viz-transaction

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Using this library you can easily create and sign transactions for VIZ blockchain. It also allows you to multi-sign existing transactions or create them without signature at all.

NOTE: You cannot broadcast transactions to the blockchain using this library. Only serialization and signing. To send transactions to the network, use any other http/ws-library

Example transfer

Signing transfer operations with viz-transaction is very simple:

import 'package:viz_transaction/viz_transaction.dart';

void main() {
  Transaction trx = Transaction();
  trx.refBlockNum = 46179;
  trx.refBlockPrefix = 1490075988;

  Transfer transfer = Transfer(
      from: AccountName('<SENDER_LOGIN>'),
      to: AccountName('<RECEIVER_LOGIN>'),
      amount: VizAsset.fromString('1.000 VIZ'),
      memo: Memo('Hello world!'));

  trx.operations.add(transfer);
  trx.sign(['<ACTIVE_PRIVATE_KEY>']); //Sign transaction

  // And get a json string to broadcast in blockchain
  print(trx.toJsonString());
}

Example award

What about creating and signing a transaction with an award operation? Let's do it without beneficiaries.

import 'package:viz_transaction/viz_transaction.dart';

void main() {
  Transaction trx = Transaction(
      refBlockNum: 46179,
      refBlockPrefix: 1490075988);

  Award award = Award(
      initiator: AccountName('<INITIATOR_LOGIN>'),
      receiver: AccountName('<RECEIVER_LOGIN>'),
      energy: 1000, // 10.00%
      memo: Memo('Hello World'));

  trx.operations.add(award);
  trx.sign(['<REGULAR_PRIVATE_KEY>']); //Sign transaction

  print(trx.toJsonString()); // And get a json string to broadcast in blockchain
}

And now let's do the same but with two beneficiaries.

import 'package:viz_transaction/viz_transaction.dart';

void main() {
  Transaction trx = Transaction();
  trx.refBlockNum = 46179;
  trx.refBlockPrefix = 1490075988;

  Award award = Award();
  award.initiator = AccountName('<INITIATOR_LOGIN>');
  award.receiver = AccountName('<RECEIVER_LOGIN>');
  award.energy = 1000; // 10.00%
  award.memo = Memo('Hello World');
  award.beneficiaries = [
    BeneficiaryRouteType(AccountName('<BENEFICIARY_ONE>'),
        50), // Share 0.50% with BENEFICIARY_ONE
    BeneficiaryRouteType(AccountName('<BENEFICIARY_TWO>'),
        50) // Share 0.50% with BENEFICIARY_TWO
  ];

  trx.operations.add(award);
  trx.sign(['<REGULAR_PRIVATE_KEY>']); //Sign transaction

  // And get a json string to broadcast in blockchain
  print(trx.toJsonString());
}

As you may have noticed, an empty constructor was used for "award" operation, and then values were set. Just because it is possible.

Example gets ref block num and prefix

As you can see, we set refBlockNum and refBlockPrefix manually, but in any case you need to get them from the block number (height) and block identifier respectively. Fortunately, you can do this by simply calling the utils methods, as demonstrated below:

int refBlockNum = BlockchainUtils.getRefBlockNum(7097393);
int refBlockPrefix = BlockchainUtils.getRefBlockPrefix("006c4c314a0c19918caa3187abdebfeeb56724b1");

See more examples in the example folder.

Features and bugs

Please file feature requests and bugs at the issue tracker.

Libraries

viz_transaction