initializePollingTracker()

initializePollingTracker<R, T>(config): void

Defined in: packages/pulsar-core/src/utils/initializePollingTracker.ts:172 

Starts polling a transaction in the background and returns immediately. Does nothing if tx.pending is false.

Every pollingInterval milliseconds (the first attempt also waits; a function is asked before each wait) it calls fetcher. Polling continues until the fetcher calls stopPolling. A fetcher that throws counts as a failed attempt; after maxRetries consecutive failed attempts the tracker calls onFailure() without arguments, logs a warning and stops (which calls removeTxFromPool, if configured), or, with retryForeverEveryMs, keeps asking at that delay. A successful attempt resets the count. A FinalPollingError ends it at once. An error thrown by a callback is logged and is not a failed attempt, as the fetcher would then report the same result again on the next tick.

Side effects: runs a timer loop until it is stopped; from the outside only isAbandoned can end it.

Type Parameters

R

R

The response type the fetcher reports.

T

T extends Pick<Transaction, "pending" | "txKey">

The tracked transaction type.

Parameters

config

PollingTrackerConfig<R, T>

The transaction, the fetcher and the callbacks.

Returns

void

Example

initializePollingTracker<string, { txKey: string; pending: boolean }>({
  tx: { txKey: taskId, pending: true },
  fetcher: async ({ tx, stopPolling, onSuccess, onFailure }) => {
    const status = await getTaskStatus(tx.txKey); // your API call; throw on network errors
    if (status === 'done') onSuccess(status);
    if (status === 'failed') onFailure(status);
    if (status !== 'pending') stopPolling({ withoutRemoving: true });
  },
  onSuccess: () => console.log('Done'),
  onFailure: () => console.log('Failed'),
});