/home/arranoyd/magicraft/wp-content/themes/massive-dynamic/lib/portfolio-walker.php
<?php

class PixflowPortfolioWalker extends Walker_Category {

    function start_el(&$output, $category, $depth = 0, $args = array(), $id = 0)
    {
        extract($args);
        $cat_name = esc_attr( $category->name);
        $cat_name = apply_filters( 'list_cats', $cat_name, $category );

        $link = "<a href=\"#\" data-filter=\".term-$category->term_id\" ";

        if ( $use_desc_for_title == 0 || empty($category->description) )
            $link .= 'title="' . sprintf(esc_attr__( 'View all items filed under %s', 'massive-dynamic' ), $cat_name) . '" >';
        else
            $link .= 'title="' . esc_attr( strip_tags( apply_filters( 'category_description', $category->description, $category ) ) ) . '" >';

        $link .= $cat_name . '</a>';

        if ( isset($current_category) && $current_category )
            $_current_category = get_category( $current_category );


        $class = 'cat-item cat-item-'.$category->term_id;

        if ( isset($current_category) && ($category->term_id === $current_category) )
        {
            $class .=  ' current';
        }
        elseif ( isset($_current_category) && ($category->term_id === $_current_category->parent) )
        {
            $class .=  ' current-parent';
        }

        $output .= "<li class=\"$class\">$link";
    }
}