Give elements their own interface definition

[joshkel]

From what I understand, if we want to allow registering additional element options (see here for an example), then the element options need to be a top-level interface so that they can be used with TypeScript's declaration merging.

[simonbrunel]

When I read ElementOptions, I'm thinking of options for an element, and I would expect to be able to extend it for each element type (i.e. interface ArcOptions extends ElementOptions). Shouldn't this be named differently then, maybe ElementsOptions or ElementOptionsMap or something else that makes it clear it's a record of element type -> element options (ElementOptionsByType)?

[joshkel]

Thanks for the feedback.

I see your point. For what it's worth, the name ElementOptions would match the current PluginOptions (which seems to serve a similar purpose). Otherwise, I might pick ElementOptionsMap (seems clearest to my personal taste) or ElementsOptions (to be a bit more consistent with pre-existing type definitions' names).

I don't have a strong opinion, so I'll defer to others.

After taking another look at this, I realized that I could probably set up a ...Registry interface; this should serve the same purpose and would be similar to Chart.js's ScaleTypeRegistry and ChartTypeRegistry.

export interface ElementTypeRegistry {
        arc: ArcOptions & ArcHoverOptions;
        bar: BarOptions & BarHoverOptions;
        line: LineOptions & LineHoverOptions;
        point: PointOptions & PointHoverOptions;
 }
 export interface ElementChartOptions {
       elements: { [k in keyof ElementTypeRegistry]: ElementTypeRegistry[k]; };
 }

Or, using an options sub-object to match the other ...TypeRegistries: (This doesn't seem to be necessary for elements, but it's consistent and allows room for future growth.)

export interface ElementTypeRegistry {
	arc: {
		options: ArcOptions & ArcHoverOptions;
	}
	bar: {
		options: BarOptions & BarHoverOptions;
	}
	line: {
		options: LineOptions & LineHoverOptions;
	}
	point: {
		options: PointOptions & PointHoverOptions;
	}
}
export interface ElementChartOptions {
	elements: { [k in keyof ElementTypeRegistry]: ElementTypeRegistry[k]['options']; };
}

Thoughts?

[simonbrunel]

I agree, same problem with PluginOptions, ScaleOptions (and maybe some others). For this last, it's even more confusing because there is CoreScaleOptions. There is also CommonOptions which is too generic ("common" for what?) and should be renamed since it's not an interface that's supposed to be extend by all options set.

I would reserve these {Type}Options (i.e. PluginOptions, ScaleOptions, ElementOptions, etc.) for base interfaces, containing common properties for each type (if needed). We could prefix them to make explicit that these are "base" interfaces but I'm not sure I would pick Core (maybe Base instead).

I'm not convinced by ElementOptionsMap finally because it's not a JavaScript Map, so could be confusing. I'm not familiar with these *Registry types, but if it's a common pattern in our TD, then I guess it's a good one. Though, it would need to contain Options in the name (maybe ElementOptionsRegistry) because we can also have a registry for element (not element options). Then we should also rename PluginOptionsRegistry, ScaleOptionsRegistry, etc.

I kind like/prefer my last suggestion: ElementOptionsByType (PluginOptionsByType, ScaleOptionsByType) because it's clear that's a plain object containing a mapping between the type name and options. With Registry, it's a bit confusing because I understand "registry" as an object containing some logic / extra methods (i.e. ScaleOptionsRegistry.register()).

Finally, I would rename ElementChartOptions as well (or even better, remove it since I find it useless and making hard to understand the type hierarchy.

[kurkle]

I'd prefer ElementTypeOptions over ElementOptionsByType. Not a strong opinion, just personal preference on naming conventions.

[kurkle]

Should the naming changes be done in a separate commit? This is getting stale.

[etimberg]

I can followup with the naming changes if we want to merge this @kurkle.

[kurkle]

I can followup with the naming changes if we want to merge this @kurkle.

Works for me