When are we use POSITION_MAGIC, ORDER_MAGIC, DEAL_MAGIC?

OrderSend() sequence.

1. OrderSend() call initiates an Order.
2. The Order then initiates a Deal and then Order is closed.
3 On acceptance of Deal by Broker's server, a Symbol Position is opened and then Deal is closed.

ORDER_MAGIC and DEAL_MAGIC would be used in HistorySelect as part of closed Order or Deal selection process.

HistorySelect() Example:

double LastDealPrice() // Last Deal open price for chart symbol

{

uint total=0;

long ticket;

string symbol;

long magic;

HistorySelect(0,TimeCurrent());

total=HistoryDealsTotal();

for(uint i=0;i <total; i++)

{

ticket=HistoryDealGetTicket(i);

symbol=HistoryDealGetString(ticket,DEAL_SYMBOL);

magic=HistoryDealGetInteger(ticket,DEAL_MAGIC);

if( symbol==Symbol() && magic==MagicNumber)

{

Lprice=HistoryDealGetDouble(ticket,DEAL_PRICE);

}

}

return(Lprice);

}

POSITION_MAGIC is used in current open Position selection process.

PositionSelect() example:

int CurPosLots() // total lots in current symbol position

{

int total=PositionsTotal();

double lots=0;

for (int cnt=0; cnt<total; cnt++)

{

if(PositionSelect(Sysbol()) )

{

if(PositionGetInteger(POSITION_MAGIC)==MagicNumber)

{

lots=PositionGetDouble(POSITION_VOLUME);

}

}

}

return(lots);

}