[Feature] How to get the axis range when datazoom scales it?

[masq6r]

What problem does this feature solve?

Hopefully the axis range could be known when it's changed.
I have y-axis scale set to true, and enabled datazoom. When I zoom or pan the chart, clearly the y-axis's range changes too. Now I need to know the new range.
I tried to listen to datazoom event but it doesn't look like any properties in the option could give me the values.

chart.on("datazoom", params => console.log(chart.getOption().yAxis[0]))

From the output I cannot see any information showing the y-axis range. Is there a way I can get it?

What does the proposed API look like?

Add a range property in the yAxis option:

yAxis: {
    range: [currentMin: number, currentMax: number]
}

[plainheart]

Maybe related to #17278

[masq6r]

Maybe related to #17278

Not really. I believe that the PR you quoted is about to access the data window's start-end index. In my case when I move the chart, x-axis range is changing and y-axis range is scaling to reflect that change, I'd like to know what that scaled y-axis range is.

[plainheart]

All right. I'm sorry I misunderstood. For now, we can only get it like this, which is not a public method.

const yAxisExtent = myChart
    .getModel()
    // get the first y-axis
    .getComponent('yAxis', 0)
    // get scale
    .axis.scale.getExtent();

See also this demo.

[masq6r]

All right. I'm sorry I misunderstood. For now, we can only get it like this, which is not a public method.

Thank you for your demo and the solution works. But since it's not public I cannot expect stability in future releases, can I? Anyway I'm closing the issue at the moment.

[plainheart]

But since it's not public I cannot expect stability in future releases, can I?

It's generally okay to use this non-public API. It's just not ready to expose to the users.

[bbcfive]

hi @plainheart, but how can I solve the ts error?

Property 'getModel' is private and only accessible within class 'ECharts'.ts(2341)

[plainheart]

@bbcfive This API is not exposed, so you have to use as any or // @ts-ignore to disable the TS check.