How NinjaTrader detects (forms) BarClose event?

[ttodua]

lets say, we have indicator set to Calculate.OnBarClose.
this means to catch the closing tick/update of the bar. But my question is how that happens?
i.e. we have indicator:

Print(Close[0]);
Print(Volume[0]);

for example, we are on 1 minute chart, and incoming ticks/updates has happened in this way:

14:47:54 (price 103.25)
14:47:57 (price 103.55)
14:48:04 (price 104.64)

so, at what time would "BarClose" event triggers or when it triggers, what price would be printed?

if that trigger happens at 14:48:04, then it will be the "first tick of bar" event, not the "last-tick of bar" update.
if that trigger happens at ..:47:57 , then how NT knows that it would be the last tick of the bar?
if that trigger happens at ..:48:00 (while actually there has not happened any incoming tick/update), then what would be price or volume at that moment, how NT forms that?

I am interested how NT works with regard to this subject..

[NinjaTrader_ChrisL]

Hi ttodua, thanks for your note.

When a script runs on bar close it does not catch the last tick of the bar, it has no synchronicity with the incoming ticks. Only a OnEachTick script is guaranteed to be called in sync with incoming ticks. A time based bar with an OnBarClose script will just close when an internal timer ticks.