0

I generate my datum like so:

// Build datum
const sellerAddressPKH = changeAddressValue.slice(2,58);
const datumFields = CSL.PlutusList.new();
datumFields.add(CSL.PlutusData.new_integer(CSL.BigInt.from_str( ... )));
const datumConstr = CSL.ConstrPlutusData.new(
    CSL.BigNum.from_str('0'),
    datumFields
);
const datum = CSL.PlutusData.new_constr_plutus_data(datumConstr);
const datumHash = CSL.hash_plutus_data(datum);

Part of the output where I am sending native asset into a smart contract, I am attaching the datum hash like so:

txBuilder.add_output(
    CSL.TransactionOutputBuilder
        .new()
        .with_address(scriptAddress)
        .with_data_hash(datumHash)
        .next()
        .with_asset_and_min_required_coin(
            multiAsset,
            CSL.BigNum.from_str(protocolParameters.costPerWord.toString())
        )
        .build()
);

This only appears to be attaching the datum hash, and I cannot easily see how you would attach the datum value with the above output.

Any ideas?

2
  • So I am able to get the lib to include values in cbor now with witnesses.set_plutus_data(datumFields); however that doesn't get included in add_change_if_needed and when I try txBuilder.set_plutus_data(datumFields) I get function doesn't exist. witnesses = CardanoWasm.TransactionWitnessSet.new();
    – bakon
    May 26 at 4:00
  • You call set_plutus_data on the transaction witness set not the txBuilder. May 27 at 7:25

1 Answer 1

1

Yes, you're correct. When creating an output for a transaction, by default you only need to provide the datum hash. The consumer of that output is by default required to provide the datum that matches that hash.

If you want to provide the datum nonetheless for an output that you're creating in order to do assertions on it inside your spending validator you can do so like this:

const scripts = PlutusScripts.new();
scripts.add(PlutusScript.from_bytes(Buffer.from(<your script contract cborHex>, 'hex')));

const datumFields = CSL.PlutusList.new();
datumFields.add(CSL.PlutusData.new_integer(CSL.BigInt.from_str( ... )));
const datumConstr = CSL.ConstrPlutusData.new(
    CSL.BigNum.from_str('0'),
    datumFields
);
const datum = CSL.PlutusData.new_constr_plutus_data(datumConstr);

const transactionWitnessSet = CSL.TransactionWitnessSet.new();
transactionWitnessSet.set_plutus_scripts(scripts);
transactionWitnessSet.set_plutus_data(datum);
transactionWitnessSet.set_redeemers(...);

txBody.set_script_data_hash(hash_script_data(..., getCostModels(), datum));

{...}

export const COST_MODEL = [197209, 0, 1, 1, 396231, 621, 0, 1, 150000, 1000, 0, 1, 150000, 32, 2477736, 29175, 4, 29773, 100, 29773, 100, 29773, 100, 29773, 100, 29773, 100, 29773, 100, 100, 100, 29773, 100, 150000, 32, 150000, 32, 150000, 32, 150000, 1000, 0, 1, 150000, 32, 150000, 1000, 0, 8, 148000, 425507, 118, 0, 1, 1, 150000, 1000, 0, 8, 150000, 112536, 247, 1, 150000, 10000, 1, 136542, 1326, 1, 1000, 150000, 1000, 1, 150000, 32, 150000, 32, 150000, 32, 1, 1, 150000, 1, 150000, 4, 103599, 248, 1, 103599, 248, 1, 145276, 1366, 1, 179690, 497, 1, 150000, 32, 150000, 32, 150000, 32, 150000, 32, 150000, 32, 150000, 32, 148000, 425507, 118, 0, 1, 1, 61516, 11218, 0, 1, 150000, 32, 148000, 425507, 118, 0, 1, 1, 148000, 425507, 118, 0, 1, 1, 2477736, 29175, 4, 0, 82363, 4, 150000, 5000, 0, 1, 150000, 32, 197209, 0, 1, 1, 150000, 32, 150000, 32, 150000, 32, 150000, 32, 150000, 32, 150000, 32, 150000, 32, 3345831, 1, 1];
export const getCostModel = () => {
  const costModel = CostModel.new();
  COST_MODEL.forEach((x, i) => costModel.set(i, Int.new_i32(x)));
  const costModels = Costmdls.new();
  costModels.insert(Language.new_plutus_v1(), costModel);
  return costModels;
}

For more examples I recommend the following resources:

DApp Connector Examples

SpaceBudz Datum Creation

1
  • I am running into similar issue reported by bakon (from the reply to my question). It appears the CSL is not accounting for the datum in the output, so the fee is being miscalculated.
    – Latheesan
    May 27 at 0:21

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.