911906 - Add an API for getting the authored value of a CSS property

Status: RESOLVED DUPLICATE of bug 731271

(Core :: CSS Parsing and Computation, defect)

Description

[Sebastian Zartner [:sebo]]

The Firebug Working Group wants to allow users to see the original values of their CSS properties.[1]

We're currently trying to get this info via inIDOMUtils.getRuleLine() and inIDOMUtils.getRuleColumn() from a cached version of the originally requested CSS.
Though this has several downsides:
1. We still have to parse the cached text by our own to get the properties, which isn't trivial and pretty error-prone.
2. Having to do a lot of extra steps to get the authored value is slow.
3. Extra work needs to be done to get the original values coming from other sources than CSS requested via the network, e.g. set via '<element>.style.<property>'.

So there should be an API introduced that allows to get the authored value of a CSS property.

Test cases:
CSS defined within a file:
See the test case of the Firebug issue[1].

CSS defined via appending a <style> tag:
1. Open the Web Console (Ctrl+Shift+K) on this page
2. Type the following into the command line and hit Enter:

style = document.createElement("style")
style.type = "text/css"
style.textContent = "#short_desc_nonedit_display { color: #f00; }";
document.body.appendChild(style)

3. Call the (not yet existing) API

=> The API should return '#f00'.

CSS defined via .style:
1. Open the Web Console (Ctrl+Shift+K) on this page
2. Type "document.getElementById('short_desc_nonedit_display').style.color = '#00f'" (without outer quotes) into the command line and hit Enter
3. Call the (not yet existing) API

=> The API should return '#00f'.

Sebastian

[1] http://code.google.com/p/fbug/issues/detail?id=5507

Comment 1

[Boris Zbarsky [:bzbarsky]]

Hww is this different from bug 731271?

Comment 2

[Cameron McCormack (:heycam)]

Sounds like it's not.  I should get back to that bug soon...

Comment 3

[Sebastian Zartner [:sebo]]

Yes, it's a duplicate of bug 731271. I obviously didn't find that one, because I was searching for "api" as keyword.

Sebastian