CSS::Minifier::XS(3pm)

1CSS::Minifier::XS(3)  User Contributed Perl Documentation CSS::Minifier::XS(3)
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NAME

6       CSS::Minifier::XS - XS based CSS minifier
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SYNOPSIS

9         use CSS::Minifier::XS qw(minify);
10         my $css      = '...';
11         my $minified = minify($css);
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DESCRIPTION

14       "CSS::Minifier::XS" is a CSS "minifier"; its designed to remove
15       unnecessary whitespace and comments from CSS files, while also not
16       breaking the CSS.
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18       "CSS::Minifier::XS" is similar in function to "CSS::Minifier", but is
19       substantially faster as its written in XS and not just pure Perl.
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METHODS

22       minify($css)
23           Minifies the given $css, returning the minified CSS back to the
24           caller.
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HOW IT WORKS

27       "CSS::Minifier::XS" minifies the CSS by removing unnecessary whitespace
28       from CSS documents.  Comment blocks are also removed, except when (a)
29       they contain the word "copyright" in them, or (b) they're needed to
30       implement the "Mac/IE Comment Hack".
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32       Internally, the minification is done by taking multiple passes through
33       the CSS document:
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35   Pass 1: Tokenize
36       First, we go through and parse the CSS document into a series of tokens
37       internally.  The tokenizing process does not check to make sure that
38       you've got syntactically valid CSS, it just breaks up the text into a
39       stream of tokens suitable for processing by the subsequent stages.
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41   Pass 2: Collapse
42       We then march through the token list and collapse certain tokens down
43       to their smallest possible representation.  If they're still included
44       in the final results we only want to include them at their shortest.
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46       Whitespace
47           Runs of multiple whitespace characters are reduced down to a single
48           whitespace character.  If the whitespace contains any "end of line"
49           (EOL) characters, then the end result is the first EOL character
50           encountered.  Otherwise, the result is the first whitespace
51           character in the run.
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53       Comments
54           Comments implementing the "Mac/IE Comment Hack" are collapsed down
55           to the smallest possible comment that would still implement the
56           hack ("/*\*/" to start the hack, and "/**/" to end it).
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58       Zero Units
59           Zero Units (e.g. "0px") are reduced down to just "0", as the CSS
60           specification indicates that the unit is not required when its a
61           zero value.
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63   Pass 3: Pruning
64       We then go back through the token list and prune and remove unnecessary
65       tokens.
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67       Whitespace
68           Wherever possible, whitespace is removed; before+after comment
69           blocks, and before+after various symbols/sigils.
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71       Comments
72           Comments that either (a) are needed to implement the "Mac/IE
73           Comment Hack", or that (b) contain the word "copyright" in them are
74           preserved.  All other comments are removed.
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76       Symbols/Sigils
77           Semi-colons that are immediately followed by a closing brace (e.g.
78           ";}") are removed; semi-colons are needed to separate multiple
79           declarations, but aren't required at the end of a group.
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81       Everything else
82           We keep everything else; identifiers, quoted literal strings,
83           symbols/sigils, etc.
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85   Pass 4: Re-assembly
86       Lastly, we go back through the token list and re-assemble it all back
87       into a single CSS string, which is then returned back to the caller.
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AUTHOR

90       Graham TerMarsch (cpan@howlingfrog.com)
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COPYRIGHT

93       Copyright (C) 2007-, Graham TerMarsch.  All Rights Reserved.
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95       This is free software; you can redistribute it and/or modify it under
96       the same license as Perl itself.
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