CSS::Minifier::XS(3) User Contributed Perl Documentation CSS::Minifier::XS(3)NAMECSS::Minifier::XS - XS based CSS minifier
SYNOPSIS
use CSS::Minifier::XSqw(minify);
$minified = minify($css);
DESCRIPTION
"CSS::Minifier::XS" is a CSS "minifier"; its designed to remove un-
necessary whitespace and comments from CSS files, while also not
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.
METHODS
minify($css)
Minifies the given $css, returning the minified CSS back to the
caller.
HOW IT WORKS
"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 document:
Pass 1: Tokenize
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.
Pass 2: Collapse
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.
Whitespace
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
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).
Pass 3: Pruning
We then go back through the token list and prune and remove un-
necessary tokens.
Whitespace
Wherever possible, whitespace is removed; before+after comment
blocks, and before+after various symbols/sigils.
Comments
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 removed.
Symbols/Sigils
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 group.
Everything else
We keep everything else; identifiers, quoted literal strings,
symbols/sigils, etc.
Pass 4: Re-assembly
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.
AUTHOR
Graham TerMarsch (cpan@howlingfrog.com)
REPORTING BUGS
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
Copyright (C) 2007-2010, Graham TerMarsch. All Rights Reserved.
This is free software; you can redistribute it and/or modify it under
the same license as Perl itself.
SEE ALSO
"CSS::Minifier".
perl v5.14.1 2010-07-22 CSS::Minifier::XS(3)