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         $minified = minify($css);
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DESCRIPTION

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

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

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

89       Graham TerMarsch (cpan@howlingfrog.com)
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REPORTING BUGS

92       Please report bugs via RT
93       (<http://rt.cpan.org/Dist/Display.html?Queue=CSS::Minifier::XS>), and
94       be sure to include the CSS that you're having troubles minifying.
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COPYRIGHT

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