Additional CSS class in wp_list_pages when a page has children

[Jonnyauk]

A great addition to the wp_list_pages function would be to add an extra CSS class of 'page_has_children' (or similar) to a list item for when it has child pages.

This would enable theme authors to style the list items with CSS to differentiate between those pages that have child pages, and those that don't at whatever depth you are viewing in really simple CSS.

Here is how it could be implemented in the WP3.0 codebase. I have simply amended the 'start_el' function as shown below.

FILE: wp-includes/classes.php - from line 1173

/**
 * @see Walker::start_el()
 * @since 2.1.0
 *
 * @param string $output Passed by reference. Used to append additional content.
 * @param object $page Page data object.
 * @param int $depth Depth of page. Used for padding.
 * @param int $current_page Page ID.
 * @param array $args
 */
function start_el(&$output, $page, $depth, $args, $current_page) {
	if ( $depth )
		$indent = str_repeat("\t", $depth);
	else
		$indent = '';

	extract($args, EXTR_SKIP);
	$css_class = array('page_item', 'page-item-'.$page->ID);
	
	//JA ADDITION START 1 of 2 - DETECT IF PAGE HAS CHILDREN START
	$has_children = wp_list_pages('&child_of='.$page->ID.'&echo=0');
	//JA ADDITION END 1 of 2 - DETECT IF PAGE HAS CHILDREN
	
	if ( !empty($current_page) ) {
		$_current_page = get_page( $current_page );
		if ( isset($_current_page->ancestors) && in_array($page->ID, (array) $_current_page->ancestors) )
			$css_class[] = 'current_page_ancestor';
		if ( $page->ID == $current_page )
			$css_class[] = 'current_page_item';

		//JA ADDITION START 2 of 2 - DETECT IF PAGE HAS CHILDREN START
		if ( !empty($has_children) )
			$css_class[] = 'page_has_children';
		//JA ADDITION START 2 of 2 - DETECT IF PAGE HAS CHILDREN END

		elseif ( $_current_page && $page->ID == $_current_page->post_parent )
			$css_class[] = 'current_page_parent';
	} elseif ( $page->ID == get_option('page_for_posts') ) {
		$css_class[] = 'current_page_parent';
	}

	$css_class = implode(' ', apply_filters('page_css_class', $css_class, $page));

	$output .= $indent . '<li class="' . $css_class . '"><a href="' . get_page_link($page->ID) . '" title="' . esc_attr( wp_strip_all_tags( apply_filters( 'the_title', $page->post_title, $page->ID ) ) ) . '">' . $link_before . apply_filters( 'the_title', $page->post_title, $page->ID ) . $link_after . '</a>';

	if ( !empty($show_date) ) {
		if ( 'modified' == $show_date )
			$time = $page->post_modified;
		else
			$time = $page->post_date;

		$output .= " " . mysql2date($date_format, $time);
	}
}

Actually, you already have $has_children set. See patch

Related: #14041

Great - that makes it even neater! You can see how this would be useful for page menu styling with wp_list_pages - I'll look forward to using this in 3.1, thank you!