5

I have a smart contract with an event.

    event NewContractCreated(address _callerAddress, address _newContractAddress);

I know how to actively listen for new events:

var newContractEvent = myContract.NewContractCreated();
newContractEvent.watch(function(error, result){
      if (!error){
        console.log("Success");
        console.log("New Contract Address: " + result.args._newContractAddress);
        console.log("Creator: " + result.args._callerAddress);
      }
  });

That works just fine for me. But my question is: how do I listen for and pull the exact same data for events that happened before I started watching?

I tried the exact same thing but using get instead of watch... it half worked. It printed the top line "Success" but did not print the rest of the log lines.

4

You should be able to specify the period (in block no) to watch. According the documentation here

fromBlock: Number|String - The number of the earliest block (latest may be given to mean the most recent and pending currently mining, block). By default latest.

toBlock: Number|String - The number of the latest block (latest may be given to mean the most recent and pending currently mining, block). By default latest.

In your case, that should work :

var newContractEvent = myContract.NewContractCreated();
newContractEvent.watch({fromBlock: 0, toBlock: 'latest'}, function(error, result){
      if (!error){
        console.log("Success");
        console.log("New Contract Address: " + result.args._newContractAddress);
        console.log("Creator: " + result.args._callerAddress);
      }
  });
1

Try

var newContractEvent = myContract.NewContractCreated({}, {fromBlock: 12345, toBlock: 'latest'});
newContractEvent.watch(function(error, result) {
    if (!error){
        console.log("Success");
        console.log("New Contract Address: " + result.args._newContractAddress);
        console.log("Creator: " + result.args._callerAddress);
        JSON.stringify(result);
    }
});

See How do I retrieve the Voted events from The DAO for further information on using your event's indexed parameters as filter elements.

0

My suggestion would be

  • Create a filter with options {fromBlock:.., toBlock:.., address:.Contract_addr.}
  • Then use filter.get() to receive events from the past
  • Consider caching of past events if you are using MetaMask or remote node

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