barstate.isconfirmed in MQL5: act once per closed bar

The Pine Script v6 code

An overlay indicator that marks the bars whose close crossed above a 20 SMA, only once the bar has closed, and sends an alert at that moment.

Checked by Edgoro Pine Check with no errors and no warnings. Pine Check is a static checker, not TradingView's compiler, and this script was not run in TradingView.

//@version=6
indicator("Close above SMA, closed bars only", overlay = true)

len = input.int(20, "SMA length", minval = 1)

sma = ta.sma(close, len)
crossUp = ta.crossover(close, sma)
// Only once the bar has closed, so a signal can't appear and then vanish in real time
signal = crossUp and barstate.isconfirmed

plot(sma, "SMA", color.orange, 2)
plotshape(signal, "Close crossed above SMA", shape.labelup, location.belowbar, color.teal, size = size.tiny)

if signal
    alert("Close crossed above the SMA on " + syminfo.ticker, alert.freq_once_per_bar_close)

The MQL5 program

An Expert Advisor that checks the same cross once per bar, on the closed bar, and alerts with a pop-up and optionally a push notification. It never trades.

Save it as MQL5/Experts/barstate-isconfirmed-new-bar.mq5 and compile it in MetaEditor (F7): 0 errors, 0 warnings.

//+------------------------------------------------------------------+
//| barstate.isconfirmed in an Expert Advisor: act once per bar,     |
//| on the bar that just closed. This EA only alerts, it never       |
//| trades. Save in MQL5/Experts and compile (F7).                   |
//+------------------------------------------------------------------+
input int  InpSmaLen = 20;    // SMA length
input bool InpPopup  = true;  // Pop-up alert
input bool InpPush   = false; // Push notification to the MetaTrader app

int      smaHandle   = INVALID_HANDLE;
datetime lastBarTime = 0;

int OnInit()
  {
   if(InpSmaLen < 1)
      return INIT_PARAMETERS_INCORRECT;
   smaHandle = iMA(_Symbol, _Period, InpSmaLen, 0, MODE_SMA, PRICE_CLOSE);
   if(smaHandle == INVALID_HANDLE)
      return INIT_FAILED;
   // Like a Pine alert, start with the next bar that closes, not with history
   lastBarTime = iTime(_Symbol, _Period, 0);
   return INIT_SUCCEEDED;
  }

void OnDeinit(const int reason)
  {
   IndicatorRelease(smaHandle);
  }

// True on the first tick of a new bar: the previous bar (shift 1) has just closed
bool IsNewBar()
  {
   datetime t = iTime(_Symbol, _Period, 0);
   if(t == 0 || t == lastBarTime)
      return false;
   lastBarTime = t;
   return true;
  }

void OnTick()
  {
   if(!IsNewBar())
      return;

   double sma[];
   ArraySetAsSeries(sma, true);  // [0] = bar 1 (just closed), [1] = bar 2
   double c1 = iClose(_Symbol, _Period, 1);
   double c2 = iClose(_Symbol, _Period, 2);
   if(CopyBuffer(smaHandle, 0, 1, 2, sma) != 2 || c1 == 0.0 || c2 == 0.0)
     {
      lastBarTime = 0;  // data not ready: evaluate this bar again on the next tick
      return;
     }

   // ta.crossover(close, sma) on the closed bar; the closed bar is barstate.isconfirmed
   if(!(c1 > sma[0] && c2 <= sma[1]))
      return;

   string msg = StringFormat("Close crossed above the SMA(%d) on %s, bar of %s", InpSmaLen, _Symbol,
                             TimeToString(iTime(_Symbol, _Period, 1), TIME_DATE | TIME_MINUTES));
   Print(msg);
   if(InpPopup)
      Alert(msg);
   if(InpPush && !SendNotification(msg))
      Print("Push notification failed, error ", GetLastError());
  }
//+------------------------------------------------------------------+

Line by line

barstate.isconfirmed

bool IsNewBar()
  {
   datetime t = iTime(_Symbol, _Period, 0);
   if(t == 0 || t == lastBarTime)
      return false;
   lastBarTime = t;
   return true;
  }

sma = ta.sma(close, len)

ArraySetAsSeries(sma, true);
CopyBuffer(smaHandle, 0, 1, 2, sma);

crossUp = ta.crossover(close, sma)
signal = crossUp and barstate.isconfirmed

double c1 = iClose(_Symbol, _Period, 1);
double c2 = iClose(_Symbol, _Period, 2);
if(!(c1 > sma[0] && c2 <= sma[1]))
   return;

alert("Close crossed above the SMA on " + syminfo.ticker,
  alert.freq_once_per_bar_close)

Alert(msg);
if(InpPush && !SendNotification(msg))
   Print("Push notification failed, error ", GetLastError());

// Pine alerts only fire in real time

lastBarTime = iTime(_Symbol, _Period, 0);  // OnInit

// Pine waits for the data

if(CopyBuffer(...) != 2 || c1 == 0.0 || c2 == 0.0)
  {
   lastBarTime = 0;  // evaluate again on the next tick
   return;
  }

Pitfalls

• The first tick can be late. The new bar is noticed when a tick arrives. On a quiet market that can be seconds or minutes after the close; Pine's barstate.isconfirmed fires on the bar's last tick. Same values, later moment.
• Bars without ticks. If no tick arrives during a whole bar, that bar doesn't exist in MetaTrader 5, so shift 2 can be further back in time than the clock suggests.
• The tester's "Open prices only". That mode only runs the first tick of each bar. An EA that reads only closed bars behaves the same there and live; one that reads shift 0 doesn't, which is how an MT5 backtest repaints. See MT5 Strategy Tester modelling modes.
• rates_total > prev_calculated in an indicator is also true on the first call and whenever history is reloaded. Compare bar times instead, as the alert indicator does.
• Restarts. lastBarTime lives in memory: after a restart the EA starts again from the current bar. Fine for alerts; for trades, check the open positions or the deal history rather than a variable.

Checking that both give the same values

1. In TradingView, add the Pine indicator and create an alert on "Any alert() function call"; in MetaTrader 5, attach the EA to the same symbol and timeframe. A 1-minute chart gives signals quickly.
2. Both should fire after the same bar closes, MetaTrader 5 on the next tick.
3. On history, run the EA in the Strategy Tester with visual mode on: the Journal prints each signal with its bar time, to compare with the labels on the TradingView chart.

The same idea in a custom indicator

An indicator recalculates the forming bar on every tick, at index rates_total - 1. Values there can still change, like Pine's real-time bar. To keep only confirmed signals, loop over closed bars, for(int i = start; i < rates_total - 1; i++), and decide alerts on rates_total - 2, remembering its time[] so later ticks don't repeat them. The pivot indicator confirms pivots that way.

These programs show one technique each; they are not trading systems, and none of this is a recommendation to trade. Trading involves substantial risk of loss and is not suitable for every investor. Edgoro is a software tool, not a broker or financial adviser: nothing it produces is investment advice, and past or backtested performance does not guarantee future results.