Class: Context
activity.Context
Activity Context, used to:
- Get Info about the current Activity Execution
- Send heartbeats
- Get notified of Activity cancellation
- Sleep (cancellation-aware)
Call Context.current() from Activity code in order to get the current Activity's Context.
Properties
cancellationSignal
• Readonly cancellationSignal: AbortSignal
An AbortSignal that can be used to react to
Activity cancellation.
Used by fetch to abort an in-progress request and child_process to abort a child process, and is supported by some other libraries as well.
See
cancelled
• Readonly cancelled: Promise<never>
Await this promise in an Activity to get notified of cancellation.
This promise will never resolve—it will only be rejected with a CancelledFailure.
See
info
• info: Info
Holds information about the current executing Activity.
Methods
heartbeat
▸ heartbeat(details?): void
Send a heartbeat from an Activity.
If an Activity times out, then during the next retry, the last value of details is available at
heartbeatDetails. This acts as a periodic checkpoint mechanism for the progress of an Activity.
If an Activity times out on the final retry (relevant in cases in which RetryPolicy.maximumAttempts is
set), the Activity function call in the Workflow code will throw an ActivityFailure with the cause
attribute set to a TimeoutFailure, which has the last value of details available at
TimeoutFailure.lastHeartbeatDetails.
Calling heartbeat() from a Local Activity has no effect.
Activities must heartbeat in order to receive Cancellation (unless they're Local Activities, which don't need to).
Parameters
| Name | Type |
|---|---|
details? | unknown |
Returns
void
sleep
▸ sleep(ms): Promise<void>
Helper function for sleeping in an Activity.
Parameters
| Name | Type | Description |
|---|---|---|
ms | string | number | Sleep duration: number of milliseconds or ms-formatted string |
Returns
Promise<void>
A Promise that either resolves when ms is reached or rejects when the Activity is cancelled
current
▸ Static current(): Context
Gets the context of the current Activity.
Uses AsyncLocalStorage under the hood to make it accessible in nested callbacks and promises.