I've read the docs regarding typescript on Highcharts but I still don't have it very clear how to use types in highcharts.js functions.
For example, I have a formatter function on my tooltip options and it admits a parameter this. How do I type it?
Right now I'm using any but that's just to bypass the typescript errors. I don't want to manually type it in case Highcharts updates its content in future versions, so I assume there's a proper way of doing it?
const options = {
tooltip: {
outside: true,
formatter: function (this: any): string { // <---- need to replace `any` here
}
}
}
What type should I use there? And how do I find out exactly which of them should I use?
I've tried using Highcharts.TooltipFormatterCallbackFunction as that's what seems to be indicated in the callback docs.
formatter: function (this: Highcharts.TooltipFormatterCallbackFunction): string {
But it doesn't seem to recognize the property y inside the this object. this.y.
Perhaps that's the return type? Where do I look for the one for this?
Same problem with plotOptions.column.point.events.mouseOver:
plotOptions: {
column: {
point: {
events: {
mouseOver: function (this: any) { //<-- here
this.graphic.attr({
fill: this.y < 0 ? "red" : "blue",
});
}
}
}
}
}
