`tagName` should not be part of the manifest

[andyearnshaw]

`tagName` should not be part of the manifest

[thepassle]

I understood your point, but my point still stands. You can globally register custom elements in the browser, and in many cases this is not actually a problem. There are indeed cases where you'd need something like scoped elements. If you register a custom element in the global registry, you can use it via that tagName in your HTML, and a browser will know what to do with that element, so it still makes sense to support tagName in the manifest regardless of your opinion of it being a good or bad practice.

[thepassle]

I dont think this is controversial at all, but browsers do support registering custom elements on the global registry however, so I think it makes sense that the manifest supports tagName.

[andyearnshaw]

@thepassle I'm not sure if you understood my post. I guess the gist of it is that having tagName in the manifest (and the example in the README) promotes bad practice. Browsers support registering on the global registry, but any library or package exporting a custom element should not be doing that registration, it should be up to the consumer. Therefore, the tagName should not be in the manifest because it should not be decided what the tagName is by the library or package exporting it.

[justinfagnani]

To reenforce @thepassle's take here - the CEM is trying to describe what packages of elements can do, not prescribe what they should do. If there are elements out that the use global registration, this format should have the structure to say so.

That could enable tools that detect tag name collisions, or disallow using the global registry altogether, if that's your goal.