NAME¶
JavaScript::Minifier::XS - XS based JavaScript minifier
SYNOPSIS¶
use JavaScript::Minifier::XS qw(minify);
$minified = minify($js);
DESCRIPTION¶
"JavaScript::Minifier::XS" is a JavaScript "minifier"; its
designed to remove un-necessary whitespace and comments from JavaScript files,
which also
not breaking the JavaScript.
"JavaScript::Minifier::XS" is similar in function to
"JavaScript::Minifier", but is substantially faster as its written
in XS and not just pure Perl.
METHODS¶
- minify($js)
- Minifies the given $js, returning the minified JavaScript back to the
caller.
HOW IT WORKS¶
"JavaScript::Minifier::XS" minifies the JavaScript by removing
un-necessary whitespace from JavaScript documents. Comments (both block and
line) are also removed,
except when (a) they contain the word
"copyright" in them, or (b) they're needed to implement "IE
Conditional Compilation".
Internally, the minification process is done by taking multiple passes through
the JavaScript document:
Pass 1: Tokenize¶
First, we go through and parse the JavaScript document into a series of tokens
internally. The tokenizing process
does not check to make sure you've
got syntactically valid JavaScript, 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.
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 are either (a) IE conditional compilation comments, or that
(b) contain the word "copyright" in them are preserved.
All other comments (line and block) are removed.
- 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 JavaScript 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=JavaScript::Minifier::XS>),
and be sure to include the JavaScript that you're having troubles minifying.
COPYRIGHT¶
Copyright (C) 2007-2008, 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¶
"JavaScript::Minifier".