-webkit-line-clamp

[karlcow]

See https://bugzilla.mozilla.org/show_bug.cgi?id=866102

Gecko sometimes receives for the mobile version of Web sites, the -webkit-line-clamp feature which is not supported in Gecko at least.

Usage on the Web by Microsoft
https://developer.microsoft.com/en-us/microsoft-edge/platform/usage/css/-webkit-line-clamp/
This is used by big properties.

At the time of this issue creation:

Used on 0.979% of scanned pages, or 2,354,088 unique URLs

No documentation found on webkit blog.
https://www.google.com/search?q=webkit-line-clamp+site:webkit.org/blog

I didn't find the source in WebKit, but in blink
https://cs.chromium.org/chromium/src/third_party/WebKit/Source/core/style/ComputedStyle.h?type=cs&q=LineClamp+package:%5Echromium$&l=1678

https://cs.chromium.org/chromium/src/third_party/WebKit/Source/core/style/LineClampValue.h

[RByers]

Filed chromium bug to track getting help from the right chromium engineers on specifying our (and presumably WebKit's) behavior.

[miketaylr]

https://twitter.com/MSEdgeDev/status/969618335762612225

Wonder if anyone from the edge team wants to help spec? :) @patrickkettner, do you know who worked on it?

[miketaylr]

Oh, twitter tells me it was @cssrossen (maybe?). @cssrossen, want to collaborate on speccing out -webkit-line-clamp here in the compat standard? (edit: oh, that's not a github user ;---;)

[atanassov]

@miketaylr no promises on timeliness but certainly a reasonable thing to do.

[miketaylr]

Ah cool, this is getting taken care of https://drafts.csswg.org/css-overflow-3/#line-clamp

(cf. w3c/csswg-drafts#390 (comment)).

Let's close this issue since the -webkit-line-clamp alias will be specced by CSS Overflow.

[SelenIT]

It seems that the standardization of unprefixed line-clamp will take some time, there are open issues and "at risk" longhand parts of it currently. In the same time, the prefixed version is supported nearly everywhere. Doesn't it make sense to reopen this issue and reconsider including it into Compat Standard temporarily?

[miketaylr]

I'm not opposed to including the current behavior of -webkit-line-clamp, but don't really have the bandwidth to do this. If someone would like to submit a PR, I have no objections to re-opening (with an eye on removing it once all the issues are solved in CSS overflow).