The indicator reads signals to buy and sell from the file located in the subdirectory of the local terminal folder and then displays these signals in the form of up and down directed arrows. To get the file with signals you need preliminary run the Demo_FileWrite script. The terminal local folder location can be obtained calling the TerminalInfoString() function.
PrintFormat("The path to the terminal local folder: %s\\Files\\",TerminalInfoString(TERMINAL_DATA_PATH));To get data in addition to the FileReadDatetime() function, the indicator also uses the FileReadNumber() and the FileReadBool() functions.
Code:
#property indicator_chart_window #property indicator_buffers 2 #property indicator_plots  2 //---- plot Label1 #property indicator_label1  "UpSignal" #property indicator_type1  DRAW_ARROW #property indicator_color1  clrRed #property indicator_style1  STYLE_SOLID #property indicator_width1  4 //---- plot Label2 #property indicator_label2  "DownSignal" #property indicator_type2  DRAW_ARROW #property indicator_color2  clrRed #property indicator_style2  STYLE_SOLID #property indicator_width2  4 //--- parameters for reading data input string InpFileName="MACD.csv";  // file name input string InpDirectoryName="Data"; // directory name //--- global variables int      ind=0;      // index double  upbuff[];    // indicator buffer of up arrows double  downbuff[];  // indicator buffer of down arrows bool    sign_buff[]; // signal array (true - buy, false - sell) datetime time_buff[]; // array of signals arrival time int      size=0;      // size of signal arrays //+------------------------------------------------------------------+ //| Custom indicator initialization function                        | //+------------------------------------------------------------------+ int OnInit()   { //--- open the file   ResetLastError();   int file_handle=FileOpen(InpDirectoryName+"//"+InpFileName,FILE_READ|FILE_CSV);   if(file_handle!=INVALID_HANDLE)     {       PrintFormat("%s file is open for reading",InpFileName);       //--- first, read the number of signals       size=(int)FileReadNumber(file_handle);       //--- allocate memory for the arrays       ArrayResize(sign_buff,size);       ArrayResize(time_buff,size);       //--- read data from the file       for(int i=0;i<size;i++)         {         //--- signal time         time_buff[i]=FileReadDatetime(file_handle);         //--- signal value         sign_buff[i]=FileReadBool(file_handle);         }       //--- close the file       FileClose(file_handle);     }   else     {       PrintFormat("Failed to open %s file, Error code = %d",InpFileName,GetLastError());       return(INIT_FAILED);     } //--- binding the arrays   SetIndexBuffer(0,upbuff,INDICATOR_DATA);   SetIndexBuffer(1,downbuff,INDICATOR_DATA); //--- set the symbol code for drawing in PLOT_ARROW   PlotIndexSetInteger(0,PLOT_ARROW,241);   PlotIndexSetInteger(1,PLOT_ARROW,242); //---- set the indicator values that will not be seen in the chart   PlotIndexSetDouble(0,PLOT_EMPTY_VALUE,0);   PlotIndexSetDouble(1,PLOT_EMPTY_VALUE,0); //---   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[])   {   ArraySetAsSeries(time,false);   ArraySetAsSeries(high,false);   ArraySetAsSeries(low,false); //--- the loop for the bars that have not been handled yet   for(int i=prev_calculated;i<rates_total;i++)     {       //--- default value is 0       upbuff[i]=0;       downbuff[i]=0;       //--- check if any data is still present       if(ind<size)         {         for(int j=ind;j<size;j++)           {             //--- if dates coincide, use the value from the file             if(time[i]==time_buff[j])               {               //--- draw the arrow according to the signal               if(sign_buff[j])                   upbuff[i]=high[i];               else                   downbuff[i]=low[i];               //--- increase the counter               ind=j+1;               break;               }           }         }     } //--- return value of prev_calculated for next call   return(rates_total);   }