MQL5 CTrade Class Guide: Buy, PositionClose & PositionModify Signatures

//+------------------------------------------------------------------+
//|                                            CTradeClassGuideEA.mq5 |
//|                             Copyright 2026, Pineify Guides Series |
//|                                              https://pineify.app |
//+------------------------------------------------------------------+
#property copyright "Pineify Guides Series"
#property link      "https://pineify.app/mql5/ctrade-class-guide"
#property version   "1.00"
#property strict

// Include standard trade library
#include <Trade\Trade.mqh>

//--- Input parameters
input group "--- Order Settings ---"
input bool AllowDemoOrder=false; // Explicit demo-only, one-attempt method example
input double InpLotSize         = 0.10;   // Lot volume
input int    InpStopLossPoints  = 250;    // Stop Loss in points
input int    InpTakeProfitPoints= 500;    // Take Profit in points
input ulong  InpSlippagePoints  = 20;     // Max slippage in points
input ulong  InpMagicNumber     = 101001; // EA Magic Number

//--- Global trade instance
CTrade trade;

//+------------------------------------------------------------------+
//| Expert initialization function                                   |
//+------------------------------------------------------------------+
int OnInit()
  {
   // Configure CTrade instance
   trade.SetExpertMagicNumber(InpMagicNumber);
   trade.SetDeviationInPoints(InpSlippagePoints);
   trade.SetTypeFillingBySymbol(_Symbol);
   trade.SetAsyncMode(false); // Synchronous request; still inspect server result

   Print("CTrade initialized successfully. Magic: ", InpMagicNumber);
   return(INIT_SUCCEEDED);
  }

//+------------------------------------------------------------------+
//| Helper: Open a long position using CTrade::Buy                  |
//+------------------------------------------------------------------+
bool OpenBuyOrder(double lots, int slPoints, int tpPoints, const string comment="Pineify Buy")
  {
   double ask = SymbolInfoDouble(_Symbol, SYMBOL_ASK);
   double point = SymbolInfoDouble(_Symbol, SYMBOL_POINT);
   int digits = (int)SymbolInfoInteger(_Symbol, SYMBOL_DIGITS);

   double sl = (slPoints > 0) ? NormalizeDouble(ask - slPoints * point, digits) : 0.0;
   double tp = (tpPoints > 0) ? NormalizeDouble(ask + tpPoints * point, digits) : 0.0;

   // Call CTrade::Buy signature: (volume, symbol, price, sl, tp, comment)
   if(trade.Buy(lots, _Symbol, ask, sl, tp, comment))
     {
      uint retcode = trade.ResultRetcode();
      if(retcode == TRADE_RETCODE_DONE)
        {
         PrintFormat("Buy request completed. Order Ticket: %I64u, Deal: %I64u, Price: %.*f",
                     trade.ResultOrder(), trade.ResultDeal(), digits, ask);
         return true;
        }
      PrintFormat("Buy returned true but retcode is %u (%s)",
                  retcode, trade.ResultRetcodeDescription());
      return false;
     }

   PrintFormat("CTrade::Buy failed! Retcode: %u (%s)",
               trade.ResultRetcode(), trade.ResultRetcodeDescription());
   return false;
  }

//+------------------------------------------------------------------+
//| Helper: Modify position stop loss and take profit                |
//+------------------------------------------------------------------+
bool ModifyPositionSLTP(ulong ticket, double newSL, double newTP)
  {
   if(!PositionSelectByTicket(ticket) || PositionGetString(POSITION_SYMBOL)!=_Symbol ||
      PositionGetInteger(POSITION_MAGIC)!=(long)InpMagicNumber) return false;
   if(!trade.PositionModify(ticket, newSL, newTP) || trade.ResultRetcode()!=TRADE_RETCODE_DONE)
     {
      PrintFormat("PositionModify failed for ticket %I64u: %u (%s)",
                  ticket, trade.ResultRetcode(), trade.ResultRetcodeDescription());
      return false;
     }
   PrintFormat("Position %I64u modified successfully to SL: %f, TP: %f",
               ticket, newSL, newTP);
   return true;
  }

//+------------------------------------------------------------------+
//| Helper: Close position safely                                    |
//+------------------------------------------------------------------+
bool CloseSpecificPosition(ulong ticket)
  {
   if(!PositionSelectByTicket(ticket) || PositionGetString(POSITION_SYMBOL)!=_Symbol ||
      PositionGetInteger(POSITION_MAGIC)!=(long)InpMagicNumber) return false;
   if(!trade.PositionClose(ticket) || trade.ResultRetcode()!=TRADE_RETCODE_DONE)
     {
      PrintFormat("PositionClose failed for ticket %I64u: %u (%s)",
                  ticket, trade.ResultRetcode(), trade.ResultRetcodeDescription());
      return false;
     }
   PrintFormat("Position %I64u closed successfully", ticket);
   return true;
  }

//+------------------------------------------------------------------+
//| Expert tick function                                             |
//+------------------------------------------------------------------+
void OnTick()
  {
   static bool attempted=false;
   if(!AllowDemoOrder || attempted || AccountInfoInteger(ACCOUNT_TRADE_MODE)!=ACCOUNT_TRADE_MODE_DEMO) return;
   if(PositionsTotal() == 0)
     {
      attempted=true; // Do not retry an ambiguous or rejected request automatically.
      OpenBuyOrder(InpLotSize, InpStopLossPoints, InpTakeProfitPoints, "Pineify CTrade Demo");
     }
  }