signTransaction method

AptosSignedTransaction signTransaction({ required AptosAccount<AptosAccountPublicKey, AptosAccountAuthenticator, AptosSignature> account, required AptosRawTransaction transaction, AptosAccount<AptosAccountPublicKey, AptosAccountAuthenticator, AptosSignature>? feePayerAccount, List<AptosAccount<AptosAccountPublicKey, AptosAccountAuthenticator, AptosSignature>>? secondarySignerAccounts, })

Signs an Aptos raw transaction with the provided account.

• account: The primary account responsible for signing the transaction.
• transaction: The raw transaction to be signed.
• feePayerAccount (optional): An additional account that covers the transaction fee, if applicable.
• secondarySignerAccounts (optional): A list of secondary accounts for multi-agent transactions.

Returns an AptosSignedTransaction containing the raw transaction and its corresponding authenticator.

Implementation

AptosSignedTransaction signTransaction({
  required AptosAccount account,
  required AptosRawTransaction transaction,
  AptosAccount? feePayerAccount,
  List<AptosAccount>? secondarySignerAccounts,
}) {
  final digest = transaction.signingSerialize(
    feePayerAddress: feePayerAccount?.toAddress(),
    secondarySignerAddresses:
        secondarySignerAccounts?.map((e) => e.toAddress()).toList(),
  );

  // Sign the transaction digest with the primary account
  final sender = account.signWithAuth(digest);

  // Sign with fee payer account if provided
  AptosAccountAuthenticator? feePayerAuthenticator = feePayerAccount
      ?.signWithAuth(digest);

  // Sign with secondary signer accounts if provided
  List<AptosAccountAuthenticator>? secondarySignerAuthenticator =
      secondarySignerAccounts?.map((e) => e.signWithAuth(digest)).toList();

  // Build the transaction authenticator based on the provided signers
  final txAuthenticated = _toTransactionAuthenticated(
    sender: sender,
    feePayerAddress: feePayerAccount?.toAddress(),
    feePayerAuthenticator: feePayerAuthenticator,
    secondarySignerAddressess:
        secondarySignerAccounts?.map((e) => e.toAddress()).toList(),
    secondarySignerAuthenticated: secondarySignerAuthenticator,
  );

  return AptosSignedTransaction(
    rawTransaction: transaction,
    authenticator: txAuthenticated,
  );
}