[whatwg] Accept full CSS colors in the legacy color parsing algorithm
ian at hixie.ch
Fri Jul 15 11:43:25 PDT 2011
On Fri, 8 Apr 2011, Tab Atkins Jr. wrote:
> In the legacy color parsing algorithm
> steps 5 and 6 concern CSS color names - 'transparent' should raise an
> error, and color names should be respected. All other CSS color
> syntaxes, though, such as the rgba() function, are just passed through
> to the rest of the algorithm and appropriately mangled.
> This doesn't match Webkit's behavior. Instead of steps 5 and 6, we just
> try to parse it as a CSS color. If we succeed, we use that color.
> Otherwise, we chunk it into the legacy parsing algorithm and do what the
> spec says. So, for example, <font color=rgba(255,0,0,.5)>foo</font> is
> actually displayed as partially-transparent red instead of dark green
> (following the algorithm mangles the string into #050).
> Could we change those two steps to just say "If keyword is a valid CSS
> color value, then return the simple color corresponding to that value."?
> (I guess, to fully match Webkit, you need to change the definition of
> "simple color" to take alpha into account.)
On Fri, 8 Apr 2011, Boris Zbarsky wrote:
> But it does match other UAs....
> Do you have web compat data here?
> I would much rather stick with color parsing as defined in HTML4 modulo
> the "not a color name, treat it as a hex color even if it doesn't start
> with '#'" quirk than replace the "is it a color name?" test with a "does
> it parse as a CSS color?" test.
On Wed, 13 Apr 2011, Philip Taylor wrote:
> I don't know if this is relevant or useful but anyway:
> http://philip.html5.org/data/font-colors.txt has some basic data for
> <font color> values, http://philip.html5.org/data/bgcolors.txt for <body
> bgcolor>. (Each line is the number of URLs that value was found on (from
> the set from http://philip.html5.org/data/dotbot-20090424.txt), followed
> by the XML-encoded value.)
Looks like there are values that would be affected by this change.
I've left it as-is. I think compat here is vastly more important than
adding new capabilities, since this is only used for legacy features.
Ian Hickson U+1047E )\._.,--....,'``. fL
http://ln.hixie.ch/ U+263A /, _.. \ _\ ;`._ ,.
Things that are impossible just take longer. `._.-(,_..'--(,_..'`-.;.'
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