1114400 - allow a preffed on CSS property alias to set a preffed off property

Status: RESOLVED WONTFIX

(Core :: CSS Parsing and Computation, defect)

Description

[Cameron McCormack (:heycam)]

In bug 649142 I want to put the margin-inline-start etc. logical properties behind a pref, and if the pref is not on, for the now-aliases -moz-margin-start etc. to keep working and be exposed using those old names on declarations.

Comment 1

[Cameron McCormack (:heycam)]

Attachment: patch

Comment 2

[David Baron :dbaron:]

Hmmm.  I have mixed feelings about this; I think the way that the property disables the alias was somewhat intentional, so that we wouldn't mess up disabling things.  Then again, we've since added the ability to have prefs for aliases, and it looks pretty ok given the current list of things in the aliases file, so I'm probably ok with the idea.

Comment 3

[David Baron :dbaron:]

That said, this still seems like a bunch of additional complexity that we don't need.

Why not just have which is the main property and which is the alias be the other way around until we're ready to enable the new ones?

Comment 4

[David Baron :dbaron:]

(Also, if we were to take this, I think I'd make you switch from three-booleans-in-sequence to a flags parameter.)

Comment 5

[Cameron McCormack (:heycam)]

(In reply to David Baron [:dbaron] (UTC-5) (needinfo? for questions) from comment #3)
> Why not just have which is the main property and which is the alias be the
> other way around until we're ready to enable the new ones?

I think this would cause declarations to appear to have -moz-* properties rather than the new properties, when the pref is enabled.  Unless we still add some functionality from this patch that maps the names that are exposed.  Still, that might be a smaller patch than the one I've attached, so let me try that and see.

Comment 6

[David Baron :dbaron:]

We can just switch the aliases to go the other way round when we enable the pref.  Shouldn't that be good enough?

Comment 7

[Cameron McCormack (:heycam)]

How can we turn one property into an alias and the other into a regular longhand at run time?  That sounds awfully complicated.

Comment 8

[David Baron :dbaron:]

No, I mean we'll land a patch around the same time we flip the pref.

Comment 9

[Cameron McCormack (:heycam)]

I guess we can do that.  But it means things will be broken for people testing with the pref on, or if we want to use #ifdef RELEASE_BUILD around the pref.

Comment 10

[David Baron :dbaron:]

We could also turn the new logical properties on (at least for horizontal) prior to turning vertical text on.

Comment 11

[Cameron McCormack (:heycam)]

OK, I'm just going to do comment 3.