clean-css-pre-2.1.0


What is clean-css?

Clean-css is a fast and efficient Node.js library for minifying CSS files.

According to tests it is one of the best available.

Usage

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``
Node.js 0.8.0+ (tested on CentOS, Ubuntu, OS X 10.6+, and Windows 7+)
`

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`
npm install clean-css
`

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#### Command-line interface (CLI)

`
npm update clean-css
`

or point package.json to version 2.x. That's it!

#### Node.js module

Update clean-css as for CLI above.
Then change your JavaScript code from:

`js
var minimized = CleanCSS.process(source, options);
`

into

`js
var minimized = new CleanCSS(options).minify(source);
`

And you are done.

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Clean-css accepts the following command line arguments (please make sure
you use as the very last argument to avoid potential issues):

`
cleancss [options]

-h, --help Output usage information
-v, --version Output the version number
-b, --keep-line-breaks Keep line breaks
--s0 Remove all special comments, i.e. /! comment /
--s1 Remove all special comments but the first one
-r, --root [root-path] A root path to which resolve absolute @import rules
and rebase relative URLs
-o, --output [output-file] Use [output-file] as output instead of STDOUT
-s, --skip-import Disable @import processing
--skip-rebase Disable URLs rebasing
--skip-advanced Disable advanced optimizations - selector & property merging,
reduction, etc.
--selectors-merge-mode [ie8|*] DEPRECATED: Use --compatibility switch
-c, --compatibility [ie7|ie8] Force compatibility mode
-d, --debug Shows debug information (minification time & compression efficiency)
`

#### Examples:

To minify a public.css file into public-min.css do:

`
cleancss -o public-min.css public.css
`

To minify the same public.css into the standard output skip the -o parameter:

`
cleancss public.css
`

More likely you would like to concatenate a couple of files.
If you are on a Unix-like system:

`bash
cat one.css two.css three.css | cleancss -o merged-and-minified.css
`

On Windows:

`bat
type one.css two.css three.css | cleancss -o merged-and-minified.css
`

Or even gzip the result at once:

`bash
cat one.css two.css three.css | cleancss | gzip -9 -c > merged-minified-and-gzipped.css.gz
`

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`js
var CleanCSS = require('clean-css');
var source = 'a{font-weight:bold;}';
var minimized = new CleanCSS().minify(source);
`

CleanCSS constructor accepts a hash as a parameter, i.e.,
new CleanCSS(options).minify(source) with the following options available:

keepSpecialComments - for keeping all (default), 1 for keeping first one only, 0 for removing all
* keepBreaks - whether to keep line breaks (default is false)
* benchmark - turns on benchmarking mode measuring time spent on cleaning up
(run npm run bench to see example)
* root - path to resolve absolute @import rules and rebase relative URLs
* relativeTo - path with which to resolve relative @import rules and URLs
* processImport - whether to process @import rules
* noRebase - whether to skip URLs rebasing
* noAdvanced - set to true to disable advanced optimizations - selector & property merging, reduction, etc.
selectorsMergeMode - ie8 for IE8 compatibility mode, for merging all (default)
* debug - set to true to get minification statistics under stats property (see test/custom-test.js for examples)

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See grunt-contrib-cssmin plugin.

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First clone the source, then run:

* npm run bench for clean-css benchmarks (see test/bench.js for details)
* npm run check to check JS sources with JSHint
* npm test for the test suite

How to contribute to clean-css?

1. Fork it.
2. Add test(s) veryfying the problem.
3. Fix the problem.
4. Make sure all tests still pass (npm test).
5. Make sure your code doesn't break style rules (npm run check).
6. Send a PR.

If you wonder where to add tests, go for:

* test/unit-test.js if it's a simple scenario
* test/data/... if it's a complex scenario (just add two files, input and expected output)
* test/binary-test.js if it's related to bin/cleancss binary
* test/module-test.js if it's related to importing clean-css as a module
* test/protocol-imports-test.js if it fixes anything related to protocol @imports

Tips & Tricks

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Use the /! notation instead of the standard one /:

`css
/*!
Important comments included in minified output.
*/
`

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Clean-css will handle it automatically for you (since version 1.1) in the following cases:

* When using the CLI:
1. Use an output path via -o/--output to rebase URLs as relative to the output file.
2. Use a root path via -r/--root to rebase URLs as absolute from the given root path.
3. If you specify both then -r/--root takes precendence.
* When using clean-css as a library:
1. Use a combination of relativeTo and target options for relative rebase (same as 1 in CLI).
2. Use a combination of relativeTo and root options for absolute rebase (same as 2 in CLI).
3. root takes precendence over target as in CLI.

Acknowledgments

* Vincent Voyer (@vvo) for a patch with better
empty element regex and for inspiring us to do many performance improvements
in 0.4 release.
* Isaac (@facelessuser) for pointing out
a flaw in clean-css' stateless mode.
* Jan Michael Alonzo (@jmalonzo) for a patch
removing node.js' old sys package.
* @XhmikosR for suggesting new features
(option to remove special comments and strip out URLs quotation) and
pointing out numerous improvements (JSHint, media queries).
* Anthony Barre (@abarre) for improvements to
@import processing, namely introducing the --skip-import /
processImport options.
* Simon Altschuler (@altschuler) for fixing
@import` processing inside comments.

License

Clean-css is released under the MIT License.