Some watched events randomly don't show up

[tronprotocol]

Some watched events randomly don't show up

[UnforgivenZZZ]

@forhas
we all left tron so maybe don't expected those issue to be fixed

[ColonelJ]

In case it might help anyone, this is the code I'm using instead of using contract.Method().watch to discover the events due to this problem (seems to work reliably for recent events).

(Note that the 60 seconds on the first line is to allow for the fact that the newly loaded events will have timestamps in the past, and when onlyConfirmed is on, this gap will include the time it takes for the transaction to confirm on the solidity node. Even without onlyConfirmed there should still be at least 3 seconds because of waiting for the interval to trigger and this is also the maximum time since the previous block was mined.)

    let last_event_timestamp = Date.now() - 60000;
    let processing = false;
    setInterval(async () => {
        if (processing) return;
        processing = true;
        try {
            let events = [];
            let more_events =
                await tronWeb.getEventResult(CONTRACT_ADDRESS, {
                    onlyConfirmed: true,
                    sinceTimestamp: last_event_timestamp + 1,
                    sort: 'block_timestamp'
                });
            while (more_events.length
                   && more_events[more_events.length - 1].fingerprint) {
                events = events.concat(more_events);
                more_events =
                    await tronWeb.getEventResult(CONTRACT_ADDRESS, {
                        onlyConfirmed: true,
                        previousLastEventFingerprint:
                            more_events[more_events.length - 1].fingerprint,
                        sort: 'block_timestamp'
                    });
            }
            events = events.concat(more_events);
            if (events.length) {
                last_event_timestamp = events[events.length - 1].timestamp;
                for (let i = 0; i < events.length; ++i) {
                    if (events[i].name == 'Method') {
                        /*...*/
                    } else if (events[i].name == /*...*/) {
                        /*...*/
                    /*...*/
                    } else {
                        console.error('Unrecognized event name:', events[i].name);
                    }
                }
            }
        } catch (err) {
            console.error('Error getting events:', err);
        }
        processing = false;
    }, 3000);

This also has the advantage that it only does one request for all possible events that can be emitted by the contract. If you wanted you could add the eventName parameter to the options for getEventResult so you wouldn't have to check the name.

Maybe the contract.Method().watch functionality could use logic similar to this to achieve the desired effect.

[sullof]

If you want to be sure you get all the events in a block, you can use TronGridJS API and retrieve the events by block. Look at https://github.com/TRON-US/trongrid-js/blob/master/test/unit/lib/block.test.js for examples.

[sullof]

To solve the issue we will add web sockets in the future.

[sullof]

I'll take a look at your code.

[forhas]

Hi @sullof,
Do you know if this one is expected to be resolved anytime soon?

[forhas]

@UnforgivenZZZ thanks for clarifying.
Is the project still maintained (by anyone)?

[sullof]

It looks like last merge was 21 days ago by @jeancky.

[tigfamon]

@sullof , @forhas is there any update on this issue? For our poker game, event listening is still not working correctly. Some events get lost.

[pryctoyogi]

@tigfamon I did not get the chance to test the latest version.
I've implemented my own manual solution:

setInterval(getEvents, tronBlockTime * pullCycle);

async function getEvents() {
    if (isRunning) {
        return;
    }
    isRunning = true;
    try {
        const latestBlock = await tronWeb.trx.getBlock('latest');
        let start = latestEventsBlockNumber;
        let end = latestBlock.block_header.raw_data.number;
        const eventsArr = [];
        for (let i = start; i < end; i++) {
            eventsPullingOptions.block_number = i;
            const events = await tronGrid.contract.getEvents(playzaContractAddress, eventsPullingOptions);
            const blockEvents = await events.data;
            if (blockEvents && blockEvents.length > 0) {
                eventsArr.push(...blockEvents);
            }
        }
        latestEventsBlockNumber = end;
        handleEvents(eventsArr);
    } catch (err) {
        // handle errors
        }
    } finally {
        isRunning = false;
    }
}

[002love]

@sullof bro, is the problem still not fixed? Can you please correct this misunderstanding, this is a lot of problems 😔