scheduled()
Background
When a Worker is invoked via a Cron Trigger, the scheduled() handler handles the invocation.
Syntax
export default { async scheduled(event, env, ctx) { ctx.waitUntil(doSomeTaskOnASchedule()); },
};
Properties
event.cronstring- The value of the Cron Trigger that started the
ScheduledEvent.
- The value of the Cron Trigger that started the
event.typestring- The type of event. This will always return
"scheduled".
- The type of event. This will always return
event.scheduledTimenumber- The time the
ScheduledEventwas scheduled to be executed in milliseconds since January 1, 1970, UTC. It can be parsed asnew Date(event.scheduledTime).
- The time the
envobject- An object containing the bindings associated with your Worker using ES modules format, such as KV namespaces and Durable Objects.
ctxobject- An object containing the context associated with your Worker using ES modules format. Currently, this object just contains the
waitUntilfunction.
- An object containing the context associated with your Worker using ES modules format. Currently, this object just contains the
Methods
When a Workers script is invoked by a Cron Trigger, the Workers runtime starts a ScheduledEvent which will be handled by the scheduled function in your Workers Module class. The ctx argument represents the context your function runs in, and contains the following methods to control what happens next:
ctx.waitUntil(promisePromise):void- Use this method to notify the runtime to wait for asynchronous tasks (for example, logging, analytics to third-party services, streaming and caching). The first
ctx.waitUntilto fail will be observed and recorded as the status in the Cron Trigger Past Events table. Otherwise, it will be reported as a success.
- Use this method to notify the runtime to wait for asynchronous tasks (for example, logging, analytics to third-party services, streaming and caching). The first