Events API

[goatandsheep]

Is there a way to show events fired?

[aeschli]

What kind of events?

[goatandsheep]

@aeschli sorry for my lack of clarity. I mean for events fired by the elements, particularly custom elements

[aeschli]

Please give some examples... Maybe a small sample code what you expect to see (hovers, code completion...)

[goatandsheep]

I think that @event is a great example for how it could be denoted. The hover for jsdoc is really good. I think the hover could either:

• simply have the event in the description of the element
• treat it like an attribute with the name on<custom-event-name>

[aeschli]

I guess this is about JavaScript/TypeScript then. Still I don't know what exactly you suggest to improve or add. Something for VSCode to show, or a TypeScript language feature?

[goatandsheep]

Similar to this issue WICG/webcomponents#776 that addresses displaying details about custom components, I would add to it to show events when writing HTML

[octref]

If all you want is onMyEvent as an attribute completion, why can't you use the existing globalAttributes? https://github.com/Microsoft/vscode-html-languageservice/blob/master/docs/customData.md

[goatandsheep]

@octref because the type of input is always function, but what's important about documenting events is not the type of input but the type of data from the event

[octref]

We don't do any type-checking diagnostic for HTML attribute value, at least not on the HTML service.

What Language Feature exactly do you want for events?

[aeschli]

ping @goatandsheep
Please explain how support for events would look like in the UI.
Maybe a small sample code along with what you expect to see (hovers, code completion...)

[goatandsheep]

@aeschli I was thinking about how when you do event handling in the HTML, your input for an oncustombind would be a callback function, so the documentation for an event should be like any other Javascript function, i.e. JsDoc. However, as @octref mentioned, that would be checked in Javascript, not HTML, anyways. So it would likely be enough to simply add onevent with a description of the event and the type being Function.

It's fine if referring to events in the hovers doesn't require code changes, but we should encourage use and show examples of how it would be used.

[octref]

Due to the myriad ways people load their JS it's impossible to check where the value of myevent="something" comes from. I don't want Schrodinger's diagnostics for myevent="window.foo", so no.

[goatandsheep]

@octref would this standard for documenting custom elements using jsdocs by @runem still require a myriad of ways to diagnose the values?

[octref]

You should ask them to generate data of this format: https://github.com/microsoft/vscode-html-languageservice/blob/master/docs/customData.md.

[goatandsheep]

@octref thank you for the suggestion! They actually already do generate data of that format, but the format is quite rudimentary as it doesn't let you list events, slots, nor cssprops. I'm thinking, instead of trying to interpret each of the jsdoc tags and every future request that may come, is there a way to just show various tags as hover comments?

[octref]

No. Each item's description is shown on hover. That's all. Ask them to put whatever they want into the description.

[goatandsheep]

That's perfect. Thanks @octref !