[whatwg] Color attributes
zcorpan at gmail.com
Thu Aug 23 10:18:41 PDT 2007
On Fri, 27 Jul 2007 13:07:26 +0200, Simon Pieters <zcorpan at gmail.com>
> On Thu, 05 Jul 2007 23:43:55 +0200, Simon Pieters <zcorpan at gmail.com>
>> Color attributes in HTML have special processing.
>> Some tests/demos:
>> https://bugzilla.mozilla.org/attachment.cgi?id=188040 contains further
>> tests and an algorithm that is supposed to match what IE does. The only
>> flaw in that algorithm AFAICT is that there is a step missing before the
>> first step: match the value against the list of supported color
>> For reference, the complete algorithm would be:
>> 1. If the value case-insensitively matches a color keyword, use
>> that and
>> abort these steps. [CSS3COLOR]
> "transparent" is also to be treated as a keyword, meaning transparent.
> (It seems that IE treats transparent as black for text color, but that's
> a CSS thing.)
>> 2. Trim all but the first 128 chars from the string.
>> 3. If it exists, strip the first leading #.
>> 4. Replace non-valid-hex chars with 0s.
>> 5. Lower-case the string.
>> 6. Make string length a multiple of 3 and a minimum of 3 by
>> appending 0s.
>> 7. Split the string into 3 equal segments.
>> 8. Trim all but the right-most 8 chars from each segment.
>> 9. If segment length is 1, left-pad each segment with a 0, else:
>> 10. While segment length is greater than 2 and the first char of each
>> segment is equal to 0, trim the left-most char from each segment,
>> 11. Trim all but the first 2 chars from each segment.
>> 12. Join the segments and append them to a # char to create the final
Test cases for the algorithm:
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