trigger-schedule

@objectstack/plugin-trigger-schedule

Auto-launch ObjectStack flows on a schedule (cron / interval / once).

The automation engine ships the FlowTrigger extension point and the wiring that turns a flow's start node into a normalized trigger binding — but the concrete schedule trigger lives here, as a plugin. It delegates timing to the platform IJobService (the 'job' service), so it stays adapter-agnostic: the job service selects a cron-capable adapter (e.g. the durable DbJobAdapter or CronJobAdapter) for cron schedules and the interval adapter for the rest.

This is the sibling of @objectstack/plugin-trigger-record-change — same engine baseline, a different event source.

What it does

A flow whose start node declares a schedule:

{
  type: 'start',
  config: {
    schedule: { type: 'cron', expression: '0 1 * * *', timezone: 'UTC' },
    condition: "...", // optional start-condition gate
  },
}
// or simply: a flow with `type: 'schedule'` and a start-node schedule descriptor

auto-launches on that schedule — no manual engine.execute(). When it fires, the flow runs with event: 'schedule' and params: { jobId, flowName, schedule } in its context.

Schedule shapes

normalizeSchedule accepts the canonical JobSchedule plus shorthands:

Input	Normalized
{ type: 'cron', expression, timezone? }	cron
'0 1 * * *' (bare string)	{ type: 'cron', expression: '0 1 * * *' }
{ cron } / { expression }	cron
{ type: 'interval', intervalMs } / { every }	interval
{ type: 'once', at } / { at }	once

Usage

import { AutomationServicePlugin } from '@objectstack/service-automation';
import { JobServicePlugin } from '@objectstack/service-job';
import { ScheduleTriggerPlugin } from '@objectstack/plugin-trigger-schedule';

kernel
  .use(new AutomationServicePlugin())  // engine + flows
  .use(new JobServicePlugin())         // the 'job' service (cron/interval/db)
  .use(new ScheduleTriggerPlugin());   // ← makes schedule flows live

Depends on the job service plugin (com.objectstack.service.job) so its kernel:ready adapter upgrade runs first; the job service is nonetheless resolved lazily per bind, so adapter upgrades are always picked up. If the automation or job service is unavailable, the plugin logs a warning and no-ops rather than failing startup.

Error isolation

A flow that throws during a scheduled run is logged and swallowed — it never crashes the job runner.

Time-relative trigger (TimeRelativeTriggerPlugin)

The declarative answer to "act on records whose date field is coming up (or overdue)" (#1874) — without the fragile date-equality-on-record-change pattern (which only fires if a record happens to be edited on the threshold day) or a hand-rolled cron + range query per flow.

A flow whose start node declares a timeRelative descriptor is swept on a schedule and launched once per matching record:

{
  type: 'start',
  config: {
    timeRelative: {
      object: 'contracts',
      dateField: 'end_date',
      offsetDays: [60, 30, 7],       // T-minus reminders — fires on each threshold day
      // — or — withinDays: 30       // "expiring soon" range (negative = overdue lookback)
      filter: { status: 'active' },  // optional, ANDed with the date window
      maxRecords: 1000,              // optional per-sweep cap (default 1000)
    },
    schedule: { type: 'cron', expression: '0 8 * * *' }, // optional; defaults to daily 08:00 UTC
    condition: '...',                // optional per-record start-condition gate
  },
}

The matched record rides on the automation context (event: 'time_relative', record, params), so the start-node condition gate and {record.<field>} interpolation work exactly as for a record-change flow. Because the window is evaluated every day, a threshold is never missed regardless of when the record last changed.

Mode	Semantics (day-granular, UTC, always includes today)
withinDays: N	dateField ∈ [today, today + N] (upcoming). N < 0 = overdue lookback.
offsetDays: [a,b]	one single-day match per offset (today + a, today + b, …).

It needs both the job service (sweep cadence) and the ObjectQL engine (the date-window query); register it alongside the schedule trigger:

import { ScheduleTriggerPlugin, TimeRelativeTriggerPlugin } from '@objectstack/plugin-trigger-schedule';

kernel
  .use(new ScheduleTriggerPlugin())      // plain schedule flows
  .use(new TimeRelativeTriggerPlugin());  // ← time-relative sweeps (needs the ObjectQL engine)

The discovery query runs as a system operation (RLS-bypassing — a background sweep sees all rows), is capped at maxRecords per tick (logged when it clamps), and isolates per-record failures so one bad row never aborts the sweep.