[dev] CSS Parsing class

[Michael M Slusarz]

There's been talk on the mailing lists recently about the limitations  
of the current Horde_Text_Filter_Csstidy package (essentially a  
wrapper around the unmaintained PHP csstidy code).

By fortuitous chance, the same issue came up with one of my clients.   
Thus, plenty of impetus to look into replacing the library with a new  
library.

Turns out there is a stable, CSS3 compliant, stateful, object oriented  
PHP parser that exists and is favorably licensed (MIT/Expat license):
https://github.com/sabberworm/PHP-CSS-Parser

It turned out to be fairly easy to write a new Horde wrapper around  
this class (Horde_Css_Parser;  
https://github.com/horde/horde/commit/8fe7c6a52443ceab1a3c2a7e4b364f6ba005e059).  And the results seem to work beautifully.  Haven't played around much more than parsing the existing CSS code, but this code handles the issues requiring us to parse CSS in the first place: relative URL translation and @import  
replacement.

As such, there is no reason to delay making the change, especially  
considering the alternative (csstidy) is known to be broken in  
multiple respects.  This code has been around for several years and  
stability looks good  at a minimum, there are a good bit of  
forks/stars of the code on github so it tells me this code is being  
used on a daily basis by others.

michael

___________________________________
Michael Slusarz [slusarz at horde.org]