Make WordPress Core

Opened 19 months ago

Last modified 4 weeks ago

#44471 new defect (bug)

Theme Editor: Modern CSS is marked as errors by CodeMirror

Reported by: ThemeZee Owned by:
Milestone: 5.4 Priority: normal
Severity: normal Version: 4.9
Component: Editor Keywords: needs-patch good-first-bug
Focuses: Cc:
PR Number:


I got some reports from users of my newest theme Donovan saying the style.css is broken.

The reason is that the code editor on Appearance > Theme Editor does not know modern CSS.

The CodeMirror plugin does not recognize CSS variables, new properties like grid-gap or the new fr units (fractions for CSS grids).

Attachments (1)

theme-editor-errors.png (80.8 KB) - added by ThemeZee 19 months ago.

Download all attachments as: .zip

Change History (15)

#1 @johnbillion
19 months ago

  • Keywords 2nd-opinion added
  • Version changed from 4.9.6 to 4.9

I feel like this is something that Codemirror will forever be playing catch-up with, especially given the pace of CSS development at the moment.

I wonder whether it's better for the CSS property validation to be disabled?

#2 @ianbelanger
19 months ago

I think that since the Theme Editor is something that end-users can access, the CSS property validation should probably be disabled by default. The majority of users will not understand that these type of "errors", are not really errors. End-users seeing these unnecessary error notices could lead to them doubting themes, plugins an their developers. IMHO

#3 @ThemeZee
19 months ago

Yes, it is hard to explain to end users that the theme is working fine although WordPress Core shows a bunch of error notices. The majority of users thinks these are major theme issues, because updating the style.css is basically deactivated unless the extra checkbox is clicked.

Disabling the CSS property validation would be great, although I'm not sure if it works everywhere. The CSS variables cause an "Expected RBRACE" error. This could perhaps be a syntax validation issue, because CodeMirror doesn't know how to handle the two hyphens at the beginning.

#4 @swissspidy
12 months ago

#45971 was marked as a duplicate.

#5 @joyously
10 months ago

#43840 was marked as a duplicate.

This ticket was mentioned in Slack in #core by joyously. View the logs.

10 months ago

#7 @ZanderZ
10 months ago

This is also a problem in the Customizer, when changing the Extra CSS. grid-template-columns: 1fr; is not recognised.

#8 @starvoters1
8 months ago

Is this the place to report that the CSS font-display, descriptor for @font-face is listed as an unknown property on Wordpress version 5.2.1?



#9 @pento
6 months ago

#47727 was marked as a duplicate.

#10 @studiotwee
4 months ago

so will this be fixed? having to constantly tell my editor that this CSS is perfectly fine is kinda driving me nuts.

#11 @ZanderZ
3 months ago

I'm guessing this won't be fixed in 5.3? :(

#12 @raoulunger
2 months ago

I second that. I write plenty of code for CSS grid, and none of it is recognized by the editor. I keep having to convince it (after every edit) that they are not mistakes. I understand that CSS evolves, and that the editor will lag behind somewhat for that reason. But CSS grid has been around for quite some time now and is fully accepted by all browsers (except IE), and you would think expanding the list with allowed code should not be too difficult. We had an update of WP last week, but again no changes in this respect...

#13 @SergeyBiryukov
5 weeks ago

#49001 was marked as a duplicate.

#14 @SergeyBiryukov
4 weeks ago

  • Keywords needs-patch good-first-bug added; 2nd-opinion removed
  • Milestone changed from Awaiting Review to 5.4

As #49062 shows, the CSS linting is not very reliable, displaying an error for Twenty Twenty default stylesheet with no particular error message.

Let's disable the linting be default, and perhaps make it a configurable setting that plugin authors could enable.

Last edited 4 weeks ago by SergeyBiryukov (previous) (diff)
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