7
votes
Accepted
How can I enforce a datum type to be correct?
Hopefully I'm following your question...
I'm not aware of any type checks performed at validation, but I'm also not aware of any situation that a validator/script would need to spend resources ...
- 3,247
5
votes
Accepted
Plutus datum and redeemer on cardano-cli
Have a look at the following source Cardano-Api Haddock. Here you will find all about the conversion between Haskell data types and the Json format the cardano-cli uses.
I noticed that you used the ...
- 1,872
5
votes
Accepted
How do I read the datum of an output?
If you are running a DbSync node you can retrieve the datum and redeemer:
redeemer
A table containing redeemers. A redeemer is provided for all items that are validated by a script.
Primary Id: id
...
- 755
4
votes
Accepted
Plutus pattern/technique for finding original datum preimage of TxOutDatumHash?
Datums are stored on-chain. There is part of PAB called chain-index - it follows the node, pulls Datums and stores them in local database (see here section Plutus Application Backend).
So for your ...
4
votes
Accepted
Is function "isPayToScriptOut" unsafe?
Your deductions are partially correct. isPayToScriptOut looks at the credentials of an address (1) and return true if it is a script address, false if it is a public key credential. It thus does not ...
- 1,872
3
votes
Accepted
What is the mkValidator Script
A validator script locks transaction outputs. This function is where you define conditions to unlock them. https://plutus.readthedocs.io/en/latest/tutorials/basic-validators.html
- 1,560
3
votes
What is the mkValidator Script
On Cardano logic can be enforced on how UTxO's are spend by attaching a "script" to the transaction + some inputs that will be used to run the script (the datum, redeemer and context). ...
- 1,872
3
votes
Accepted
Is it possible to send funds to a scriptAddress using a lightweight wallet?
This answer will surely age fast.
At the time of writing both Nami V3.2.0 and Yoroi Nightly 4.11.501 allow you send to script address, but neither advertise any options of setting datums. Nami allows ...
- 403
3
votes
Plutus datum and redeemer on cardano-cli
{
"constructor": 0,
"fields": {int: 42}
}
This isn't valid because fields must be an array. The index of the constructor and fields will match the order of types defined for the ...
- 1,560
3
votes
Accepted
How to create Datum with ownPaymentPubKeyHash?
You are using the operator <- to bind the result to pkh. That means that pkh is of type PaymentPubKeyHash. If the equality fails then because of another reason. If pkh wasn’t of the right type you ...
- 1,521
3
votes
Is Redeemer similar to <ScriptSig> in bitcoin context?
One way to think of it is that:
The Datum is a piece of data that's attached to the UTXO by the producer,
The Redeemer is a piece of data that's provided by the consumer,
When the UTXO is consumed, ...
- 224
3
votes
Accepted
How to pass TxOutDatumNone when building a script transaction with cardano-cli
I'm afraid that presenting a "none" datum is not possible. This also means that this UtxO is lost (anybody, correct me if I'm wrong)
I don't know the very reason why it is possible to send a ...
3
votes
How can I secure a Datum value in a smart contract?
There are multiple ways to do that.
Option 1:
If you have "script-wide" constants, like your mentioned example of an auction house fee, I suggest parameterizing your contract like it is done ...
- 1,162
3
votes
Accepted
A Script With Multiple Different Datum Types
let's say we have a Maybe Integer type, then the value must be assigned as either Just 3 or Nothing.
Directly assigning it as 3 won't work.
So your QuadraDatum should be created as
let dat = ...
- 196
3
votes
Get Value of Datum from a UTXO
The upshot is that you might not find a datum, but instead get a hash of the datum (it depends).
When submitting a transaction, the full "unhashed" datum is not automatically attached to the ...
- 1,872
2
votes
Accepted
Ensuring NFT collection uniqueness using counter as asset name?
This should work. I don't see any obvious ways of tampering with it. As long as you are checking against the token name, not the currency symbol, these tokens would be non-fungible and unique.
To ...
- 3,247
2
votes
How can I enforce a datum type to be correct?
You should be extra careful with data that is being provided to smart contracts by the user. You might prevent user errors by using data from the Context that is already provided to you inside the ...
- 321
2
votes
How to specify the new output datum value (not hash) using the CLI
I already found the answer and will leave it here in case anyone ran into the same problem.
You need to update the node-cli version to the lastest version (currently) 1.31.0 and then you have the ...
- 755
2
votes
What is where executed and when?
One detail to add here:
In short:
if another Tx generator wants to use the same script, but one or more blocks later, it will need the datum (previous state of the script), which must be exposed by ...
- 101
2
votes
Accepted
What is the role of datum in spending a transaction
I thought datum was used to keep track of the state of the script.
It can be and often is. This is how its used in a StateMachine, for example.
The cardano chain is 'lean': only the necessary ...
- 403
2
votes
PlutusData construction using @emurgo cardano-serialization-lib-browser
Maybe this will help,
typhonjs supports creating plutusDataCbor using utility method
const plutusDataBuffer = typhonjs.utils.createPlutusDataCbor({
constructor: 0,
fields: [12, 12],
});
const ...
- 206
2
votes
Accepted
Get Value of Datum from a UTXO
The ChainIndexTxOut type has a data field called _ciTxOutValue :: Value and another that is _ciTxOutDatum :: Either DatumHash Datum I'll show you how to get the value. Getting the datum is the same ...
- 58
2
votes
Loading specific Datum JSON with Map structure into Plutus type
You could define a union type for values, something like
data Val = B BuiltinByteString
| M (AssocMap BuiltinByteString Val)
type OrcFax = AssocMap BuiltinByteString Val
then you can deserialise ...
- 224
1
vote
Accepted
Different Data tyoes for datum
You can combine the two like this
data DatumAction = VotingDatum | StartDatum
Then you can specify in you validator which case is used like this
mkValidator :: DatumAction -> redeemer -> ...
- 1,872
1
vote
PlutusData construction using @emurgo cardano-serialization-lib-browser
Mehul was correct. @strictahq/typhonjs does work correctly and produces the same result as
cardano-cli transaction hash-script-data --script-data-file test.json
Where test.json contents are:
{ "...
- 123
1
vote
Using custom datum for `mustPayToOtherScript` in off-chain code
As far as I know your datum types are required to conform the Data type.
Try:
PlutusTx.makeIsDataIndexed ''RandomDatum [ ('RandomDatum, 0) ]
{...}
let randomDatum = RandomDatum { ...params... }
...
- 1,162
1
vote
Accepted
Missing datums in db-sync
As datums values are included in the witness set of the corresponding
transactions
This is not true all of the time. When you create a new script UTxO by sending some amount of tokens to it, you don'...
- 988
1
vote
What is where executed and when?
The blockchain does not only store hashes. It also stores the datum and the script of spent UTxOs. It would otherwise not be possible to validate the transaction in retrospect. So while you don't need ...
- 1,521
1
vote
How does Constraints.mustHashDatum work?
This is my beginner takeaway about Constraints.mustHashDatum after reading about TxContraints and TxConstraint and mustHashDatum at the Ledger.Constraints documentation link below. I will also be ...
- 11
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