Add a utility to conveniently create UTxO from the return of CIP30 api's getUtxos.

[mrvfino]

This PR is to:

• make it easier to convert the utxos coming from the frontend via CIP30 api

I got this idea while looking for a way to save on blockfrost api calls, & a way to get utxos from the account itself to use in the tx builder as an alternative to add_input_address when an unused address i provided.

[cffls]

Thanks for raising this PR! Regarding the cbor of UTxO, is there a spec for it documented somewhere? I am wondering if it is specific to a frontend wallet.

[mrvfino]

Hi @cffls!

Is this it?https://cips.cardano.org/cips/cip30/#apigetutxosamountcborvalueundefinedpaginatepaginateundefinedpromisetransactionunspentoutputnull

Based on my understanding, all frontend wallets that are CIP30 compatible should follow the same return.

EDIT: Perhaps the function could have better naming, yes? like convert_from_CIP30_cbor

[cffls]

Thanks @markrufino ! I think this could be simplified by making UTxO as a child class of ArrayCBORSerializable, something like this:

@dataclass(repr=False)
class UTxO(ArrayCBORSerializable):
    ...
    # rest of the code will be the same

and you will be able to deserialize a UTxO cbor string like the following:

utxo = UTxO.from_cbor(my_cbor_string)

If you can provide me with a CBOR string example, I am happy to test it.

[mrvfino]

Interesting, let me try that as well. Thanks @cffls!

Also, here are some sample cbor strings.

[
    "828258207e4858f94be25d27e5d12ec779c5ace21f97f5051785ce90c3031685bb86eff40082583901316762a13a4587945d254cf8d35621d98c60ce739ad5d2d88e2955070c552e116f1f0bb17ea6bdcaa3d6c26abc77012f4286554173451d261a25ab8e00",
    "82825820b07182d18ee49f02908bf7c92b2fc25027c2d43f6c83a0cf3bd082f5a10f5d0a0082583901316762a13a4587945d254cf8d35621d98c60ce739ad5d2d88e2955070c552e116f1f0bb17ea6bdcaa3d6c26abc77012f4286554173451d261a054e0840"
]

Stake key of the owning account just in case you need it: stake1uyx92ts3du0shvt7567u4g7kcf4tcacp9apgv42pwdz36fs80m0r0

[cffls]

Thanks! Looks like it works:

>>> UTxO.from_cbor("828258207e4858f94be25d27e5d12ec779c5ace21f97f5051785ce90c3031685bb86eff40082583901316762a13a4587945d254cf8d35621d98c60ce739ad5d2d88e2955070c552e116f1f0bb17ea6bdcaa3d6c26abc77012f4286554173451d261a25ab8e00")
{'input': {
  'index': 0,
  'transaction_id': TransactionId(hex='7e4858f94be25d27e5d12ec779c5ace21f97f5051785ce90c3031685bb86eff4'),
},
 'output': {
  'address': addr1qyckwc4p8fzc09zay4x0356ky8vcccxwwwddt5kc3c542pcv25hpzmclpwchaf4ae23adsn2h3mszt6zse25zu69r5nqhnmggr,
  'amount': {'coin': 632000000, 'multi_asset': {}},
  'datum': None,
  'datum_hash': None,
  'script': None,
}}

>>> UTxO.from_cbor("82825820b07182d18ee49f02908bf7c92b2fc25027c2d43f6c83a0cf3bd082f5a10f5d0a0082583901316762a13a4587945d254cf8d35621d98c60ce739ad5d2d88e2955070c552e116f1f0bb17ea6bdcaa3d6c26abc77012f4286554173451d261a054e0840")
{'input': {
  'index': 0,
  'transaction_id': TransactionId(hex='b07182d18ee49f02908bf7c92b2fc25027c2d43f6c83a0cf3bd082f5a10f5d0a'),
},
 'output': {
  'address': addr1qyckwc4p8fzc09zay4x0356ky8vcccxwwwddt5kc3c542pcv25hpzmclpwchaf4ae23adsn2h3mszt6zse25zu69r5nqhnmggr,
  'amount': {'coin': 89000000, 'multi_asset': {}},
  'datum': None,
  'datum_hash': None,
  'script': None,
}}

[mrvfino]

@cffls that's great! I think we can close this then.

[cffls]

We still this change below to make it work:

@dataclass(repr=False)
class UTxO(ArrayCBORSerializable):
    ...
    # rest of the code will be the same

If you want to contribute to the project, you can modify this PR to use this change. :D Otherwise, I will add this change in the next release.

[mrvfino]

@cffls I will do add it in then! Haha would really love to be a contributor for a project I enjoy using.

EDIT: pushed the minor change! :D

[cffls]

Thank you for contributing!