What problem does this feature solve?
Many eChart's own types are not exported. For example DecalObject.
A lot of the useful types are not exported by eCharts. So one is either faced with a choice to have untyped objects in one's code or to find a way to get to the un-exported types using TypeScript's powerful type system. For example:
import * as echarts from 'echarts';
type EChartInitParams = Parameters<typeof echarts.init>;
// eCharts docs say `It's only optional when opts.ssr is enabled for server-side rendering.` about the `dom` parameter.
// However, the declared type of this parameter is not optional, so we fix it in our derived type.
type EChartInit = (
dom?: EChartInitParams[0],
theme?: EChartInitParams[1],
opts?: EChartInitParams[2]
) => ReturnType<typeof echarts.init>;
// This type is not exported, so we do a few tricks here to get it.
type EChartInitOptions = Exclude<EChartInitParams[2], undefined>;
export type ChartInitOptions = EChartInitOptions & {
height?: Exclude<EChartInitOptions['height'], string>;
width?: Exclude<EChartInitOptions['width'], string>;
};or more generally:
type ExportedOrNotWeCanGetToItAnyway_SoMightAsWellMakeItEasierForUs = echarts.ExportedType['propertyWithUnexportedType'];
Given that we mostly can gain access to un-exported types one way or another through exported ones, the whole point of not exporting types is a bit moot.
zrender types used by eCharts are not re-exported by eCharts
For example, we have to add a transient zrender dependency to our package.json and do something like the following to access to the type that is part of eChart's public interface but is not re-exported:
import * as zrender from 'zrender';
// then somewhere later in our code
highlight?: {
style?: zrender.PathStyleProps;
...
}What does the proposed API look like?
For eChart's own types:
import * as echarts from 'echarts';
// echarts.ChartInitOptions is exported, so deriving from it becomes a lot easier now
export type ChartInitOptions = echarts.ChartInitOptions & {
height?: Exclude<echarts.ChartInitOptions['height'], string>;
width?: Exclude<echarts.ChartInitOptions['width'], string>;
};For zrender types used by eCharts:
import * as echarts from 'echarts';
// No need to add zrender transient dependency to package.json and import types from there because zrender types used by echarts are re-exported by echarts.
highlight?: {
style?: echarts.PathStyleProps;
...
}
What problem does this feature solve?
Many eChart's own types are not exported. For example
DecalObject.A lot of the useful types are not exported by eCharts. So one is either faced with a choice to have untyped objects in one's code or to find a way to get to the un-exported types using TypeScript's powerful type system. For example:
or more generally:
Given that we mostly can gain access to un-exported types one way or another through exported ones, the whole point of not exporting types is a bit moot.
zrender types used by eCharts are not re-exported by eCharts
For example, we have to add a transient
zrenderdependency to ourpackage.jsonand do something like the following to access to the type that is part of eChart's public interface but is not re-exported:What does the proposed API look like?
For eChart's own types:
For zrender types used by eCharts: