How do I get all logs for all time for a given contract using web3?

Question

This answer worked when filter.get was not deprecated, but now I am not sure how to do the same thing with subscribe - web3.eth.subscribe hears new events and acts on them after I create the subscription, but I am not sure how to get old events.

Answer 1

Try this (tested with web3.js v1.2.1):

async function getPastLogs(address, fromBlock, toBlock) {
    if (fromBlock <= toBlock) {
        try {
            const options = {
                address  : address,
                fromBlock: fromBlock,
                toBlock  : toBlock
            };
            return await web3.eth.getPastLogs(options);
        }
        catch (error) {
            const midBlock = (fromBlock + toBlock) >> 1;
            const arr1 = await getPastLogs(address, fromBlock, midBlock);
            const arr2 = await getPastLogs(address, midBlock + 1, toBlock);
            return [...arr1, ...arr2];
        }
    }
    return [];
}

...

const latest = await web3.eth.getBlock("latest");
const logs = await getPastLogs(yourContractAddress, 1, latest);

You can further optimize this by replacing 1 with your contract creation block number.

See more on function web3.eth.getPastLogs here.