Intent to Implement and Ship: CSS flow-relative margins, paddings and borders

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Oriol Brufau

Jun 6, 2018, 9:38:20 AM6/6/18
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Implement the flow-relative margin, padding and border longhand properties introduced by CSS Logical Properties.
They are already supported but using non-standard names with a -webkit- prefix.
The properties with the standard names would be implemented, and the prefixed ones would become aliases.

Provide the author with the ability to control layout through logical, rather than physical, direction and dimension mappings.

On top of that, this will make it easier to share tests with Firefox in the implementation of new specifications.
For example, Firefox uses these properties extensively to test CSS Grid Layout, it'd be nice to have them available in Chromium to verify interoperability.

Interoperability risk
Firefox: Shipped.
Edge: Under Consideration, High Roadmap Priority
Safari: No public signals
Web developers: Some people are using PostCSS (there are few plugins there) to use these properties already due to lack of browsers support.

Tests for these new properties were added into the WPT suite in 

Compatibility risk
The existing prefixed properties will continue working as aliases, so the risk is minimal.
However, they will now serialize like the new properties.

Ongoing technical constraints

Will this feature be supported on all six Blink platforms (Windows, Mac, Linux,
Chrome OS, Android, and Android WebView)? 

OWP launch tracking bug

Link to entry on the Chrome Platform Status

Requesting approval to ship?

Rick Byers

Jun 6, 2018, 12:59:11 PM6/6/18
to, blink-dev
There's an earlier intent here for a superset of this work which already has an LGTM1 from foolip, so I assume (unless he says otherwise) that still applies.

Unprefixing these LGTM2, thank you!

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Yoav Weiss

Jun 6, 2018, 1:11:37 PM6/6/18
to Rick Byers,, blink-dev

Can you also add use-counters (if there aren't already) to the prefixed version do that we'll have data on their usage and maybe one day be able to remove them?

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Rick Byers

Jun 6, 2018, 2:04:01 PM6/6/18
to Yoav Weiss,, blink-dev
Good idea!  In general all of our prefixed APIs should either be on a path to removal, or something we should spec as part of the web platform (worst case, in the compat spec if the spec for the unprefixed versions isn't interested in documenting reality).

Oriol Brufau

Jun 6, 2018, 4:21:41 PM6/6/18
to Yoav Weiss, Rick Byers, blink-dev

Yes, there are counters for the prefixed properties already, and there will be counters for the new properties too.

Once the standard properties are shipped, we can send an intent to deprecate or remove the prefixed ones, whichever is appropriate.

-- Oriol Brufau

El 6/6/18 a les 19:11, Yoav Weiss ha escrit:
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