Discussion of article "The checks a trading robot must pass before publication in the Market" - page 2

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Thank you, the article is very useful.

I am not very clear in the subtopic "Limiting the number of lots by one symbol" the code of the PositionVolume() function is given twice.
Just below is the description of the NewOrderAllowedVolume() function and its call:

double orders_volume_on_symbol=PendingsVolume(symbol);

Only the description of the PendingsVolume() function is nowhere to be seen in the article.

If instead of PendingsVolume() function the PositionVolume() function is given again by mistake, please correct it.

 
ok google, how to pass validation, no not like that, I need an example of a simple EA that can 100% pass validation to study its code and compare it with my own to find what can be an error, and even better, more details about validation - how it happens, what it does.
 

That's an interesting article, unfortunately there are too much errors (typo or even logical errors in the proposed code), and it will probably confuse more people than help them at some points.

1°

//+------------------------------------------------------------------+
//| Return the maximum allowed volume for an order on the symbol     |
//+------------------------------------------------------------------+
double NewOrderAllowedVolume(string symbol)
  {
   double allowed_volume=0;
//--- get the limitation on the maximal volume of an order
   double symbol_max_volume=SymbolInfoDouble(Symbol(),SYMBOL_VOLUME_MAX);
//--- get the limitation on the volume by a symbol
   double max_volume=SymbolInfoDouble(Symbol(),SYMBOL_VOLUME_LIMIT);

//--- get the volume of the open position by a symbol
   double opened_volume=PositionVolume(symbol);
   if(opened_volume>=0)
     {
      //--- if we have exhausted the volume
      if(max_volume-opened_volume<=0)
         return(0);

      //--- volume of the open position doesn't exceed max_volume
      double orders_volume_on_symbol=PendingsVolume(symbol);
      allowed_volume=max_volume-opened_volume-orders_volume_on_symbol;
      if(allowed_volume>symbol_max_volume) allowed_volume=symbol_max_volume;
     }
   return(allowed_volume);
  }

Logical error. If there is no position yet, you still have to check the pendings volume and calculate allowed volume. This code returns allowed_volume=0 if there is no position already opened without taking pendings into account.

2°

bool OrderModifyCheck(ulong ticket,double price,double sl,double tp)
  {
//--- select order by ticket
   if(orderinfo.Select(ticket))
     {
      //--- point size and name of the symbol, for which a pending order was placed
      string symbol=orderinfo.Symbol();
      double point=SymbolInfoDouble(symbol,SYMBOL_POINT);
      int digits=(int)SymbolInfoInteger(symbol,SYMBOL_DIGITS);
      //--- check if there are changes in the Open price
      bool PriceOpenChanged=(MathAbs(orderinfo.PriceOpen()-price)>point);
      //--- check if there are changes in the StopLoss level
      bool StopLossChanged=(MathAbs(orderinfo.StopLoss()-sl)>point);
      //--- check if there are changes in the Takeprofit level
      bool TakeProfitChanged=(MathAbs(orderinfo.TakeProfit()-sl)>tp);
      //--- if there are any changes in levels
      if(PriceOpenChanged || StopLossChanged || TakeProfitChanged)
         return(true);  // order can be modified      
      //--- there are no changes in the Open, StopLoss and Takeprofit levels
      else
      //--- notify about the error
         PrintFormat("Order #%d already has levels of Open=%.5f SL=.5f TP=%.5f",
                     ticket,orderinfo.StopLoss(),orderinfo.TakeProfit());
     }
//--- came to the end, no changes for the order
   return(false);       // no point in modifying 
  }

An other logical error. Changing a SL/TP by 1 point is allowed. It should be >=

+ typo error, should be "-tp)>=point);"

+ missing parameter (PrintFormat has for %, but only 3 parameters are provided).

3°

bool PositionModifyCheck(ulong ticket,double sl,double tp)

Similar error as point 2° above.

And same errors also in OrderModifyCheck() mql4 version.

Thanks for fixing these errors, please note I didn't check all the article in depth, so maybe there is more.

 

Some other comments about this article, but not related to errors this time, but more on my personal opinion :

Access violation

This error occurs when trying to address memory, the access to which is denied. In each such case, it is necessary to contact the developers via the Service Desk in your Profile or via the Contacts page.
  • Funnily enough, this has nothing to do in an article about users (coders) errors. An access violation means it's an error in Metaquotes code 

This type of errors is relatively rare, many of them have ready codes, that are designed to help in finding the cause.

Constant Value Description
ERR_INTERNAL_ERROR 4001 Unexpected internal error
ERR_WRONG_INTERNAL_PARAMETER 4002 Wrong parameter in the inner call of the client terminal function
  • Error codes are there to help, but "Unexpected internal error" is completely useless and "Wrong parameter in the inner call of the client terminal function" is really cryptic (at least to me).

Newcomers are recommended to read all the articles about error handling, as well as ask questions on the forum and in the article comments. Other more experienced members of the MQL5.community will help you figure out any unclear points. We hope that the information gathered in the article will help you create more reliable trading robots and in a shorter time.

  • I completely disagree with such practice, the Market is a commercial service proposed by Metaquotes, they should assume the support and don't rely on the community. That's not a professional approach following my view.

Despite the critics, I would like to thank Metaquotes for their great work on MT4/MT5, and encourage them to continue to increase their level of quality and professionalism.

 
Andrey Barinov:

This is the part that raises questions:

Why is required margin compared to Equity and not FreeMargin?

http://prntscr.com/dgd6s4

now what's wrong?

checks the margin, no enough money, does not trade, but does not let you raise the owl.

Снимка на екрана
Снимка на екрана
  • prnt.sc
Снимано с Lightshot
 
Please tell me how to be! I want to put out a product - Expert Advisor Assistant, which must be bound to open trades for it to work. Without binding there will be no trades in the tester and it will not pass the test
 
Have you tried it? Or was it just an offhand comment?
 
Vladislav Andruschenko:
Did you try it? Or did you just say that?
I did! It came up with a message that it didn't check out, no owls opened any trades! Well, he won't if he's an assistant.
 
Bogdan Bovykin:
I tried it! I got a message that it was not verified, not a single trade opened! Well, it won't open if it's an assistant.

If it is a utility, moderators check the EA personally.

The utility can be set up for the tester to open at least a couple of trades and accompany them as an assistant. It's not a problem.

 
Vladislav Andruschenko:

If it is a utility, moderators check the EA personally.

The utility can be set up for the tester to open at least a couple of trades and accompany them as an assistant. That's not a problem.

I mean, do you want to make it as a panel? And check it that way? Or what?

just open any trade manually at the moment and attach this EA to the chart to the ticket of the open order.

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