Why using events instead of return value

[AlbertoSinigaglia]

Hi, at 8:06:00 you are using the events to log the requestId.. however, why can't we use something like this:

def main():
    contract = deployLottery()
    contract.setEntranceFee(1).wait(1)
    contract.startLottery({
        "from": getAccount()
    }).wait(1)
    fundWithLink(contract)
    tx = contract.endLottery({
        "from": getAccount()
    })
    tx.wait(1)
    print(tx.return_value)

I've tested it and it's passing:

def test_can_pick_winner_correctly():
    contract = deployLottery()
    contract.setEntranceFee(1).wait(1)
    contract.startLottery({
        "from": getAccount()
    }).wait(1)
    contract.enter({
        "from" : getAccount(),
        "value": contract.getEntranceFee()
    })
    contract.enter({
        "from" : getNotOwnerAccount(),
        "value": contract.getEntranceFee()
    })
    fundWithLink(contract)
    tx = contract.endLottery({
        "from": getAccount()
    })
    assert tx.events["RequestedRandomness"]["requestId"] == tx.return_value

[PatrickAlphaC]

You're 100% right here. I'll add this to the issues that we could have used this instead of events! This was a bit of an oversight of my end to not include return_value. Literally after I shipped the video I went "omg... I forgot return value". Thanks for calling it out!

Using events like we did is still a really good best practice so people can index what happens in our smart contracts.

[AlbertoSinigaglia]

yes sure, thank you again for the amazing work you're doing!