238758 - Missing CSS rule in DOM Inspector's Object CSS Style Rules

Status: VERIFIED DUPLICATE of bug 185431

(Other Applications :: DOM Inspector, defect)

Description

[Christophe Porteneuve]

User-Agent:       Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.6) Gecko/20040206 Firefox/0.8
Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.6) Gecko/20040206 Firefox/0.8

When specifying an attribute-based CSS rule, such as the commonplace:

a[hreflang]:after {
     color: gray;
     content: "\0000a0[" attr(hreflang) "]";
}

This rule does not show in the DOM Inspector's CSS Style Rules view for the DOM
nodes that use it. The rule *is* applied, but only other rules (e.g. "a",
"a:hover" and so forth) show in the node's rules view.

Reproducible: Always
Steps to Reproduce:
1. Create a Web page wtih a single paragraph that contains an anchor with a
hreflang attribute (e.g. set to "en") : <a href="..." hreflang="en"
title="demo">...</a>.
2. Create a stylesheet, either internal (<style>) or external (<style>/<link>),
with a rule such as the one described in Details.
3. Load the page in your Mozilla-based browser. Verify the rule is applied.
4. Fire up the DOM Inspector (Tools | DOM Inspector)
5. Expand the nodes until you can select your anchor.
6. In the right-hand part, select CSS Style Rules in the drop-down list next to
the "Object - DOM Node" heading.
7. Voila! No mention of your rule, despite its being applied.
Actual Results:  
The rule doesn't show!

Expected Results:  
The rule should show...

Comment 1

[Rene Pronk]

Yeah, the rule should show up somewhere in the DOM Inspector. I'm not sure if
the CSS Style Rules is the best place (Computed Style is where I would look
first I guess) but it should show up somewhere.

Comment 2

[Christophe Porteneuve]

Well, it makes perfect sense to have it show up in CSS Style Rules. Computed
styles is for cascaded/default effects. When a rule does specifically address
the node, it shows up in CSS Style Rules.

The rule above does specifically address the A node.

Comment 3

[Christopher Aillon (sabbatical, not receiving bugmail)]

>The rule above does specifically address the A node.

No.  It addresses "A:after", which is generated content, not the "A" node you
are looking at....

Comment 4

[Christophe Porteneuve]

That's a good point, however :after is a pseudo-selector, and the only possible
nodes in the DOM tree it relates to are defined by the A tag. There's just no
other way to get to these through the DOM inspector, and since content is
(pre|ap)pended to the node's contents, it seems like the right place to display it.

Comment 5

[Christopher Aillon (sabbatical, not receiving bugmail)]

*** This bug has been marked as a duplicate of 185431 ***