/// <summary>
/// approve the "to" account to transfer "approvedValue" tokens from the originator acount.
/// </summary>
/// <param name="originator"></param>
/// <param name="to"></param>
/// <param name="amount"></param>
/// <param name="caller"></param>
/// <param name="entry"></param>
/// <returns></returns>
public static bool Approve(byte[] originator, byte[] to, BigInteger amount, byte[] caller, byte[] entry)
{
if (caller != entry && !Helpers.IsContractWhitelistedTransferFrom(caller))
{
originator = caller;
}
if (amount < 0 || originator == to)
{
// don't accept a meaningless value
Runtime.Log("Approve() invalid transfer amount or from==to");
return(false);
}
if (originator.Length != 20 || to.Length != 20)
{
Runtime.Log("Approve() (to|originator).Length != 20");
return(false);
}
if (!Runtime.CheckWitness(originator))
{
// ensure transaction is signed properly by the owner of the tokens
Runtime.Log("Approve() CheckWitness failed");
return(false);
}
BigInteger fromBalance = BalanceOf(originator); // retrieve balance of originating account
if (fromBalance < amount)
{
Runtime.Log("Approve() fromBalance < approveValue");
// don't approve if funds not available
return(false);
}
Helpers.SetAllowanceAmount(originator.Concat(to), amount);
//OnApprove(originator, to, amount)
return(true);
}
/// <summary>
/// transfer an amount from the "from" account to the "to" acount if the originator has been approved to transfer the requested amount.
/// </summary>
/// <param name="originator"></param>
/// <param name="from"></param>
/// <param name="to"></param>
/// <param name="amount"></param>
/// <param name="caller"></param>
/// <param name="entry"></param>
/// <returns></returns>
public static bool TransferFrom(byte[] originator, byte[] from, byte[] to, BigInteger amount, byte[] caller, byte[] entry)
{
if (Helpers.GetBlockTimestamp() < ICOTemplate.PublicSaleEndTime())
{
Runtime.Log("TransferFrom() not available before ICOTemplate.PublicSaleEndTime()");
return(false);
}
if (caller != entry && !Helpers.IsContractWhitelistedTransferFrom(caller))
{
originator = caller;
}
if (originator.Length != 20 || from.Length != 20 || to.Length != 20)
{
Runtime.Log("TransferFrom() (originator|from|to).Length != 20");
return(false);
}
if (amount < 0)
{
Runtime.Log("TransferFrom() invalid transfer amount must be >= 0");
throw new Exception();
}
BigInteger approvedTransferAmount = Allowance(from, to); // how many tokens is this address authorised to transfer
BigInteger fromBalance = BalanceOf(from); // retrieve balance of authorised account
if (approvedTransferAmount < amount || fromBalance < amount)
{
// don't transfer if funds not available
Runtime.Notify("TransferFrom() (authorisedAmount|fromBalance) < transferValue", approvedTransferAmount, fromBalance, amount);
return(false);
}
if (amount == 0 || from == to)
{
// don't accept a meaningless value
Runtime.Log("TransferFrom() empty transfer amount or from==to");
transfer(from, to, amount);
return(true); // as per nep5 standard - return true when amount is 0 or from == to
}
if (!Runtime.CheckWitness(originator))
{
// ensure transaction is signed properly by the request originator
Runtime.Log("TransferFrom() CheckWitness failed");
return(false);
}
BigInteger recipientBalance = BalanceOf(to);
BigInteger recipientAmountSubjectToVesting = TokenSale.SubjectToVestingPeriod(to);
BigInteger senderAmountSubjectToVesting = TokenSale.SubjectToVestingPeriod(from);
BigInteger newBalance = fromBalance - amount;
Helpers.SetBalanceOf(from, newBalance + senderAmountSubjectToVesting); // remove balance from originating account
Helpers.SetBalanceOf(to, recipientBalance + recipientAmountSubjectToVesting + amount); // set new balance for destination account
Helpers.SetAllowanceAmount(from.Concat(originator), approvedTransferAmount - amount); // deduct transferred amount from allowance
transfer(from, to, amount);
return(true);
}
/// <summary>
/// NEP5: Transfer tokens from one account to another
/// </summary>
/// <param name="from">sender address</param>
/// <param name="to">recipient address</param>
/// <param name="amount">number of tokens to transfer</param>
/// <param name="caller"></param>
/// <param name="entry"></param>
/// <returns></returns>
public static bool Transfer(byte[] from, byte[] to, BigInteger amount, byte[] caller, byte[] entry)
{
if (Helpers.GetBlockTimestamp() < ICOTemplate.PublicSaleEndTime())
{
Runtime.Log("Transfer() not available before ICOTemplate.PublicSaleEndTime()");
return(false);
}
if (caller != entry && !Helpers.IsContractWhitelistedTransferFrom(caller))
{
from = caller;
}
if (from.Length != 20 || to.Length != 20)
{
Runtime.Log("Transfer() (from|to).Length != 20");
return(false);
}
if (amount < 0)
{
Runtime.Log("Transfer() invalid transfer amount must be >= 0");
throw new Exception();
}
BigInteger fromBalance = BalanceOf(from); // retrieve balance of originating account
if (fromBalance < amount)
{
Runtime.Log("Transfer() fromBalance < transferValue");
// don't transfer if funds not available
return(false);
}
if (amount == 0 || from == to)
{
// don't accept a meaningless value
Runtime.Log("Transfer() empty transfer amount or from==to");
transfer(from, to, amount);
return(true); // as per nep5 standard - return true when amount is 0 or from == to
}
if (!Runtime.CheckWitness(from))
{
// ensure transaction is signed properly by the owner of the tokens
Runtime.Log("Transfer() CheckWitness failed");
return(false);
}
BigInteger recipientBalance = BalanceOf(to);
BigInteger recipientAmountSubjectToVesting = TokenSale.SubjectToVestingPeriod(to);
BigInteger senderAmountSubjectToVesting = TokenSale.SubjectToVestingPeriod(from);
BigInteger newBalance = fromBalance - amount;
Helpers.SetBalanceOf(from, newBalance + senderAmountSubjectToVesting); // remove balance from originating account
Helpers.SetBalanceOf(to, recipientBalance + recipientAmountSubjectToVesting + amount); // set new balance for destination account
transfer(from, to, amount);
return(true);
}
