1308636 - Remove support for -moz-prefixed CSS multi-column properties

Status: RESOLVED FIXED

(Core :: Layout: Columns, task, P3)

Description

[Neerja Pancholi[:neerja]]

This bug is part (5) from Bug 698783 comment#15

Comment 1

[Neerja Pancholi[:neerja]]

Aliases for these properties were previously introduced in Bug 1300895

Comment 2

[Ting-Yu Lin [:TYLin] (PST, UTC-8)]

According to dbaron's instruction in bug 698783 comment 12, I believe all the prerequisites to remove moz-prefixed multi-column properties (including column-gap defined in CSS alignment) have been done.

We've shipped all the multi-column properties (including column-span). The internal usages of the properties have been converted to standard ones in bug 1308587, although there are still some missed that I'll address in this bug.

Comment 3

[Ting-Yu Lin [:TYLin] (PST, UTC-8)]

Attachment: Bug 1308636 Part 2 - Convert CSSOM usages of moz-prefixed column properties in tests. r=dbaron

This patch was generated by the following shell script.

function remove_column_prefix() {
    echo "Renaming $1 to $2"
    find .\
         -type f\
         ! -path "./obj*"\
         ! -path "./.git"\
         ! -path "./.hg"\
         \( -name "*.html" -or\
            -name "*.xhtml" -or\
            -name "*.xht" -or\
            -name "*.xul" -or\
            -name "*.xml" -or\
            -name "*.svg"  \)\
            -exec sed -i -e "s/$1/$2/g" "{}" \;
}
remove_column_prefix "MozColumn" "column"

Depends on D59562

Comment 4

[Ting-Yu Lin [:TYLin] (PST, UTC-8)]

Attachment: Bug 1308636 Part 3 - Remove moz-prefixed aliases for column-gap and CSS multi-column properties. r=dbaron

The modification to properties-db.js was generated by
./mach devtools-css-db.

Depends on D59563

Comment 5

[Ting-Yu Lin [:TYLin] (PST, UTC-8)]

Attachment: Bug 1308636 Part 1 - Convert -moz-column-span to column-span in a crashtest. r=dbaron

-moz-column-span missed the conversion in Bug 1308587 Part 2.
https://hg.mozilla.org/mozilla-central/rev/bb59a0c37162

Comment 6

[Emilio Cobos Álvarez (:emilio)]

I'm a bit uneasy doing this. Like sure, it's easy, but aliases are cheap and there's background for some sites (mainly google properties) only sending us -moz- prefixed stuff.

Is there a benefit of removing the aliases from the engine?

Comment 7

[Mike Taylor [:miketaylr]]

I agree with emilio here. Can we at least stick it behind a pref that ships to pre-release for a few releases to get a sense of any potential fallout?

Comment 8

[Ting-Yu Lin [:TYLin] (PST, UTC-8)]

Is there a benefit of removing the aliases from the engine?

Since it is easy to remove the prefix, the implementation isn't simplified as much. However, I feel this is a question of doing now or never.

I agree with emilio here. Can we at least stick it behind a pref that ships to pre-release for a few releases to get a sense of any potential fallout?

I agree it's better to unprefix in pre-release for a few releases for any web-compat fallout. dbaron suggests this in the review as well
https://phabricator.services.mozilla.com/D59564#1816396

I think it's easy to switch the prefix behind a pref like
https://searchfox.org/mozilla-central/rev/d4d6f81e0ab479cde192453bae83d5e3edfb39d6/servo/components/style/properties/longhands/position.mako.rs#318

Comment 9

[Ting-Yu Lin [:TYLin] (PST, UTC-8)]

In the latest revision, I added a pref layout.css.prefixes.columns to guard the prefixed properties behind, and use false by default for all channels.

Comment 10

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/21f9476a9588
Part 1 - Convert -moz-column-span to column-span in a crashtest. r=dbaron
https://hg.mozilla.org/integration/autoland/rev/08e88920caa4
Part 2 - Convert CSSOM usages of moz-prefixed column properties in tests. r=dbaron
https://hg.mozilla.org/integration/autoland/rev/b7913d967261
Part 3 - Remove moz-prefixed aliases for column-gap and CSS multi-column properties. r=dbaron

Comment 11

[Kohei Yoshino]

Posted site compatibility note.

Comment 12

[Oana Pop-Rus]

https://hg.mozilla.org/mozilla-central/rev/21f9476a9588
https://hg.mozilla.org/mozilla-central/rev/08e88920caa4
https://hg.mozilla.org/mozilla-central/rev/b7913d967261

Comment 13

[Chris Mills [:cmills]]

Documentation complete, see https://github.com/mdn/sprints/issues/2739#issuecomment-583468459