Custom Indicator not drawing when timeframe changed

[dhermanus]

Hi All,

I've written a test custom indicator that uses 2 MA. It drew the indicator fine when I first attached it to a chart

however when I changed the timeframe. It somehow only draw the last bar and continue from the latest bar.

Please help.

PS. There's no error in the expert tab. 

Here's the code.

#property copyright "Copyright 2021, Teststyle"
#property link      "https://www.mql5.com"
#property version   "1.00"
#property indicator_separate_window
#property indicator_buffers 1
#property indicator_plots   1
//--- plot MADiff
#property indicator_label1  "MADiff"
#property indicator_type1   DRAW_LINE
#property indicator_color1  clrRed
#property indicator_style1  STYLE_SOLID
#property indicator_width1  1
//--- input parameters
input int      MAFast=10;
input int      MASlow=20;
//--- indicator buffers
double         MADiffBuffer[];
//+------------------------------------------------------------------+
//| Custom indicator initialization function                         |
//+------------------------------------------------------------------+
int OnInit()
  {
  
  
//--- indicator buffers mapping
   SetIndexBuffer(0,MADiffBuffer,INDICATOR_DATA);
   
//---
   return(INIT_SUCCEEDED);
  }
//+------------------------------------------------------------------+
//| Custom indicator iteration function                              |
//+------------------------------------------------------------------+
int OnCalculate(const int rates_total,
                const int prev_calculated,
                const datetime &time[],
                const double &open[],
                const double &high[],
                const double &low[],
                const double &close[],
                const long &tick_volume[],
                const long &volume[],
                const int &spread[])
  {
//---
   
   
   double ma_fast[];
   double ma_slow[];
   ArraySetAsSeries(close,true);
   ArraySetAsSeries(MADiffBuffer,true);
   ArraySetAsSeries(ma_fast,true);
   ArraySetAsSeries(ma_slow,true);
   
   int bars = rates_total -1;
   if (prev_calculated>0) bars = rates_total - prev_calculated;
   
//   
//   double l_close[];
//   
//   ArrayCopy(l_close,close,0,0,WHOLE_ARRAY);
   
   
   int h_maFast = iMA(_Symbol,_Period,MAFast,0,MODE_SMA,PRICE_CLOSE );
   int h_maSlow = iMA(_Symbol,_Period,MASlow,0,MODE_SMA,PRICE_CLOSE);
   
   CopyBuffer(h_maFast,0,0,bars+1,ma_fast);
   CopyBuffer(h_maSlow,0,0,bars+1,ma_slow);
   
  
   for (int i = bars; i >= 0; i--)
   {
      
      MADiffBuffer[i] = ma_slow[i] >= ma_fast[i] ? ma_slow[i] - ma_fast[i]: ma_fast[i] -ma_slow[i];
      
   }
   
  
   
   
   
//--- return value of prev_calculated for next call
   return(rates_total);
  }
//+------------------------------------------------------------------+

[Vladimir Karputov]

You are making a gross mistake - you CREATE AN INDICATOR HANDLE AT EVERY TICK !!! This is a gross mistake! According to MQL5 style, HANDLE INDICATOR SHOULD BE CREATED ONLY ONCE and done in OnInit.

See the documentation for an example: iMA

I also recommend creating an indicator template using the 'MQL5 Wizard'.

[dhermanus]

@Vladimir Karputov  you are right. Moved it to the OnInit event and it worked. thanks. 

[Vladimir Karputov]

dhermanus # :
@Vladimir Karputov   you are right. Moved it to the OnInit event and it worked. thanks. 

Please attach your code (using the button ) and a screenshot of the indicator's operation - I'm interested to see what happened.

[dhermanus]

Here it is. Just moved the handle declaration to the OnInit section.