getExtremesFromAll property loads and iterates on all points in DOM and slows down performance of chart render and scroll. about highcharts

[TorsteinHonsi]

@tanmayshah95

Here's the OP demo with the fix applied, except a fixed width for consistent comparison: https://jsfiddle.net/highcharts/zwpj82gd/

On my machine, the rendering time is reduced from 826 ms to 24 ms.

[bm64]

Hello @tanmayshah95,

Thanks for reporting the issue. Unfortunately, I can't provide a workaround right now, but I will bring this issue up for discussion with the team.

[TorsteinHonsi]

Simplified demo: https://jsfiddle.net/highcharts/j1sf2bpt/

Disabling the data labels makes the chart render fast.

[TorsteinHonsi]

Internal note

The root problem is that when getExtremesFromAll is true, the Series.getProcessedData produces processed data of the full length. Subsequently generatePoints creates Point instances for it all, and drawPoints and drawDataLabels follow up with DOM nodes.

Markers of a line chart are an exception to this, because they run Point.isInside before the marker is generated. But that's also a waste of processing time.

[tanmayshah95]

Hello @TorsteinHonsi
Thanks for quick reply and fix.
Will check on my Side.