contract.on() to fire after a number of confirmations. How to do it?

[mudgen]

Hello, I'd like to use the contract.on() API to capture an event that occurs after 20 confirmations. Is there a way to do this?

[ricmoo]

Specifying the number of confirmations to the EventEmitter API isn't possible, but I think you should be able to do:

// Depending on the number of arguments you have...
contract.on(filter, async (arg0, arg1, event) => {
  const receipt = await event.getTransactionReceipt();
  await contract.provider.waitForTransaction(receipt.transactionHash, 20);
  do_stuff_here();
});

In v6, it would make sense for me to add a .wait to the event object... I'll add it to my list. :)

[xtrinch]

Will this block execution of my other code? I'd like the server to do other stuff in the mean time while it waits for confirmations

[ricmoo]

No, that’s not how an event emitter works, and the listener is using async/await. The event loop will yield on the await until the correct number of confirmations.

[mudgen]

Great, thank you!

[ricmoo]

(migrating to discussions)