usersTable)
      .where(eq(usersTable.orgId, streamId))
    for (const user of users) {
      userRoot.loadStream(user.id).delete()
    }
  },
})

// With state
pm.withEventHandlers((state) => ({
  async onUserCreated({ payload }) {
    state.userCount++
  },
}))

Each handler receives (event, { refreshing }) where refreshing is true during a refresh operation.

.withAfterEffects(handlers)

Registers handlers that run after all on{EventName} handlers have completed. Uses the after{EventName} naming convention.

pm.withAfterEffects({
  async afterOrderCompleted({ payload }) {
    await sendConfirmationEmail(payload.email)
  },
})

Tip

Use withAfterEffects when your handler depends on projections being up-to-date.

.concurrent()

Disables the default exclusive per-stream locking.

State Methods

Available only when .withState() has been called:

Method	Return Type	Description
.state()	Promise<State>	Returns current state after all pending events have been processed.
.refreshState()	Promise<void>	Full state refresh — replays all events from scratch.

Other Methods

.isReady()

Returns a promise that resolves when the process manager has finished its initial catch-up.

Context Helpers

import { isInsideProcessManager, getProcessManagerInfo } from '@requence/event-sourcing'

Function	Return Type	Description
isInsideProcessManager()	boolean	true if called within a process manager event handler.
getProcessManagerInfo()	{ name, event } | undefined	Returns the process manager name and triggering event.

Caution

The library detects infinite loops when a process manager listens for and emits the same event on the same stream. An InfiniteLoopError is thrown automatically.