RemoveLastBar() vs UpdateBar()

[fx.practic]

Hello.

I searched across the manuals and forum, but do not catch: why to remove bar, if we can update all it's prices and volume instead?

[NinjaTrader_ChrisL]

Hi fx.practic, thanks for your note.

RemoveLastBar is used to repaint the open of a bar. UpdateBar is unable to modify the open price.

Please let me know if I can assist any further.

[fx.practic]

Thanks a lot, Chris!
One of the most clear answers ever!

I
Am I clearly understand, that AddBar() impact all all scripts, using this bars series:
1. Triggers OnBarUpdate() for scripts Calculated.OrBarClose.
2. Increment CurrentBar index.
3. Set IsFirstTickOfBar to true.
4. Something else....

?

[NinjaTrader_ChrisL]

Hi fx.practic, thanks for the follow-up.

1. Yes, AddBar will trigger the OnBarUpdate method for all scripts running on the bar series.
2. Yes, AddBar will increment CurrentBar.
3. AddBar will set IsFirstTickOfBar to true in a Calculate.OnEachTick or Calculate.OnPriceChange script only.

Kind regards,

ChrisL

[fx.practic]

And what if to RemoveLastBar() without adding new one - does it triggers any events?

[NinjaTrader_ChrisL]

Hi fx.practic, thanks for your reply.

If one calls RemoveLastBar they are mostly always going to call AddBar right after to update the bar with new values. One would need to make a test script and see exactly what events trigger.

Please let me know if I can assist any further.

[fx.practic]

Thank you, Chris.
Once more question: why RemoveLastBar(), why not UpdateBar() with ability updating Open price?
Is there any reason for current design?

[NinjaTrader_ChrisL]

Hi fx.practic, thanks for your patience.

UpdateBar() is intended to change values of a bar that change over time and the open price obviously doesn't do this normally. The Renko and LineBreak bars are the only defaults that would need to change their open price. I can submit a feature request to request the ability to change the open price of a bar through UpdateBar.

Please let me know if I can assist any further.

[fx.practic]

Please, don't.
I've just asked to be familiar with general logic.
I'd wish to save development resource for something really useful.

Thanks again, Chris.