View difference between Paste ID: U2ZNM4eQ and u510cJ8D

 // Modified from http://www.rarescosma.com/2010/11/add-a-class-to-wp_nav_menu-items-with-urls-included-in-the-current-url/
 // Need to add a class (using 'current-menu-item' to the nav menu to highlight it
 // when on custom post type pages (e.g. "/movies/" )
 // Calendar needs to look for "Calendar, Venues,
 // (and in this case Organizers, if you've updated the post_type with a slug)
 function add_parent_url_menu_class( $classes = array(), $item = false ) {
 	// Get current URL
 	$current_url = current_url();
 
 	// Get homepage URL
 	$homepage_url = trailingslashit( get_bloginfo( 'url' ) );
 
 	// Exclude 404 and homepage
 	if( is_404() or $item->url == $homepage_url ) return $classes;
 
 	// if $item->url can be found in $current_url
 	// OR if $current_url (haystack) contains organizer, venue, events
 	// AND $item->url is blah/calendar, add class
 	if ( strstr( $current_url, $item->url) || ( ( strstr( $current_url, '/events/' ) || strstr ($current_url, '/organizer/') || strstr($current_url,'/venue/') )  && strstr( $item->url, '/calendar/') ) ) {
 		// Add the 'current-menu-item' class
 		$classes[] = 'current-menu-item';
 	}
 
 	return $classes;
 }
 add_filter( 'nav_menu_css_class', 'add_parent_url_menu_class', 10, 2 );
 
 // this is a helper function to the above add_parent_url_menu_class;
 // it checks the current url and pulls all the universal stuff out
 function current_url() {
 	// Protocol
 	$url = ( 'on' == $_SERVER['HTTPS'] ) ? 'https://' : 'http://';
 
 	$url .= $_SERVER['SERVER_NAME'];
 
 	// Port
 	$url .= ( '80' == $_SERVER['SERVER_PORT'] ) ? '' : ':' . $_SERVER['SERVER_PORT'];
 
 	$url .= $_SERVER['REQUEST_URI'];
 
 	return trailingslashit( $url );
 }