How can I make sure that the latest history data is loaded when using a script?

[Marbo]

Hey guys,

I made this little test-script:

void OnStart() {
   Alert(iTime("USDTHB", 60, 1));
}

The result was a date from 2018. When I started the script once again, the correct time and date was printed.

I know this is because I never look at USDTHB and the history is not loaded in the background.

What can I do in the script to make sure that the correct time and date is displayed when receiving data from pairs/timeframes I haven't looked at a long time?

[William Roeder]

On MT4: Unless the current chart is that specific pair/TF referenced, you must handle 4066/4073 errors before accessing candle/indicator values.
          Download history in MQL4 EA - Forex Calendar - MQL4 programming forum - Page 3 #26 № 4

[Marbo]

William Roeder:
On MT4: Unless the current chart is that specific pair/TF referenced, you must handle 4066/4073 errors before accessing candle/indicator values.
          Download history in MQL4 EA - Forex Calendar - MQL4 programming forum - Page 3 #26 № 4

Thanks a lot! I will implement this download history routine in my code.

[Marbo]

Marbo:

Thanks a lot! I will implement this download history routine in my code.

Because I need to implement it into a script I made these changes. Can I be sure that after the WHILE-loop all histories are loaded or do I miss something?

string symbol[] = {"AUDCAD", "AUDCHF", "AUDJPY", "AUDNZD", "AUDUSD",
                   "CADCHF", "CADJPY", "CHFJPY", "EURAUD", "EURCAD",
                   "EURCHF", "EURGBP", "EURJPY", "EURNZD", "EURUSD",
                   "GBPAUD", "GBPCAD", "GBPCHF", "GBPJPY", "GBPNZD",
                   "GBPUSD", "NZDCAD", "NZDCHF", "NZDJPY", "NZDUSD",
                   "USDCAD", "USDCHF", "USDJPY", "XAGUSD", "XAUUSD",
                   "XTIUSD", "DE30",   "US30",   "US500",  "USTEC"};

//+------------------------------------------------------------------+
//| Script program start function                                    |
//+------------------------------------------------------------------+
void OnStart() {
//---
   int s=0;
   while (s<ArraySize(symbol)-1 && !IsStopped()) {
      ResetLastError();
      datetime refresh=iTime(symbol[s], PERIOD_M15, 0);
      if (_LastError==0 && refresh!=0) s++;
   }

[Marbo]

Marbo:

Because I need to implement it into a script I made these changes. Can I be sure that after the WHILE-loop all histories are loaded or do I miss something?

I think it's better to show the complete code. This script should just scan for inside candles.

tring symbol[] = {"AUDCAD", "AUDCHF", "AUDJPY", "AUDNZD", "AUDUSD",
                   "CADCHF", "CADJPY", "CHFJPY", "EURAUD", "EURCAD",
                   "EURCHF", "EURGBP", "EURJPY", "EURNZD", "EURUSD",
                   "GBPAUD", "GBPCAD", "GBPCHF", "GBPJPY", "GBPNZD",
                   "GBPUSD", "NZDCAD", "NZDCHF", "NZDJPY", "NZDUSD",
                   "USDCAD", "USDCHF", "USDJPY", "XAGUSD", "XAUUSD",
                   "XTIUSD", "DE30",   "US30",   "US500",  "USTEC"};

//+------------------------------------------------------------------+
//| Script program start function                                    |
//+------------------------------------------------------------------+
void OnStart() {
//---
   int s=0;
   int tf=PERIOD_M15;
   while (s<ArraySize(symbol)-1 && !IsStopped()) {
      ResetLastError();
      datetime refresh=iTime(symbol[s], tf, 0);
      if (_LastError==0 && refresh!=0) s++;
      else Print(symbol[s]+" M"+(string)tf+": "+(string)_LastError);
   }

   for (s=0; s<ArraySize(symbol); s++) {
      if (iHigh(symbol[s], tf, 1)<iHigh(symbol[s], tf, 2) && iLow(symbol[s], tf, 1)>iLow(symbol[s], tf, 2)) {
         long chartID=ChartOpen(symbol[s], tf);
      }
   }
}