codenothing/CSSCompressor

/**
 * 
 * Lowercase Selectors
 * 
 * @author: Corey Hart <http://www.codenothing.com>
 * @description: Converts element selectors to lowercase for better gzip compression
 * 
 * @before:
 *     BODY {
 *         color: red;
 *     }
 * 
 * @after:
 *     body {
 *         color: red;
 *     }
 * 
 */

var CSSCompressor = global.CSSCompressor,
    ralpha = /^[a-z]+$/i,
    ruppercase = /[A-Z]/;

CSSCompressor.rule({

    name: 'Lowercase Selectors',
    type: CSSCompressor.RULE_TYPE_BLOCK,
    group: 'GZIP',
    description: "Converts element selectors to lowercase for better gzip compression",

    callback: function( branch, compressor ) {
        if ( ! branch.selector || ! branch.parts || ! branch.parts.length ) {
            return;
        }

        branch.parts.forEach(function( part, index ) {
            var newsubs = [];

            if ( CSSCompressor.isArray( part ) ) {
                part.forEach(function( subpart ) {
                    if ( ralpha.exec( subpart ) && ruppercase.exec( subpart ) ) {
                        compressor.log(
                            "Lowercasing selector '" + subpart + "' => '" + subpart.toLowerCase() + "'",
                            branch.position
                        );

                        subpart = subpart.toLowerCase();
                    }

                    newsubs.push( subpart );
                });

                branch.parts[ index ] = newsubs;
            }
            else {
                if ( ralpha.exec( part ) && ruppercase.exec( part ) ) {
                    compressor.log(
                        "Lowercasing selector '" + part + "' => '" + part.toLowerCase() + "'",
                        branch.position
                    );

                    branch.parts[ index ] = part.toLowerCase();
                }
            }
        });
    }

});