1684605 - Implement @property at-rule

Status: RESOLVED DUPLICATE of bug 1273706

(Core :: CSS Parsing and Computation, enhancement)

Description

[Sebastian Zartner [:sebo]]

This bug is meant to track the implementation of the @property at-rule defined in the CSS Houdini Properties and Values specification which allows to define custom properties in CSS.

Sebastian

Comment 1

[mdihosseinzadeh]

This is a useful feature. See the Stack Overflow post: animating gradients in CSS for a use case.

Is there any estimate for when it will be implemented?

Comment 2

[mdihosseinzadeh]

The related bug in Webkit (Safari): https://bugs.webkit.org/show_bug.cgi?id=189692

Comment 3

[Emilio Cobos Álvarez [:emilio]]

No estimate right now, though patches welcome? https://github.com/emilio/css-typed-om-syntax has a parser for the typed-om syntax that could be used to prototype this.

Comment 4

[Simon Pieters [:zcorpan]]

@property was recently enabled in WebKit: https://bugs.webkit.org/show_bug.cgi?id=249774

Comment 5

[Daniel Holbert [:dholbert]]

Removing dev-doc-needed keyword since https://developer.mozilla.org/en-US/docs/Web/CSS/@property exists at this point. (Feel free to add back with details on what's needed if I'm missing something, though.)

Comment 6

[Sebastian Zartner [:sebo]]

Well, unless the MDN team works differently nowadays, dev-doc-needed indicates that the related browser compatibility data entry needs to be updated once this feature landed.
I also assume that this will initially be implemented behind a pref. In that case it should also be documented at https://developer.mozilla.org/en-US/docs/Mozilla/Firefox/Experimental_features. So I added the keyword back.
Once there's a bug to ship @property (maybe together with the DOM API), dev-doc-needed should also be added there in order to update the browser compat data and remove it from the experimental features page again once that bug is closed.

Sebastian

Comment 7

[parsimonhi]

I also think that this is a useful feature.

Parsimonhi

Comment 8

[Lojzo Alojz]

Why are you censoring parsimonhi's opinion? Man, BugZilla needs to change, because it is terrible, GitHub and GitLab are much better.

Comment 38

[Frédéric Wang Nélar]

Attachment: WIP: Bug 1684605 - Expose custom property registration per name.

Comment 39

[Frédéric Wang Nélar]

Basic support for @property has landed in bug 1840476 and we have recently used bug 1273706 as a meta to refine the implementation. So marking this as a duplicate of bug 1273706 (which also has the dev-doc-needed flag BTW).