should input variable be initialize in class?
Hi,
I'm currently learning about class for the first time. I have 2 strategy that using the same include variable file, one for long position and the other for short position. In variable file, some of the variable contains trade direction such as SymbolsLong and SymbolsShort and it is used only for respective strategy while other is not and used for both strategy. My question is should I create an object for every strategy that used by both strategy?
i guess you have 2 obvious options - first one is to create 2 objects, each one holding either the InpSymbolsLong value or the InsymbolsShort value.
But another way is to pass the string to the object and let it react accordingly based on which string you pass - here is a simple example which hopefully illustrates both approaches.
Personally I would do option2 - just have one object and create as many methods as you need to control the entire scenario
//+------------------------------------------------------------------+ //| 458115-ClassInit.mq5 | //| Copyright 2023, MetaQuotes Ltd. | //| https://www.mql5.com | //+------------------------------------------------------------------+ #property copyright "Copyright 2023, MetaQuotes Ltd." #property link "https://www.mql5.com" #property version "1.00" //+------------------------------------------------------------------+ //| Script program start function | //+------------------------------------------------------------------+ //example of variable needed in strategy #define def_InpSymbolsLong "AUDCAD|EURUSD|GBPCHF" #define def_InpSymbolsShort "EURCHF|CADCHF|NZDUSD" input string InpSymbolsLong = def_InpSymbolsLong; input string InpSymbolsShort = def_InpSymbolsShort; input ENUM_TIMEFRAMES InpTimeframe = PERIOD_M15; input double InpVolume = 0.1; //+------------------------------------------------------------------+ //| | //+------------------------------------------------------------------+ class CStrategy_option1 { public: //should I initialize a class member to store the input variable above? ENUM_TIMEFRAMES InpTimeframe; double InpVolume; string InpSymbols; void CStrategy_option1(string inpSym) //Constructor { InpSymbols = inpSym; } int OnInitEvent() { //... return(0); } }; //+------------------------------------------------------------------+ //| | //+------------------------------------------------------------------+ class CStrategy_option2 { public: //should I initialize a class member to store the input variable above? ENUM_TIMEFRAMES InpTimeframe; double InpVolume; void selectAction(string inpSym) { if(inpSym == def_InpSymbolsLong) { //execute Long code } else if(inpSym == def_InpSymbolsShort) { //execute Short code } } int OnInitEvent() { //... return(0); } }; //+------------------------------------------------------------------+ //| | //+------------------------------------------------------------------+ void OnStart() { //--- CStrategy_option1 CStrategy_InpSymbolsLong(def_InpSymbolsLong); CStrategy_option1 CStrategy_InpSymbolsShort(def_InpSymbolsShort); CStrategy_option2 CStrategy_combo(); CStrategy_combo.selectAction(def_InpSymbolsLong); CStrategy_combo.selectAction(def_InpSymbolsShort); } //+------------------------------------------------------------------+
Thanks @R4tna C for your answer. My problem is revolve around whether I need to create an object for my variable.
I have an input variable and a global variable that will be used to accommodate multi-symbol strategy. If I use code in the OnInit below, when I call StrategyLong.OnInitEvent() function first it will set the value to a long config file but when I call StrategyShort.OnInitEvent() function it will overwrite the GV value to what is written in the short file config file.
// input variable that will be overwrite bool InpCurrencyTradingAllowed = false; TRADING_METHOD InpTradingMethod = TREND_FOLLOWING; double InpTPCoef = 200; double InpSLCoef = 100; int InpOtherCloseCoef = 0; // global variable for input variable bool CurrencyTradingAllowed[]; TRADING_METHOD TradingMethod[]; double TPCoef[]; double SLCoef[]; int OtherCloseCoef[]; int OnInit() { if(InpTradeSymbolsLong != "NONE") StrategyLong.OnInitEvent(InpTradeSymbolsLong, SymbolArrayLong, NumberOfTradeableSymbolsLong, SymbolsProcessedThisIterationLong, OpenPositionTicketLong, InpSettingsFileLong); if(InpTradeSymbolsShort != "NONE") StrategyShort.OnInitEvent(InpTradeSymbolsShort, SymbolArrayShort, NumberOfTradeableSymbolsShort, SymbolsProcessedThisIterationShort, OpenPositionTicketShort, InpSettingsFileShort); return (INIT_SUCCEEDED); }
To fix this problem, I want to create a class member to save each value from a long strategy and short strategy
CStrategy {
private:
bool m_CurrencyTradingAllowed[];
TRADING_METHOD m_TradingMethod[];
double m_TPCoef[];
double m_SLCoef[];
int m_OtherCloseCoef[];
void InitConfigFile(string& SymbolArray[], int SymbolLoop, int numberOfTradeableSymbols, string FileName) {
// assign GV to input variable
CurrencyTradingAllowed[SymbolLoop] = InpCurrencyTradingAllowed;
TradingMethod[SymbolLoop] = InpTradingMethod;
TPCoef[SymbolLoop] = InpTPCoef;
SLCoef[SymbolLoop] = InpSLCoef;
OtherCloseCoef[SymbolLoop] = InpOtherCloseCoef;
// overwrite GV to value in config file
InitLoadFile();
m_CurrencyTradingAllowed[SymbolLoop] = CurrencyTradingAllowed[SymbolLoop];
m_TradingMethod[SymbolLoop] = TradingMethod[SymbolLoop];
m_TPCoef[SymbolLoop] = TPCoef[SymbolLoop];
m_SLCoef[SymbolLoop] = SLCoef[SymbolLoop];
m_OtherCloseCoef[SymbolLoop] = OtherCloseCoefp[SymbolLoop];
}
// function to look into config file and overwrite the variable
InitLoadFile(string& SymbolArray[], int SymbolLoop, int numberOfTradeableSymbols, string FileName) {
...
CurrencyTradingAllowed[SymbolLoop] = currencyTradingAllowed; // currencyTradingAllowed value from strategy config file
TradingMethod[SymbolLoop] = tradingMethod; // tradingMethod value from strategy config file
TPCoef[SymbolLoop] = tpCoef; // tpCoef value from strategy config file
SLCoef[SymbolLoop] = slCoef; // slCoef value from strategy config file
OtherCloseCoef[SymbolLoop] = otherCloseCoef; // otherCloseCoef value from strategy config file
...
}
}; I tried using this code to set the class member but all GV for long strategy still overwritten by short strategy.
I tried using this code to set the class member but all GV for long strategy still overwritten by short strategy.
Sounds like you have gone for the 2 object approach which is fine, but I only glanced at your code and not sure if I understand your explanation fully.
But it seems you have a conflict with single global variable being shared and overwritten - so why not store that data as an attribute/property of each object, so it is coupled with the object and thus will not conflict with the other objects usage?
That could be better than using a global variable - worth checking out
But it seems you have a conflict with single global variable being shared and overwritten - so why not store that data as an attribute/property of each object, so it is coupled with the object and thus will not conflict with the other objects usage?
Hi @R4tna C! Yes this is what I'm currently facing on!. Could you elaborate more about this part?
Yes this is what I'm currently facing on!. Could you elaborate more about this part?
Create a variable inside the object - and push the value into the object.
e.g. if you need to store a unique filepath for each object:
CStrategy {
private:
bool m_CurrencyTradingAllowed[];
TRADING_METHOD m_TradingMethod[];
double m_TPCoef[];
double m_SLCoef[];
int m_OtherCloseCoef[];
string m_filepath; StrategyLong.m_filepath will contain the long file path
StrategyShort.m_filepath will contain the short file path
No chance of confusion or overwrite - remove the global variable and refer to this property of each object as needed
Create a variable inside the object - and push the value into the object.
e.g. if you need to store a unique filepath for each object:
StrategyLong.m_filepath will contain the long file path
StrategyShort.m_filepath will contain the short file path
No chance of confusion or overwrite - remove the global variable and refer to this property of each object as needed
This is my input variable for this strategy,
input string LongStrategyDesc = "--------- Long Strategy ----------"; // - input string InpTradeSymbolsLong = "CURRENT"; // Symbol(s) - CURRENT | ALLCUR | CURRENCY NAME | NONE input TRADE_DIRECTION InpTradeDirectionLong = LONG_ONLY; // Trade direction input string InpSettingsFileLong = "D:\\Configuration EA files\\10 trend following\\StdDev_X_RVI Long Config.ini"; // Name input file, blank = not used input string ShortStrategyDesc = "--------- Short Strategy ----------"; // - input string InpTradeSymbolsShort = "CURRENT"; // Symbol(s) input TRADE_DIRECTION InpTradeDirectionShort = SHORT_ONLY; // Trade direction input string InpSettingsFileShort = "D:\\Configuration EA files\\10 trend following\\StdDev_X_RVI Short Config.ini"; // Name input file, blank = not used input ENUM_TIMEFRAMES InpTradeTimeframe = PERIOD_M15; // Trading timeframe input ENUM_BAR_PROCESSING_METHOD InpBarProcessingMethod = ONLY_PROCESS_TICKS_FROM_NEW_TRADE_TF_BAR; // EA bar processing method input bool InpCurrencyTradingAllowed = false; // Is trade allowed for specified currency input TRADING_METHOD InpTradingMethod = TREND_FOLLOWING; // Trading method input group "Trade Setting" input string GroupDesc2 = "===== TRADE SETTING ====="; input string SectionDesc2 = "***** Volume or Lot setting *****"; // - input VOLUME_MODE InpVolumeMode = VOLUME_MODE_FIXED; // Lot mode input double InpVolume = 0.01; // Lots / money / equity divisor / percent input string SectionDesc3 = "***** TP/SL/Trail Stop setting *****"; // - input STOPLOSS_METHOD InpStoplossMethod = NONE1; // Stoploss method input double InpSLCoef = 0; // Point/dollar/ATR mltp/bar(s) input TAKE_PROFIT_METHOD InpTakeProfitMethod = NONE2; // Take profit method input double InpTPCoef = 0; // Point/dollar/multiplier input OTHER_CLOSE_METHOD InpOtherCloseMethod = NONE3; // Other close method input int InpOtherCloseCoef = 0; // *Close X next bar(s) input string SectionDesc4 = "***** other general setting *****"; // - input ulong InpSlippage = 10; // Slippage in points input int InpMaxSpread = 20; // Maximum spread allowed input ulong InpMagicNumber = 1; // Magic number
as you can see, some of the input variable has 2 input based on the strategy itself. This variable that will be change to whatever written in the config file.
This is my input variable for this strategy,
as you can see, some of the input variable has 2 input based on the strategy itself. This variable that will be change to whatever written in the config file.
Not sure I follow you - but even if the variable needs to be changed to whatever the config file, you could hold that info "inside" the object and rely on that to correct rather than risking global variable conflicts
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Hi,
I'm currently learning about class for the first time. I have 2 strategy that using the same include variable file, one for long position and the other for short position. In variable file, some of the variable contains trade direction such as SymbolsLong and SymbolsShort and it is used only for respective strategy while other is not and used for both strategy. My question is should I create an object for every strategy that used by both strategy?