Expert Advisor Programming by Andrew R. Young

Working with Functions
Order Closing Function
Lastly, let's create a function for closing a single order. We'll use the order closing block from the code
on page 58. In the next chapter, we'll examine ways of closing multiple orders of the same type,
which is a simpler method of closing orders. But in case you need to close just one order, this
function will do the trick:
bool CloseBuyOrder(string argSymbol, int argCloseTicket, double argSlippage)
{
OrderSelect(argCloseTicket,SELECT_BY_TICKET);
if(OrderCloseTime() == 0)
{
double CloseLots = OrderLots();
while(IsTradeContextBusy()) Sleep(10);
double ClosePrice = MarketInfo(argSymbol,MODE_ASK);
bool Closed = OrderClose(argCloseTicket,CloseLots,ClosePrice,argSlippage,Red);
if(Closed == false)
{
int ErrorCode = GetLastError();
string ErrDesc = ErrorDescription(ErrorCode);
string ErrAlert = StringConcatenate("Close Buy Order - Error: ",ErrorCode,
": ",ErrDesc);
Alert(ErrAlert);
}
}
string ErrLog = StringConcatenate("Ticket: ",argCloseTicket," Ask: ",
MarketInfo(argSymbol,MODE_ASK));
Print(ErrLog);
}
return(Closed);
For the ClosePrice variable, we use MarketInfo() to retrieve the current Ask price for the currency
indicated by argSymbol. We use the function arguments argCloseTicket and argSlippage for the
closing order ticket and the slippage, respectively. If the order was not closed successfully, we run
the error handling block, which prints the ticket number and current Ask price to the log.
The code to close a sell order will be identical, except that you'd use the Bid price for the
ClosePrice variable. You can view the sell market close function in Appendix D.
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