Using the Chart Config Editor to customise tooltips for pie charts

[ruthc]

I am using the Chart Config Editor to customise tooltips for a pie chart. Currently, my tooltip includes the following information:

• a circle, which is rendered the same colour as the segment colour
• the value of the segment (e.g. 267,023)
• the percentage share of the segment (e.g. 32%)

tooltip: {
format: '<span style="color:{color}">\u25CF</span> {key}<br/>{y:,.0f} ({percentage:,.0f}%)',
},

I also want to include the name of the measure (e.g. 'Items Sold'). I don't want to hard-code this by just typing 'items sold' into the format property. For cartesian charts, I would just include the variable {series.name}. However, for pie charts, this variable generates the text 'Series 1' for every segment. How do I reference the series name for pie charts?

(In case this is helpful to anyone else, here are the variables that I have documented so far:)