codenothing/CSSCompressor

/**
 * 
 * Function Units
 * 
 * @author: Corey Hart <http://www.codenothing.com>
 * @description: General whitespace removal and unit compression of css functions
 * 
 * @before:
 *     .example {
 *         background: new-rule( top, 10px, 0.5px, 15.5, foo );
 *     }
 * 
 * @after:
 *     .example {
 *         background: new-rule(top,10px,.5px,15.5,foo);
 *     }
 * 
 */

var CSSCompressor = global.CSSCompressor,
    StringIterator = CSSCompressor.StringIterator,
    rfunction = /^([a-z\-_]+)\((.*?)\)$/i;

CSSCompressor.rule({

    name: 'Function Units',
    type: CSSCompressor.RULE_TYPE_VALUE,
    group: 'Misc',
    description: "General whitespace removal and unit compression of css functions",

    callback: function( value, position, compressor ) {
        var m = rfunction.exec( value ),
            iter = new StringIterator( ( m || [] )[ 2 ] || '' ),
            string = '',
            parts = [];

        if ( iter.length ) {
            iter.each(function( c ) {
                if ( c == "\\" ) {
                    string += c + iter.skip();
                }
                else if ( c == ',' ) {
                    parts.push( string.trim() );
                    string = '';
                }
                else if ( c == "'" || c == '"' || c == '(' ) {
                    string += c + iter.seek( c == '(' ? ')' : c );
                }
                else {
                    string += c;
                }
            });

            // Generate new value string
            next = m[ 1 ] + '(';
            parts.push( string.trim() );
            parts.forEach(function( part, index ) {
                if ( index > 0 ) {
                    next += ',';
                }

                next += compressor.value( part, position );
            });
            next += ')';

            // Only log if there is a change
            if ( next !== value ) {
                compressor.log(
                    "Trimming whitespace in grouping '" + value + "' => '" + next + "'",
                    position
                );

                return next;
            }
        }
    }

});