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MQL4 Script - open on new bar question

  • #1
  • First Post: Apr 25, 2018 8:31am Apr 25, 2018 8:31am
Hi,

Since there's an EA already running on my chart(s), I would like to have my script open three (or more or less, doesn't matter but 1+n, n>=0 trades when it is executed) trades, the first when it is executed on the chart and the rest one per new bar.

currently, this is how the logic looks like, however this only opens the first trade, stay on the chart but doesn't open the next few trades.
It's probably something stupid, but I'm tired and have looked at code most of my waking hours till now and I'm missing it.
Or, I can miss out on the logic entirely.

Either way, any help would be greatly appreciated.


Inserted Code
int ExtraTrades = 3;
datetime stopper=Time[0];
int counter = 1;
//+------------------------------------------------------------------+
//| Is new bar                                                       |
//+------------------------------------------------------------------+
bool IsNewBar() {
  if (stopper == Time[1])
  {
    stopper = Time[0];
    return true;
  }
  else
  {
    return false;
  }
}
//+------------------------------------------------------------------+
void start()
{
  while (counter <= ExtraTrades)
  {
    if (counter == 1)
    {
      OpenIt();
      counter++;
    }
    if (IsNewBar())
    {
      OpenIt();
      counter++;
    }
  }
  counter = 1;
}
  • #2
  • Apr 25, 2018 9:47am Apr 25, 2018 9:47am
Well, after some debugging, looks like the IsNewBar() isn't evaluating correctly.
I don't know why. Why would it work for an EA but not for a script?

Code now looks like this

Inserted Code
//+------------------------------------------------------------------+
//| Is new bar                                                       |
//+------------------------------------------------------------------+
bool IsNewBar() {
  if (stopper == Time[1])
  {
    stopper = Time[0];
    return true;
  }
  else
  {
    return false;
  }
}
//+------------------------------------------------------------------+
void start()
{
  OpenIt();
  while (counter <= ExtraTrades)
  {
    if (IsNewBar())
    {
      OpenIt();
    }
  }
}
  • #3
  • Apr 25, 2018 10:31am Apr 25, 2018 10:31am
Quoting Reamasesa
Why would it work for an EA but not for a script?
Scripts are (more) intended as run-once. AFAIK they do not get (price etc) updates. If you need fresh data, you have to poll it. Try something along this (pseudo) code:
Inserted Code
time = 0
count = 0
while count < target
    if time != iTime(...,0)
        if open()
            count++
        time = iTime(...,0)
    Sleep(100)
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  • #4
  • Apr 25, 2018 11:05am Apr 25, 2018 11:05am
Quoting rockit
{quote} Scripts are (more) intended as run-once. AFAIK they do not get (price etc) updates. If you need fresh data, you have to poll it. Try something along this (pseudo) code: time = 0 count = 0 while count < target if time != iTime(...,0) if open() count++ time = iTime(...,0) Sleep(100)
Thanks for replying.

I've replaced the IsNewBar with stopper !=iTime(Symbol(),PERIOD_CURRENT,0) but still, it's either not passing through the "if" or not updating.
I can't sleep it since it's going to run on Renko, I might miss a bar/entry out if the sleep is large enough.
  • #5
  • Edited 12:47pm Apr 25, 2018 11:49am | Edited 12:47pm
Quoting Reamasesa
{quote} Thanks for replying. I've replaced the IsNewBar with stopper !=iTime(Symbol(),PERIOD_CURRENT,0) but still, it's either not passing through the "if" or not updating. I can't sleep it since it's going to run on Renko, I might miss a bar/entry out if the sleep is large enough.
Unfortunately we have to do it "brute force" with RefreshRates(). MetaTrader is bad. This works:
Inserted Code
#property strict
void OnStart()
{
    datetime time = 0;
    int count = 0;
    int target = 3;
    while((count < target) && !IsStopped())
    {
        if(time != iTime(_Symbol,PERIOD_CURRENT,0))
        {
            count++;
            Print("time changed: ", count);
            time = iTime(_Symbol, PERIOD_CURRENT, 0);
        }
        Sleep(1);
        RefreshRates();
    }
}
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  • #6
  • Apr 25, 2018 2:24pm Apr 25, 2018 2:24pm
Quoting rockit
{quote} Unfortunately we have to do it "brute force" with RefreshRates(). MetaTrader is bad. This works: #property strict void OnStart() { datetime time = 0; int count = 0; int target = 3; while((count < target) && !IsStopped()) { if(time != iTime(_Symbol,PERIOD_CURRENT,0)) { count++; Print("time changed: ", count); time = iTime(_Symbol, PERIOD_CURRENT, 0); } Sleep(1); RefreshRates(); } }

Thanks you for that, had I seen it earlier it might have saved me the head butting against everything that came my way before I figured out the RefreshRates() was the culprit.

I've done it using the Bars function, not sure it's bullet proof but I think it does the trick, as well

Inserted Code
void start()
{
  OpenIt();
  RefreshRates();
  int nBars=Bars(Symbol(), PERIOD_CURRENT);
  while  (counter <= ExtraTrades)
  {
    RefreshRates();
    if (nBars < Bars(Symbol(), PERIOD_CURRENT))
    {
      OpenIt();
      nBars=Bars(Symbol(), PERIOD_CURRENT);
    }
  }
}
  • #7
  • Apr 25, 2018 2:44pm Apr 25, 2018 2:44pm
Inserted Code
static datetime T0;
//+------------------------------------------------------------------+
int OnInit()
  {
   T0=Time[0]; // or T0 = 0;  ???
   return(INIT_SUCCEEDED);
  }
//+------------------------------------------------------------------+
void OnTick()
  {
   if(T0!=Time[0])
     {
      T0=Time[0];
      RefreshRates();
      OpenIt();
     }
..............................
  }
  • #8
  • Apr 25, 2018 3:30pm Apr 25, 2018 3:30pm
Quoting IgorVM
static datetime T0; //+------------------------------------------------------------------+ int OnInit() { T0=Time[0]; // or T0 = 0; ??? return(INIT_SUCCEEDED); } //+------------------------------------------------------------------+ void OnTick() { if(T0!=Time[0]) { T0=Time[0]; RefreshRates(); OpenIt(); } .............................. }
Thanks, I'm doing something similar in my EA, I'm not sure OnTick is valid for a script, though.
  • #9
  • Apr 26, 2018 12:51am Apr 26, 2018 12:51am
Quoting Reamasesa
{quote} Thanks, I'm doing something similar in my EA, I'm not sure OnTick is valid for a script, though.
use OnStart() instead OnTick(), all works
instead
  • #10
  • Edited 3:56am Apr 26, 2018 2:08am | Edited 3:56am
Inserted Code
#property strict
#property show_inputs
input int ExtraTrades=10;
static datetime T0;
//+------------------------------------------------------------------+
void OnStart()
  {
   int counter=0;
   T0=0;
   while(!IsStopped() && counter<ExtraTrades)
     {
      if(T0!=Time[0])
        {
         T0=Time[0];
         RefreshRates();
         OpenIt();
         counter++;
         Sleep(1000);
        }
     }
  }
//+------------------------------------------------------------------+
  • #11
  • Apr 26, 2018 2:27am Apr 26, 2018 2:27am
Quoting Reamasesa
I've done it using the Bars function, not sure it's bullet proof but I think it does the trick, as well
Be advised that this method is not reliable, as MT stops updating bars count after max bars setting is achieved. So, the only! reliable method is to check time.
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  • #12
  • Apr 26, 2018 9:45am Apr 26, 2018 9:45am
Quoting rockit
{quote} Be advised that this method is not reliable, as MT stops updating bars count after max bars setting is achieved. So, the only! reliable method is to check time.
Yup, agreed, definitely don't use the Bars method. The most reliable way to to use SeriesInfoInteger and call it for the LASTBAR_DATE, check for errors, and if there are errors loop and ask again until your function times-out or you get a clean result. Here is an example of a MTF isNewBar function...

Inserted Code
#include <Arrays\ArrayObj.mqh>
class NewBars : public CObject
{
   ENUM_TIMEFRAMES m_timeframe;
   datetime m_last_bar_time;
public:
   NewBars(ENUM_TIMEFRAMES tf):m_timeframe(tf),m_last_bar_time(0){}  
   bool isNewBar()
   {
      uint ms = GetTickCount();
      datetime curr;
      do{
         ResetLastError();
         curr = (datetime)SeriesInfoInteger(_Symbol,m_timeframe,SERIES_LASTBAR_DATE);
      }while(_LastError != ERR_NO_ERROR && GetTickCount() - ms < 500);
      if(curr > 0 && _LastError == ERR_NO_ERROR && curr != m_last_bar_time)
      {
         bool res = true;
         if(m_last_bar_time == 0)
            res = false;
         m_last_bar_time = curr;
         return res;
      }
      return false;
   }  
   bool isMatching(ENUM_TIMEFRAMES tf){ return m_timeframe == tf ? true : false;}
};
bool isNewBar(const ENUM_TIMEFRAMES timeframe)
{
   static CArrayObj tfs;
   for(int i = tfs.Total()-1; i>=0; i--)
   {
      NewBars *tf = dynamic_cast<NewBars*>(tfs.At(i));
      if(tf.isMatching(timeframe))
         return tf.isNewBar();
   }
   tfs.Add(new NewBars(timeframe));
   return false;
}
  • #13
  • Edited 10:34am Apr 26, 2018 10:22am | Edited 10:34am
Quoting rockit
{quote} Be advised that this method is not reliable, as MT stops updating bars count after max bars setting is achieved. So, the only! reliable method is to check time.
It doesn't (stop updating)
Bars() exceeds max number of bars in cases when max bars setting is reached (and exceeded)

Attached Image (click to enlarge)
Click to Enlarge Name: example.jpg Size: 374 KB

  • #14
  • Apr 26, 2018 10:33am Apr 26, 2018 10:33am
Quoting Nicholishen
{quote} Yup, agreed, definitely don't use the Bars method. The most reliable way to to use SeriesInfoInteger and call it for the LASTBAR_DATE, check for errors, and if there are errors loop and ask again until your function times-out or you get a clean result. Here is an example of a MTF isNewBar function... #include <Arrays\ArrayObj.mqh> class NewBars : public CObject { ENUM_TIMEFRAMES m_timeframe; datetime m_last_bar_time; public: NewBars(ENUM_TIMEFRAMES tf):m_timeframe(tf),m_last_bar_time(0){} bool isNewBar() { uint ms = GetTickCount(); datetime...
Thank you, you are very kind in providing this examples, here and on my other threads.
I understand what you've done here but the linguistics eludes me still as I am yet to learn the OO side of the MQL4.
I'm also not entirely sure your code will work inside the context of a script, but I'm not all that knowledgeable.
  • #15
  • Apr 26, 2018 10:34am Apr 26, 2018 10:34am
Quoting rockit
{quote} Be advised that this method is not reliable, as MT stops updating bars count after max bars setting is achieved. So, the only! reliable method is to check time.
Thanks, I read contradicting replies in various threads so I wasn't sure but it was working for me so I figured "what the heck"
  • #16
  • Apr 26, 2018 10:35am Apr 26, 2018 10:35am
Quoting mladen
{quote} It doesn't (stop updating) Bars() exceeds max number of bars in cases when max bars setting is reached {image}
Thanks for replying, so am I right to use this Bars method or not? Feels like it's simpler then the Time method and I do like to keep things simple
  • #17
  • Apr 26, 2018 10:51am Apr 26, 2018 10:51am
Quoting Reamasesa
{quote} Thanks for replying, so am I right to use this Bars method or not? Feels like it's simpler then the Time method and I do like to keep things simple
Neither method is complicated :
Inserted Code
   static datetime _prevTime = 0;
          datetime _currTime = iTime(NULL,desired time frame,0);
          bool     _isNewBar = (_prevTime != _currTime);
               if (_isNewBar)   _prevTime  = _currTime;
  • #18
  • Apr 26, 2018 11:16am Apr 26, 2018 11:16am
Quoting mladen
{quote} Neither method is complicated : static datetime _prevTime = 0; datetime _currTime = iTime(NULL,desired time frame,0); bool _isNewBar = (_prevTime != _currTime); if (_isNewBar) _prevTime = _currTime;
Thanks, I had something similar in my script but it didn't work (posted earlier in first post) even when I added the RefreshRates().
I'll try again with your code, with added ResreshRates() inside and out of the loop so the script gets fresh information.
  • #19
  • Apr 26, 2018 12:36pm Apr 26, 2018 12:36pm
Inserted Code
// --- Global Variable ------------------------------------------------------------------
datetime ArrayTime[], LastTime;
 
void OnTick()
{
      if(NewBar(PERIOD_CURRENT))
      {
            // your code
 
       }
 
}
 
bool NewBar(int period)
{
   bool firstRun = false, newBar = false;
  
   ArraySetAsSeries(ArrayTime,true);
   CopyTime(Symbol(),period,0,2,ArrayTime);
   if(LastTime == 0) firstRun = true;
   if(ArrayTime[0] > LastTime)
  {
      if(firstRun == false) newBar = true;
      LastTime = ArrayTime[0];
   }
 
   return newBar;  
}
  • #20
  • Apr 26, 2018 1:32pm Apr 26, 2018 1:32pm
Also, check this code which is suitable for arbitrary time frames (detected with the first price quote):
Inserted Code
#property strict
void OnStart()
{
   datetime seconds = _Period * 60; // state any amount in seconds
   datetime t_last_recorded = 0; // for demonstration sake :D
   while(!IsStopped())
   {
      RefreshRates();
      datetime t = TimeCurrent(); // time of last known quote
      datetime t_normalized = t / seconds * seconds;
      if(t_normalized > t_last_recorded)
      {
         // new bar
         printf("new bar!");
         t_last_recorded = t_normalized;
      }
      Sleep(1);
   }
}
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