Getting timestamps in deterministic way in Hyperledger Composer transactions

Question

Is there a deterministic way to get timestamp in transaction function, similar to stub.GetTxTimestamp() that can be used in Go version of Fabric's chaincode.

score 3 · Accepted Answer · answered Apr 28 '17 at 04:58

Just sharing an example that works with basic-sample-network network:

In the model file (lib/org.acme.sample.cto) I extended SampleAsset definition any added new property called timestamp of type DateTime:

asset SampleAsset identified by assetId {
  o String assetId
  --> SampleParticipant owner
  o String value
  o DateTime timestamp
}

In the script file (lib/logic.js), the onSampleTransaction function to update SampleAsset's timestamp with current transaction's timestamp:

function onSampleTransaction(sampleTransaction) {
  sampleTransaction.asset.value = sampleTransaction.newValue;
  sampleTransaction.asset.timestamp = sampleTransaction.timestamp;
  return getAssetRegistry('org.acme.sample.SampleAsset')
       .then(function (assetRegistry) {
               return assetRegistry.update(sampleTransaction.asset);
        });
}

But it's possible that some malevolent or malfunctioning node could stamp a wrong timestamp? — TortelliEngineer, Nov 28 '18 at 06:10

score 1 · Answer 2 · answered Apr 27 '17 at 13:07

1

All transactions have a system property called timestamp, so you can use myTransaction.timestamp.

answered Apr 27 '17 at 13:07

Dan Selman

2,287
2
9
18

Thanks a lot for response, Dan! Here is the sample that works for basic-sample-network (assuming that asset "SampleAsset" has the property called "timestamp" that we want to update with the following transaction "SampleTransaction"): `function onSampleTransaction(sampleTransaction) { sampleTransaction.asset.value = sampleTransaction.newValue; sampleTransaction.asset.timestamp = sampleTransaction.timestamp; return getAssetRegistry('org.acme.sample.SampleAsset') .then(function (assetRegistry) { return assetRegistry.update(sampleTransaction.asset); }); }` – Nikolay Vlasov Apr 28 '17 at 04:44
https://github.com/hyperledger-archives/fabric/issues/1832 we cannot use the proto from the vendor folder ... – Benjamin Fuentes Feb 08 '18 at 14:46

score 0 · Answer 3 · answered Feb 08 '18 at 14:47

0

we cannot use the proto from the vendor folder ...

https://github.com/hyperledger-archives/fabric/issues/1832

answered Feb 08 '18 at 14:47

Benjamin Fuentes

674
9
22

Getting timestamps in deterministic way in Hyperledger Composer transactions

3 Answers3

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