Charts 2.0: Labels.formatter function is broken

[vaadin-bot]

Originally by HermanBovens

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I tried for several chart types including Heatmap to set my own custom formatting functions, and it doesn't work.

Even what is documented as the "default function" doesn't work:

   labels.setFormatter("function(){ return this.value; }");

fails because this.value is undefined.

I also tried defining my own custom function in a separated javascript file (loaded with @JavaScript), added as a property on window, but that property also turned out to be undefined inside the label's formatter function. I did check with the console in chrome and it was really defined on the window object.

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Imported from https://dev.vaadin.com/ issue #16197

[vaadin-bot]

Originally by Mingjie

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During my test, the same code works in column chart but broken in bar chart.