codenothing/CSSCompressor

/**
 * 
 * Duplicate Properties
 * 
 * @author: Corey Hart <http://www.codenothing.com>
 * @description: Removes multiply defined properties
 * 
 * @before:
 *     .example {
 *         color: red;
 *         margin: 10px;
 *         color: green;
 *     }
 *
 * 
 * @after:
 *     .example {
 *         margin: 10px;
 *         color: green;
 *     }
 * 
 */

var CSSCompressor = global.CSSCompressor;

CSSCompressor.rule({

    name: 'Duplicate Properties',
    type: CSSCompressor.RULE_TYPE_BLOCK,
    group: 'Trim',
    description: "Removes multiply defined properties",
    priority: CSSCompressor.PRIORITY_LOWEST,

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

        for ( var i = -1, j, rule, next; ++i < branch.rules.length; ) {
            rule = branch.rules[ i ];

            for ( j = i; ++j < branch.rules.length; ) {
                next = branch.rules[ j ];

                if ( rule.property === next.property ) {
                    compressor.log(
                        "Removing duplicate property '" + rule.property + "'",
                        [ rule.position, next.position ]
                    );
                    CSSCompressor.removeItem( branch.rules, rule );
                    i--;
                    break;
                }
            }
        }
    }

});