Add a new menu called category-menu:
if( function_exists( "wp_nav_menu' ) )
{
add_theme_support( 'nav-menus' );
register_nav_menus( array(
'primary-menu' => __( 'Primary Menu', 'woothemes' )
));
register_nav_menus( array(
'top-menu' => __( 'Top Menu', 'woothemes' )
));
register_nav_menus( array(
'category-menu' => __( 'Category Menu', 'woothemes' )
));
}
And output it with the conditional is_category():
if( function_exists( 'has_nav_menu' ) && has_nav_menu( 'primary-menu' ) )
{
// On category 'Cheese'
if( is_category( 'Cheese' ) )
{
echo '<h3>' . woo_get_menu_name( 'category-menu' ) . '</h3>';
wp_nav_menu( array(
'sort_column' => 'menu_order',
'container' => 'ul',
'menu_id' => 'main-nav',
'menu_class' => 'nav fl',
'theme_location' => 'category-menu'
));
}
else
{
echo '<h3>' . woo_get_menu_name( 'primary-menu' ) . '</h3>';
wp_nav_menu( array(
'sort_column' => 'menu_order',
'container' => 'ul',
'menu_id' => 'main-nav',
'menu_class' => 'nav fl',
'theme_location' => 'primary-menu'
));
}
}