Less Parser support for @property (and other modern features)

[Stefanowitsch]

Hello @ryan

I just updated the UiKit Library to Version 3.24.0.

There have been minor changes in the LESS files of UiKit to make use of newer features (for example the @property rule). But that results in an error when trying to compile those files. For example:

It seems that the ProcessWire Less module is a bit outdated (or lets say: the wikimedia less parser that is used under the hood).

I downloaded the latest wikimedia less parser version and replaced it with the version used in the ProcessWire LESS module which solved some of the errors but not all. For Example the ":is" CSS selector throws an error too (when used inside a LESS file). 

So I guess just updating the wikimedia less parser does not work 😞

 

[dynweb]

I just tried to compile the SCSS version via CodeKit with Dart Sass 1.90.0 (a recent version) and got this:

Dart Sass failed with this error: expected ":".
    ╷
137 │ $property --uk-overflow-fade-start-opacity {
    │           ^
    ╵
  _uikit-3.24.0/components/utility.scss 137:11  @import
  _uikit-3.24.0/components/_import.scss 86:9    @import
  _uikit-3.24.0/uikit-theme.scss 6:9            @import

This should probably be @property?

Guess we have to wait for a UIKit update... This has been fixed in UIkit 3.24.1

[spoetnik]

I made a pull request to the ProcessWire Less parser to update it to the latest version of the wikimedia Less Parser. @ryan this pull request is still open.

https://github.com/ryancramerdesign/Less/pull/6

[bernhard]

@spoetnik does the latest version of the less parser fix all issues and make it work with the latest version of UIkit?

[spoetnik]

Yes, there is one minor issue :: https://github.com/wikimedia/less.php/issues/131

But it works with the latest version of UIkit!

[Stefanowitsch]

 

On 10/5/2025 at 8:09 PM, spoetnik said:

Yes, there is one minor issue :: https://github.com/wikimedia/less.php/issues/131

But it works with the latest version of UIkit!

There has been an update to the ProcessWire LESS Module to make use of the latest version from wikimedia. You have to set it in the module settings:

However this does not fix the error with the CSS ":is" selector in the latest UiKit version:

But that is not the only error that is popping up. After commenting out this piece of code there are other errors and more errors.

Again I think there is a conflict between the newest UiKit and the current Wikimedia LESS version. I will try to compile the UiKit less partials with a different compiler to see that happens there.

So my personal advice would be to stick to a UiKit version < 3.24.0 for now.

 

 

[spoetnik]

Oeps, I just checked the version of UiKit I'm using, and its 3.23.11... Sorry,

I wil try to update, and see if I can reproduce the error.