Structs mess with things, and I can't see why...
Update:
This is even stranger than I thought. It seems that even looking at the contents of a struct means the file won't write:
struct ShootRecord { bool is_overshoot; double level; };
In OnDeInit I try to write the contents of the first element of an array of ShootRecord (my struct):
void OnDeinit(const int reason) { int h=FileOpen("test.csv",FILE_WRITE|FILE_ANSI|FILE_CSV,","); if(h==INVALID_HANDLE) { Comment("Error opening file"); } ShootRecord shoot = overshoots[0]; double d = shoot.level; string test = DoubleToString(d, 5); Comment("test: " + test); FileWrite(h, test); FileClose(h); }
The variable 'test' appears correctly in the debugger watch list and renders fine as a comment on the screen. However the file is always empty. If I substitute an actual double into the line, rather than accessing the struct, like this:
ShootRecord shoot = overshoots[0]; double d = 0.0258644; //double d = shoot.level;
then the file still fails to write (!!!!), but if I remove the (unnecessary) assignment to the struct:
//ShootRecord shoot = overshoots[0]; double d = 0.0258644; //double d = shoot.level;
then the FileWrite works fine.
This is bizarre. I have spent a day reading forum posts without finding any references to this behaviour. There is no error generated (I have used _LastError), and if you step through in debug, everything looks fine.
So it seems to me that even mentioning a struct is enough to kill the FileWrite. What is going on?
Update:
This is even stranger than I thought. It seems that even looking at the contents of a struct means the file won't write:
In OnDeInit I try to write the contents of the first element of an array of ShootRecord (my struct):
The variable 'test' appears correctly in the debugger watch list and renders fine as a comment on the screen. However the file is always empty. If I substitute an actual double into the line, rather than accessing the struct, like this:
then the file still fails to write (!!!!), but if I remove the (unnecessary) assignment to the struct:
then the FileWrite works fine.
This is bizarre. I have spent a day reading forum posts without finding any references to this behaviour. There is no error generated (I have used _LastError), and if you step through in debug, everything looks fine.
So it seems to me that even mentioning a struct is enough to kill the FileWrite. What is going on?
//+------------------------------------------------------------------+ //| StructArray.mq5 | //| Copyright 2020, MetaQuotes Software Corp. | //| https://www.mql5.com | //+------------------------------------------------------------------+ #property copyright "Copyright 2020, MetaQuotes Software Corp." #property link "https://www.mql5.com" #property version "1.00" //+------------------------------------------------------------------+ //| Expert initialization function | //+------------------------------------------------------------------+ struct overshootstruct { double c; double d; overshootstruct() { c=d=0.00; } ~overshootstruct() {} }; struct Test { double a; double b; Test() { a=b=0.00; } ~Test() {} }; int OnInit() { overshootstruct overshoot[]; Test test_a[]; for(int i=0;i<10;i++) { ArrayResize(overshoot,i+1); overshoot[i].c = (double)(i+1); overshoot[i].d = (double)(i+2); } ArrayPrint(overshoot); ArrayResize(test_a,2); test_a[0].a = 1.23; test_a[0].b = 2.34; test_a[1].a = 1.23; test_a[1].b = 2.34; overshoot[0].c = test_a[0].a; overshoot[0].d = test_a[0].b; ArrayPrint(overshoot); Print("array struct of test_a size is ",ArraySize(test_a)); Print("array struct of overshoot is ",ArraySize(overshoot)); int h=FileOpen("test.csv",FILE_WRITE|FILE_ANSI|FILE_CSV,","); if(h==INVALID_HANDLE) { Comment("Error opening file"); } int _size = ArraySize(overshoot); PrintFormat("%s file is available for writing","test.csv"); for (int i=0;i<_size;i++) { FileWrite(h, "fubar"); } PrintFormat("File path: %s\\Files\\",TerminalInfoString(TERMINAL_DATA_PATH)); FileClose(h); //--- return(INIT_SUCCEEDED); }
KO 0 23:03:13.721 Tester expert file added: Experts\StructArray.ex5. 16721 bytes loaded IH 0 23:03:13.742 Tester initial deposit 10000000.00 USD, leverage 1:500 IM 0 23:03:13.742 Tester successfully initialized JI 0 23:03:13.742 Network 16 Kb of total initialization data received FP 0 23:03:13.742 Tester Intel Xeon E5-2686 v4 @ 2.30GHz, 8191 MB KE 0 23:03:13.777 Symbols EURUSD: symbol to be synchronized HQ 0 23:03:13.778 Symbols EURUSD: symbol synchronized already, 18 bytes received MP 0 23:03:13.781 History EURUSD: history synchronization started LG 0 23:03:13.786 History EURUSD: load 27 bytes of history data to synchronize in 0:00:00.002 PR 0 23:03:13.786 History EURUSD: history synchronized from 1999.01.04 to 2020.08.21 NE 0 23:03:13.787 Ticks EURUSD: ticks synchronization started RR 0 23:03:13.788 Ticks EURUSD: load 34 bytes of tick data to synchronize in 0:00:00.000 DO 0 23:03:13.788 Ticks EURUSD: history ticks synchronized from 2019.03.29 to 2020.08.21 LH 0 23:03:13.964 History EURUSD,M15: history cache allocated for 40787 bars and contains 40650 bars from 2019.01.02 09:00 to 2020.08.20 23:45 MJ 0 23:03:13.965 History EURUSD,M15: history begins from 2019.01.02 09:00 OE 0 23:03:13.976 Tester EURUSD,M15 (XMGlobal-MT5 2): generating based on real ticks KN 0 23:03:13.976 Tester testing with execution delay 251 milliseconds OI 0 23:03:13.976 Tester EURUSD,M15: testing of Experts\StructArray.ex5 from 2020.08.21 00:00 to 2020.08.23 00:00 started EJ 0 23:03:14.015 StructArray (EURUSD,M15) 2020.08.21 00:00:00 [c] [d] CP 0 23:03:14.015 StructArray (EURUSD,M15) 2020.08.21 00:00:00 [0] 1.00000 2.00000 FM 0 23:03:14.015 StructArray (EURUSD,M15) 2020.08.21 00:00:00 [1] 2.00000 3.00000 IJ 0 23:03:14.015 StructArray (EURUSD,M15) 2020.08.21 00:00:00 [2] 3.00000 4.00000 DG 0 23:03:14.015 StructArray (EURUSD,M15) 2020.08.21 00:00:00 [3] 4.00000 5.00000 GL 0 23:03:14.015 StructArray (EURUSD,M15) 2020.08.21 00:00:00 [4] 5.00000 6.00000 JI 0 23:03:14.015 StructArray (EURUSD,M15) 2020.08.21 00:00:00 [5] 6.00000 7.00000 MF 0 23:03:14.015 StructArray (EURUSD,M15) 2020.08.21 00:00:00 [6] 7.00000 8.00000 HS 0 23:03:14.015 StructArray (EURUSD,M15) 2020.08.21 00:00:00 [7] 8.00000 9.00000 FI 0 23:03:14.015 StructArray (EURUSD,M15) 2020.08.21 00:00:00 [8] 9.00000 10.00000 NE 0 23:03:14.015 StructArray (EURUSD,M15) 2020.08.21 00:00:00 [9] 10.00000 11.00000 ES 0 23:03:14.015 StructArray (EURUSD,M15) 2020.08.21 00:00:00 [c] [d] IO 0 23:03:14.015 StructArray (EURUSD,M15) 2020.08.21 00:00:00 [0] 1.23000 2.34000 FD 0 23:03:14.015 StructArray (EURUSD,M15) 2020.08.21 00:00:00 [1] 2.00000 3.00000 IQ 0 23:03:14.015 StructArray (EURUSD,M15) 2020.08.21 00:00:00 [2] 3.00000 4.00000 DN 0 23:03:14.015 StructArray (EURUSD,M15) 2020.08.21 00:00:00 [3] 4.00000 5.00000 GK 0 23:03:14.015 StructArray (EURUSD,M15) 2020.08.21 00:00:00 [4] 5.00000 6.00000 JP 0 23:03:14.015 StructArray (EURUSD,M15) 2020.08.21 00:00:00 [5] 6.00000 7.00000 MM 0 23:03:14.015 StructArray (EURUSD,M15) 2020.08.21 00:00:00 [6] 7.00000 8.00000 HJ 0 23:03:14.015 StructArray (EURUSD,M15) 2020.08.21 00:00:00 [7] 8.00000 9.00000 FF 0 23:03:14.015 StructArray (EURUSD,M15) 2020.08.21 00:00:00 [8] 9.00000 10.00000 NL 0 23:03:14.015 StructArray (EURUSD,M15) 2020.08.21 00:00:00 [9] 10.00000 11.00000 HE 0 23:03:14.015 StructArray (EURUSD,M15) 2020.08.21 00:00:00 array struct of test_a size is 2 IG 0 23:03:14.015 StructArray (EURUSD,M15) 2020.08.21 00:00:00 array struct of overshoot is 10 RO 0 23:03:14.016 StructArray (EURUSD,M15) 2020.08.21 00:00:00 test.csv file is available for writing NL 0 23:03:14.016 StructArray (EURUSD,M15) 2020.08.21 00:00:00 File path: C:\Users\Administrator\AppData\Roaming\MetaQuotes\Tester\BB16F565FAAA6B23A20C26C49416FF05\Agent-127.0.0.1-3000\Files\
Consult this (mql5 code add property strict if you use it in mql4)
struct shoots { bool set; double value; datetime time; shoots(void){set=false;value=0;time=0;} }; shoots ShootsArray[]; int OnInit() { //--- //fill up with random data ArrayResize(ShootsArray,20,0); //fill half for(int rd=0;rd<10;rd++) { //irrelevant stuff to your issue just getting data ,ignore from here ... ResetLastError(); int error_sum=0; double h=iHigh(_Symbol,_Period,rd+1); error_sum+=GetLastError(); datetime t=iTime(_Symbol,_Period,rd+1); error_sum+=GetLastError(); if(error_sum==0) { //...until here //fill your struct array ShootsArray[rd].set=true;//has data ShootsArray[rd].value=h;//high ShootsArray[rd].time=t;//time } } //fill up with random data ends here //save int method=1; //method 1 Human Readable Format : [i dont know if the ea can load it,havent tested/needed it] if(method==1) { int fop=FileOpen("test_struct_array.csv",FILE_WRITE|FILE_ANSI|FILE_CSV,","); if(fop==INVALID_HANDLE){Alert("Cant create file");ExpertRemove();} if(fop!=INVALID_HANDLE) { //header FileWrite(fop,"Set","Time","Value"); for(int x=0;x<ArraySize(ShootsArray);x++) { FileWrite(fop,ShootsArray[x].set,ShootsArray[x].time,ShootsArray[x].value); } FileClose(fop); } } //method 1 Human Readable Format ends here //method 2 ,save load capacity if(method==2) { int fop=FileOpen("test_struct_array.extention",FILE_WRITE|FILE_BIN); if(fop==INVALID_HANDLE){Alert("Cant create file");ExpertRemove();} if(fop!=INVALID_HANDLE) { FileWriteArray(fop,ShootsArray,0,ArraySize(ShootsArray)); FileClose(fop); } } //method 2 ,save load capacity ends here //--- return(INIT_SUCCEEDED); } //+------------------------------------------------------------------+ //| Expert deinitialization function | //+------------------------------------------------------------------+ void OnDeinit(const int reason) { //--- ArrayFree(ShootsArray); }
Thank you kind stranger.
The main issue was that when I didn't use the struct, the file was correctly written to the Terminal Files folder (presumably as well as the Tester/Files folder), so I was expecting to look in there each time.
When I DID use the struct, the file was only written to the Tester folder. I don't know why. However your tracing lines of code really helped me isolate what was happening.
I also don't yet understand the last properties (methods?) of the structs you used (probably because I am coming from C# not Cpp), but I am going to look them up now to see whether they also make a difference or are not required.
Much appreciated.
Thank you kind stranger.
The main issue was that when I didn't use the struct, the file was correctly written to the Terminal Files folder (presumably as well as the Tester/Files folder), so I was expecting to look in there each time.
When I DID use the struct, the file was only written to the Tester folder. I don't know why. However your tracing lines of code really helped me isolate what was happening.
I also don't yet understand the last properties (methods?) of the structs you used (probably because I am coming from C# not Cpp), but I am going to look them up now to see whether they also make a difference or are not required.
Much appreciated.
You are welcome , the method int is just for testing ,its not required .
Just out of curiosity, do you really indent your code like this or is your translator modifying your indentations?
ehehe ,yeah ,its a silly leftover from coding with notepad .
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Why does this not work? overshoots is an array of struct...
but this does.
Using the debugger I can see that _size gets correctly set as the size of the array called overshoots. So it is an integer and is equal to 12.
More struct weirdness below...