Datalabel nodes with empty text is still rendered

[praneetloke]

Description

When datalabels are enabled it seems that even returning an empty string value or undefined from the formatter function renders empty <text> nodes which affects performance. It seems that we have to completely disable datalabels when there are quite a few data points. I only noticed this because I saw a console warning being printed about there being too many datalabels. Also it seems that I could get rid of the warning by simply setting the maxItems to equal the length of the data points in the series but I don't want to do that. I would not like the <text> nodes to render at all if the formatter returns undefined or empty string value (but ok to render if 0 is returned since it is a valid label value.) I would also be ok if it didn't render only if undefined is returned which is not the case as I tried that too.

Steps to Reproduce

1. Create a column chart (bar) with at least 200 data points
2. Enable data labels via dataLabels.enabled property
3. Warning is printed in the console

Expected Behavior

Empty text nodes are not rendered.

Actual Behavior

Empty text nodes are rendered.

Screenshots

N/A

Reproduction Link

https://codepen.io/praneetloke/pen/vYJqYdo

[junedchhipa]

Hey, even though I applied a fix for this issue in v3.31.0, it caused issues at other places.
Because those text nodes are required to know which was the last drawn data label, I have to draw empty labels. The best way would be to store the dimensions in a variable instead of depending on actual nodes. I will re-open this and find a better way to solve it.