is a wasy way to wait complete?

[小宝软件]

if i want do three step like
1.approve
2.sendTrans
3.transfer

because library is run in task so how can i wait affrove ok then sendtrans then transfer?

Delphi do not have something like await/async

[Stefan]

Everything Delphereum does is async. If you want to approve a token and then wait for the transaction to get mined before you transfer (or do anything else), here is how:

const erc20 = TERC20.Create(client, token);
erc20.ApproveEx(owner, spender, web3.Infinite, procedure(rcpt: ITxReceipt; err: IError)
begin
  if Assigned(err) then
  begin
    // handle error
    EXIT;
  end;
  erc20.TransferEx(owner, blah blah blah, procedure(rcpt: ITxReceipt; err: IError)
  begin
    if Assigned(err) then
    begin
      // handle error
      EXIT;
    end;
    // continue with your next step
  end);
end);

As a general rule, the non-Ex functions -- such as Approve() and Transfer() -- return immediately with a hash of the transaction, while the Ex functions -- such as ApproveEx() and TransferEx() -- wait for the transaction to get mined and then return a receipt of the transaction.

[小宝软件]

Everything Delphereum does is async. If you want to approve a token and then wait for the transaction to get mined before you transfer (or do anything else), here is how:

const erc20 = TERC20.Create(client, token);
erc20.ApproveEx(owner, spender, web3.Infinite, procedure(rcpt: ITxReceipt; err: IError)
begin
  if Assigned(err) then
  begin
    // handle error
    EXIT;
  end;
  erc20.TransferEx(owner, blah blah blah, procedure(rcpt: ITxReceipt; err: IError)
  begin
    if Assigned(err) then
    begin
      // handle error
      EXIT;
    end;
    // continue with your next step
  end);
end);

As a general rule, the non-Ex functions -- such as Approve() and Transfer() -- return immediately with a hash of the transaction, while the Ex functions -- such as ApproveEx() and TransferEx() -- wait for the transaction to get mined and then return a receipt of the transaction.

SendTrans cant do like this. have other way?thanks

[小宝软件]

Everything Delphereum does is async. If you want to approve a token and then wait for the transaction to get mined before you transfer (or do anything else), here is how:

const erc20 = TERC20.Create(client, token);
erc20.ApproveEx(owner, spender, web3.Infinite, procedure(rcpt: ITxReceipt; err: IError)
begin
  if Assigned(err) then
  begin
    // handle error
    EXIT;
  end;
  erc20.TransferEx(owner, blah blah blah, procedure(rcpt: ITxReceipt; err: IError)
  begin
    if Assigned(err) then
    begin
      // handle error
      EXIT;
    end;
    // continue with your next step
  end);
end);

As a general rule, the non-Ex functions -- such as Approve() and Transfer() -- return immediately with a hash of the transaction, while the Ex functions -- such as ApproveEx() and TransferEx() -- wait for the transaction to get mined and then return a receipt of the transaction.

if i want do many step. this way will be very deep.

xxxxx(x,
procedure
begin
yyyyy(y,
procedure
begin
zzzz(z, procedure
begin
end
)
end
);
end;
)

like this more and more deep....