Sorting the CSS-Cascade-6 keys

[mirisuzanne]

While revert-layer is a new global value for explicit defaulting (like initial, etc) - it's generally considered part of the Cascade Layers feature.

Those other keys here are a problem. 😅 There are several names we would use for them in spec circles…

• What they are: the 'global keywords' or 'global values'
• What they do: 'explicit defaulting'

There are a number of resources that list them without any name, or only refer to them individually (including CanIUse), and a couple that refer to them as part of 'inheritance' (which is pretty vague). MDN has them separate but cross-referenced, and then also listed as values for the all property. CanIUse also shows the BCD keys individually, but each named global keywords: (keyword).

Since they are the only values allowed on all CSS properties, they are also the only values allowed on all. The all property is useless without these values - but they are very useful without all.

(side note: several of the top articles describe the feature wrong)

I find 'explicit defaulting' to be the most useful term here, for both the values and the all shorthand. But it also feels the most technical, and I can't argue that it's a popular term (I guess I have a new mission). I think the most accurate reflection of developer language is likely to list them as separate features.

We could consider adding them to a group (named what?) for better cross-reference.

[jamesnw]

I think the feature composition makes sense. I made a few suggestions for description length, and also to favor the The <property> <sets> the <noun> format that moves the most important parts to the front.

[ddbeck]

I like this. I have some suggestions for consistency in descriptions or to satisfy the test scripts. The only other thought I have here is that "explicit defaulting" is a really helpful lens. I don't think we can get away with defining a feature with that name (or at least not yet), but I think a group for explicit defaulting makes a ton of sense, if you'd like to put all of these in such a group.

[mirisuzanne]

@jamesnw @ddbeck thanks for the feedback! I think I've incorporated your notes, and added the explicit-defaults group, but check my work.

Ideally, revert-layer is both part of the Cascade Layers feature, and also the explicit-defaults group. But I don't think that's possible, unless we put all of Cascade Layers into that group? We could call it 'explicit cascading' instead…

[jamesnw]

Ideally, revert-layer is both part of the Cascade Layers feature, and also the explicit-defaults group. But I don't think that's possible, unless we put all of Cascade Layers into that group? We could call it 'explicit cascading' instead…

Features can't be part of another feature, but we could add a Cascade Layers group, and then explicit defaults could either be a child of that larger group, or revert-value could be in both groups.

[ddbeck]

@jamesnw's suggestion is the only way we could handle that now. We need to resolve #1173 to be able to put the key in multiple features (or at a higher level, have composite features that can be made up smaller atoms, see #971).

I think this looks good for now, but it would be nice to leave a comment on the cascade layers file, mentioning the possibility of doing that later?

[mirisuzanne]

@ddbeck looks like it needs to be re-approved with that change.

[ddbeck]

We're so close now. Prettier needs to be run on this and then we can merge.

[jamesnw]

We're so close now. Prettier needs to be run on this and then we can merge.

@ddbeck Done!