Unable to set CSSStyleRule.style

Based on local testing, this works correctly on the element.style attribute – e.g. this works fine in Edge 15:
document.documentElement.style = “font-family: CCC”

So Edge has this implemented correctly for the ElementCSSInlineStyle interface. But not for the CSSStyleRule interface. (In WebKit/Safari10.1, it’s broken in both interfaces, actually – the above document.documentElement.style tweak is rejected there.)

Here’s the relevant part of the spec for the element.style attribute, I think:
https://drafts.csswg.org/cssom/#the-elementcssinlinestyle-interface

interface ElementCSSInlineStyle {
[SameObject, PutForwards=cssText] readonly attribute CSSStyleDeclaration style;
};

And for the CSSStyleRule.style attribute:
https://drafts.csswg.org/cssom/#the-cssstylerule-interface

interface CSSStyleRule : CSSRule {
attribute CSSOMString selectorText;
[SameObject, PutForwards=cssText] readonly attribute CSSStyleDeclaration style;
};

Notice that the WebIDL is the same for these two “style” attributes, so they should be equivalently assignable.

Hey Daniel :)

Thanks for reporting the issue.

It so happens I am the person who implemented the style setter on the Element interface one or two releases ago, not because it met our bug bar but because it annoyed me personnally.

At the point, I had considered also updating the CSS OM idls but ultimately decided not to, to keep my change as small as possible. I am not really supposed to write code ;-)

I’ll keep this on the backlog to track this work but I do not expect this to get fixed anytime soon, as it just doesn’t break much more than a few browser-implementor-written test cases.

Hi Francois! Thanks for

Hi Francois! Thanks for the prompt response.

You might be interested to know that the WebKit folks landed a fix for this yesterday (on https://bugs.webkit.org/show_bug.cgi?id=164537 ), so at this point Edge is the only browser engine affected by this bug.

Having said that, I share your feeling that this particular quirk (on the CSSStyleRule interface) isn’t likely to cause breakage in much real-world web content. So, backlog + fixed-eventually sounds OK.