CSS::Minifier::XS - XS based CSS minifier
use CSS::Minifier::XS qw(minify);
$minified = minify($css);
"CSS::Minifier::XS" is a CSS "minifier"; its designed to
remove un-necessary whitespace and comments from CSS files, while also
breaking the CSS.
"CSS::Minifier::XS" is similar in function to
"CSS::Minifier", but is substantially faster as its written in XS
and not just pure Perl.
- Minifies the given $css, returning the minified CSS back to
"CSS::Minifier::XS" minifies the CSS by removing un-necessary
whitespace from CSS documents. Comment blocks are also removed, except
when (a) they contain the word "copyright" in them, or (b) they're
needed to implement the "Mac/IE Comment Hack".
Internally, the minification is done by taking multiple passes through the CSS
First, we go through and parse the CSS document into a series of tokens
internally. The tokenizing process does not
check to make sure that
you've got syntactically valid CSS, it just breaks up the text into a stream
of tokens suitable for processing by the subsequent stages.
We then march through the token list and collapse certain tokens down to their
smallest possible representation. If
they're still included in the
final results we only want to include them at their shortest.
- Runs of multiple whitespace characters are reduced down to
a single whitespace character. If the whitespace contains any "end of
line" (EOL) characters, then the end result is the first EOL
character encountered. Otherwise, the result is the first whitespace
character in the run.
- Comments implementing the "Mac/IE Comment Hack"
are collapsed down to the smallest possible comment that would still
implement the hack ("/*\*/" to start the hack, and
"/**/" to end it).
- Zero Units
- Zero Units (e.g. "0px") are reduced down to just
"0", as the CSS specification indicates that the unit is not
required when its a zero value.
We then go back through the token list and prune and remove un-necessary tokens.
- Wherever possible, whitespace is removed; before+after
comment blocks, and before+after various symbols/sigils.
- Comments that either (a) are needed to implement the
"Mac/IE Comment Hack", or that (b) contain the word
"copyright" in them are preserved. All other comments are
- Semi-colons that are immediately followed by a closing
brace (e.g. ";}") are removed; semi-colons are needed to
separate multiple declarations, but aren't required at the end of a
- Everything else
- We keep everything else; identifiers, quoted literal
strings, symbols/sigils, etc.
Lastly, we go back through the token list and re-assemble it all back into a
single CSS string, which is then returned back to the caller.
Graham TerMarsch (firstname.lastname@example.org)
Please report bugs via RT
(<http://rt.cpan.org/Dist/Display.html?Queue=CSS::Minifier::XS>), and be
sure to include the CSS that you're having troubles minifying.
Copyright (C) 2007-, Graham TerMarsch. All Rights Reserved.
This is free software; you can redistribute it and/or modify it under the same
license as Perl itself.