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.IX Title "CSS::Minifier::XS 3pm"
.TH CSS::Minifier::XS 3pm 2024-03-07 "perl v5.38.2" "User Contributed Perl Documentation"
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.SH NAME
CSS::Minifier::XS \- XS based CSS minifier
.SH SYNOPSIS
.IX Header "SYNOPSIS"
.Vb 3
\&  use CSS::Minifier::XS qw(minify);
\&  my $css      = \*(Aq...\*(Aq;
\&  my $minified = minify($css);
.Ve
.SH DESCRIPTION
.IX Header "DESCRIPTION"
\&\f(CW\*(C`CSS::Minifier::XS\*(C'\fR is a CSS "minifier"; its designed to remove unnecessary
whitespace and comments from CSS files, while also \fBnot\fR breaking the CSS.
.PP
\&\f(CW\*(C`CSS::Minifier::XS\*(C'\fR is similar in function to \f(CW\*(C`CSS::Minifier\*(C'\fR, but is
substantially faster as its written in XS and not just pure Perl.
.SH METHODS
.IX Header "METHODS"
.IP minify($css) 4
.IX Item "minify($css)"
Minifies the given \f(CW$css\fR, returning the minified CSS back to the caller.
.SH "HOW IT WORKS"
.IX Header "HOW IT WORKS"
\&\f(CW\*(C`CSS::Minifier::XS\*(C'\fR minifies the CSS by removing unnecessary whitespace from
CSS documents.  Comment blocks are also removed, \fIexcept\fR when (a) they
contain the word "copyright" in them, or (b) they're needed to implement the
"Mac/IE Comment Hack".
.PP
Internally, the minification is done by taking multiple passes through the CSS
document:
.SS "Pass 1: Tokenize"
.IX Subsection "Pass 1: Tokenize"
First, we go through and parse the CSS document into a series of tokens
internally.  The tokenizing process \fBdoes not\fR 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.
.SS "Pass 2: Collapse"
.IX Subsection "Pass 2: Collapse"
We then march through the token list and collapse certain tokens down to their
smallest possible representation.  \fIIf\fR they're still included in the final
results we only want to include them at their shortest.
.IP Whitespace 4
.IX Item "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 \fIfirst\fR EOL character encountered.  Otherwise, the
result is the first whitespace character in the run.
.IP Comments 4
.IX Item "Comments"
Comments implementing the "Mac/IE Comment Hack" are collapsed down to the
smallest possible comment that would still implement the hack ("/*\e*/" to start
the hack, and "/**/" to end it).
.IP "Zero Units" 4
.IX Item "Zero Units"
Zero Units (e.g. \f(CW\*(C`0px\*(C'\fR) are reduced down to just "0", as the CSS specification
indicates that the unit is not required when its a zero value.
.SS "Pass 3: Pruning"
.IX Subsection "Pass 3: Pruning"
We then go back through the token list and prune and remove unnecessary
tokens.
.IP Whitespace 4
.IX Item "Whitespace"
Wherever possible, whitespace is removed; before+after comment blocks, and
before+after various symbols/sigils.
.IP Comments 4
.IX Item "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.  \fBAll\fR other
comments are removed.
.IP Symbols/Sigils 4
.IX Item "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.
.IP "Everything else" 4
.IX Item "Everything else"
We keep everything else; identifiers, quoted literal strings, symbols/sigils,
etc.
.SS "Pass 4: Re-assembly"
.IX Subsection "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.
.SH AUTHOR
.IX Header "AUTHOR"
Graham TerMarsch (cpan@howlingfrog.com)
.SH COPYRIGHT
.IX Header "COPYRIGHT"
Copyright (C) 2007\-, Graham TerMarsch.  All Rights Reserved.
.PP
This is free software; you can redistribute it and/or modify it under the same
license as Perl itself.
.SH "SEE ALSO"
.IX Header "SEE ALSO"
\&\f(CW\*(C`CSS::Minifier\*(C'\fR.