Sebastian Zartner [:sebo] Assignee
	Description • 8 years ago

The CSS Values and Units Module Level 3 now defines[1] new types merging combinations of <percentage> with other types.
Specs containing such combinations are slowly adjusting their property and descriptor syntaxes.

To comply we need to adjust the syntaxes stored in the {{CSSData}} template.

The new types are:

<length-percentage> = [ <length> | <percentage> ]
<frequency-percentage> = [ <frequency> | <percentage> ]
<angle-percentage> = [ <angle> | <percentage> ]
<time-percentage> = [ <time> | <percentage> ]
<number-percentage> = [ <number> | <percentage> ]

Sebastian

[1] https://drafts.csswg.org/css-values-3/#typedef-length-percentage

	Sebastian Zartner [:sebo] Assignee
	Comment 1 • 8 years ago

The types were added to {{CSSData}}, usages still need to be adjusted.

Sebastian

	Sebastian Zartner [:sebo] Assignee
	Comment 2 • 8 years ago

Jean-Yves, should we add replace the separate types by the new combined ones even when the related specs are not adjusted yet?

Sebastian

	Jean-Yves Perrier [:teoli]
	Comment 3 • 8 years ago

I think we should do it at some point. I'm wondering if it is a bit too early: do you have some log/e-mail from the CSSWG explaining why they made this change and if there was unanimity or dissension there?

as it is a significant amount of work for MDN, I just want to be sure such change will stick before doing it.

	Sebastian Zartner [:sebo] Assignee
	Comment 4 • 8 years ago

(In reply to Jean-Yves Perrier [:teoli] from comment #3)
> I think we should do it at some point. I'm wondering if it is a bit too
> early: do you have some log/e-mail from the CSSWG explaining why they made
> this change and if there was unanimity or dissension there?

Yes, here it is:
https://lists.w3.org/Archives/Public/www-style/2015Dec/0150.html

Reasoning is to disambiguate how percentages resolve, especially in regard of Houdini.

> as it is a significant amount of work for MDN, I just want to be sure such
> change will stick before doing it.

Only fantasai expressed some concern (in the thread above) saying that the values other than <length-percentage> should not be added if they're not used, but since then I've already done those changes to several CSS specs[1] and others also picked the new values up[2]. So, I believe it's pretty safe to do this.
Also, the amount of work is relatively small, mostly search & replace.

Sebastian

[1] See e.g. https://github.com/w3c/csswg-drafts/pull/268 or https://github.com/w3c/csswg-drafts/pull/263
[2] https://github.com/w3c/svgwg/issues/190, https://github.com/w3c/csswg-drafts/issues/186

	Jean-Yves Perrier [:teoli]
	Comment 5 • 8 years ago

So let's go ahead.

	Sebastian Zartner [:sebo] Assignee
	Comment 6 • 8 years ago

I changed the syntaxes of the following items:

-webkit-mask-position-x
-webkit-mask-position-y
border-bottom-left-radius
border-bottom-right-radius
border-image-slice
border-image-width
border-top-left-radius
border-top-right-radius
font-size
grid-column-gap
grid-row-gap
motion-offset
perspective-origin
shape-margin
transform-origin

<bg-size>
<brightness()>
<color-stop>
<contrast()>
<fixed-breadth>
<grayscale()>
<invert()>
<mask-position>
<opacity()>
<position>
<saturate()>
<sepia()>
<size>
<track-breadth>
<translate()>
<translate3d()>
<translateX()>
<translateY()>
<viewport-length>

@viewport/max-zoom
@viewport/min-zoom
@viewport/zoom

I didn't change the value descriptions on the pages yet, i.e. they may still have separate descriptions.
I excluded all CSS 2.1 properties, which don't have a superseding spec. yet, as they likely won't change soon.

Jean-Yves, two questions. Should I also merge the value descriptions? And should I also adjust the syntaxes of CSS 2.1 properties?

Sebastian

	Jean-Yves Perrier [:teoli]
	Comment 7 • 8 years ago

We should do the value descriptions, and incoherence may be a bit weird.

For the CSS 2.1 properties, let's wait, I don't think there is any reason to be ahead of CSSWG there. I know of a CSS 2.2 coming at some point, and it may be interesting to check if they changed the syntax there (and eventually to propose that they do it, if they didn't).

	Sebastian Zartner [:sebo] Assignee
	Comment 8 • 8 years ago

(In reply to Jean-Yves Perrier [:teoli] from comment #7)
> We should do the value descriptions, and incoherence may be a bit weird.

Ok, will work on that.

> For the CSS 2.1 properties, let's wait, I don't think there is any reason to
> be ahead of CSSWG there. I know of a CSS 2.2 coming at some point, and it
> may be interesting to check if they changed the syntax there (and eventually
> to propose that they do it, if they didn't).

Filed https://github.com/w3c/csswg-drafts/issues/504 for that.

Sebastian

	Sebastian Zartner [:sebo] Assignee
	Comment 9 • 8 years ago

(In reply to Sebastian Zartner [:sebo] from comment #8)
> Filed https://github.com/w3c/csswg-drafts/issues/504 for that.

That issue only received a negative feedback by fantasai so far, so let's not change the related syntaxes for now.

I've updated the value descriptions on the pages to reflect the syntax changes and filed https://github.com/w3c/csswg-drafts/issues/646 covering the rest of the required spec. changes.

Sebastian