293821 - Custom CSS properties not retrievable by getComputedStyle getPropertyCSSValue getPropertyValue

Status: RESOLVED DUPLICATE of bug 188321

(Core :: DOM: CSS Object Model, defect)

Description

[Ed Anuff]

User-Agent:       Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8b2) Gecko/20050504 Firefox/1.0+
Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8b2) Gecko/20050504 Firefox/1.0+

Custom properties specified in a style declaration are not retrievable via
script calls to document.defaultView.getComputedStyle().

Reproducible: Always

Steps to Reproduce:
Define a custom style:

.mybutton {
  -me-my-prop: true;
}

Try to retrieve it from an element it's been applied to:

var my_prop = document.defaultView.getComputedStyle(my_elem,
"").getPropertyValue("-me-my-prop");


Actual Results:  
no value retrieved

Expected Results:  
the value should have been retrieved

While the CSS spec says that the user agent can ignore property indentifiers
that it does not understand, with XBL, Mozilla should not assume that a property
not in it's internal list of supported properties might not be used by an XBL
binding.  Properties that follow the vendor extension syntax
(http://www.w3.org/TR/CSS21/syndata.html#q4) should at least be preserved and
retrievable by scripts.

Comment 1

[Anne (:annevk)]

Next time use search. "custom CSS" would have located the bug this is a
duplicate of. Thanks.

*** This bug has been marked as a duplicate of 188321 ***