How to access bar data before OnBarUpdate() begins

[klopfgeist]

I apologize in advance for what is probably a question answered elsewhere, but I have tried searching, and I can't think up the right search term.

I want to access bar data, such as highs, lows, timestamps, etc. from all/any bar in the data series of my instrument before OnBarUpdate() begins, or possibly as a first act once it begins. Max() and Min() look back a specified number of bars from whatever bar OnBarUpdate() is processing. OnBarUpdate() does not seem to be able to look ahead, but the data for all the bars that are in the chart already exists, so data from the most recently formed bar/last bar in the chart should be available when OnBarUpdate() begins on the first bar. And for all the bars in between.

So, to sum up, I want to know how to access the data for all the bars in the chart before OnBarUpdate() begins going through the bars.

An example returning the date of the last bar in a chart would be very helpful.

And also, just out of curiosity, can OnBarUpdate() be called more than once in an indicator?

Thanks for your help,
Klopfgeist

[NinjaTrader_Austin]

Hello there, unfortunately I'm not sure I understand your question. OnBarUpdate() is called whenever there is some bar action, like after a bar completes building if Calculate On Bar Close is set to true. If it is set to false, then OnBarUpdate() will be called once for every bar before the live data, and then on every tick for the incoming data.

OnBarUpdate() will always refer to the most current bar, and you can get the data from whatever bar you want by referencing the bars back value. To get the high 4 bars back, for example, you could call High[4].

OnBarUpdate() is not called for every bar on a chart every time a new bar is formed. If COBC = true, there will be one OnBarUpdate() for each bar on the chart.

You cannot access ("I want to know how to access the data for all the bars in the chart before OnBarUpdate() begins going through the bars") a bar before OnBarUpdate() "creates" the bar, because it does not exist yet.

OnBarUpdate() isn't necessarily "called", the method is "called" whenever there is an update to the bar. It would not make sense to duplicate the OnBarUpdate() method because then the same exact events would occur twice in your indicator.

Lastly, to get the date of the last bar on a chart, you can reference Time[0]:

DateTime mostRecentBar = Time[0];