Exemplo MQL4

//+------------------------------------------------------------------+
//|                                              PastebinExemplo.mq4 |
//|                            Copyright 2015, Wemerson C. Guimarães |
//+------------------------------------------------------------------+
#property copyright "Copyright 2015, Wemerson C. Guimarães"
#property version   "1.00"
#property strict
#property indicator_separate_window
//+------------------------------------------------------------------+
//| Custom indicator initialization function                         |
//+------------------------------------------------------------------+
int OnInit()
  {
//--- indicator buffers mapping

//---
   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[])
  {
//---

//--- return value of prev_calculated for next call
   return(rates_total);
  }
//+------------------------------------------------------------------+