Walker_Comment

class Walker_Comment extends Walker {

	/**
	 * What the class handles.
	 *
	 * @since WP-2.7.0
	 * @var string
	 *
	 * @see Walker::$tree_type
	 */
	public $tree_type = 'comment';

	/**
	 * Database fields to use.
	 *
	 * @since WP-2.7.0
	 * @var array
	 *
	 * @see Walker::$db_fields
	 * @todo Decouple this
	 */
	public $db_fields = array ('parent' => 'comment_parent', 'id' => 'comment_ID');

	/**
	 * Starts the list before the elements are added.
	 *
	 * @since WP-2.7.0
	 *
	 * @see Walker::start_lvl()
	 * @global int $comment_depth
	 *
	 * @param string $output Used to append additional content (passed by reference).
	 * @param int    $depth  Optional. Depth of the current comment. Default 0.
	 * @param array  $args   Optional. Uses 'style' argument for type of HTML list. Default empty array.
	 */
	public function start_lvl( &$output, $depth = 0, $args = array() ) {
		$GLOBALS['comment_depth'] = $depth + 1;

		switch ( $args['style'] ) {
			case 'div':
				break;
			case 'ol':
				$output .= '<ol class="children">' . "\n";
				break;
			case 'ul':
			default:
				$output .= '<ul class="children">' . "\n";
				break;
		}
	}

	/**
	 * Ends the list of items after the elements are added.
	 *
	 * @since WP-2.7.0
	 *
	 * @see Walker::end_lvl()
	 * @global int $comment_depth
	 *
	 * @param string $output Used to append additional content (passed by reference).
	 * @param int    $depth  Optional. Depth of the current comment. Default 0.
	 * @param array  $args   Optional. Will only append content if style argument value is 'ol' or 'ul'.
	 *                       Default empty array.
	 */
	public function end_lvl( &$output, $depth = 0, $args = array() ) {
		$GLOBALS['comment_depth'] = $depth + 1;

		switch ( $args['style'] ) {
			case 'div':
				break;
			case 'ol':
				$output .= "</ol><!-- .children -->\n";
				break;
			case 'ul':
			default:
				$output .= "</ul><!-- .children -->\n";
				break;
		}
	}

	/**
	 * Traverses elements to create list from elements.
	 *
	 * This function is designed to enhance Walker::display_element() to
	 * display children of higher nesting levels than selected inline on
	 * the highest depth level displayed. This prevents them being orphaned
	 * at the end of the comment list.
	 *
	 * Example: max_depth = 2, with 5 levels of nested content.
	 *     1
	 *      1.1
	 *        1.1.1
	 *        1.1.1.1
	 *        1.1.1.1.1
	 *        1.1.2
	 *        1.1.2.1
	 *     2
	 *      2.2
	 *
	 * @since WP-2.7.0
	 *
	 * @see Walker::display_element()
	 * @see wp_list_comments()
	 *
	 * @param WP_Comment $element           Comment data object.
	 * @param array      $children_elements List of elements to continue traversing. Passed by reference.
	 * @param int        $max_depth         Max depth to traverse.
	 * @param int        $depth             Depth of the current element.
	 * @param array      $args              An array of arguments.
	 * @param string     $output            Used to append additional content. Passed by reference.
	 */
	public function display_element( $element, &$children_elements, $max_depth, $depth, $args, &$output ) {
		if ( !$element )
			return;

		$id_field = $this->db_fields['id'];
		$id = $element->$id_field;

		parent::display_element( $element, $children_elements, $max_depth, $depth, $args, $output );

		/*
		 * If at the max depth, and the current element still has children, loop over those
		 * and display them at this level. This is to prevent them being orphaned to the end
		 * of the list.
		 */
		if ( $max_depth <= $depth + 1 && isset( $children_elements[$id]) ) {
			foreach ( $children_elements[ $id ] as $child )
				$this->display_element( $child, $children_elements, $max_depth, $depth, $args, $output );

			unset( $children_elements[ $id ] );
		}

	}

	/**
	 * Starts the element output.
	 *
	 * @since WP-2.7.0
	 *
	 * @see Walker::start_el()
	 * @see wp_list_comments()
	 * @global int        $comment_depth
	 * @global WP_Comment $comment
	 *
	 * @param string     $output  Used to append additional content. Passed by reference.
	 * @param WP_Comment $comment Comment data object.
	 * @param int        $depth   Optional. Depth of the current comment in reference to parents. Default 0.
	 * @param array      $args    Optional. An array of arguments. Default empty array.
	 * @param int        $id      Optional. ID of the current comment. Default 0 (unused).
	 */
	public function start_el( &$output, $comment, $depth = 0, $args = array(), $id = 0 ) {
		$depth++;
		$GLOBALS['comment_depth'] = $depth;
		$GLOBALS['comment'] = $comment;

		if ( !empty( $args['callback'] ) ) {
			ob_start();
			call_user_func( $args['callback'], $comment, $args, $depth );
			$output .= ob_get_clean();
			return;
		}

		if ( ( 'pingback' == $comment->comment_type || 'trackback' == $comment->comment_type ) && $args['short_ping'] ) {
			ob_start();
			$this->ping( $comment, $depth, $args );
			$output .= ob_get_clean();
		} elseif ( 'html5' === $args['format'] ) {
			ob_start();
			$this->html5_comment( $comment, $depth, $args );
			$output .= ob_get_clean();
		} else {
			ob_start();
			$this->comment( $comment, $depth, $args );
			$output .= ob_get_clean();
		}
	}

	/**
	 * Ends the element output, if needed.
	 *
	 * @since WP-2.7.0
	 *
	 * @see Walker::end_el()
	 * @see wp_list_comments()
	 *
	 * @param string     $output  Used to append additional content. Passed by reference.
	 * @param WP_Comment $comment The current comment object. Default current comment.
	 * @param int        $depth   Optional. Depth of the current comment. Default 0.
	 * @param array      $args    Optional. An array of arguments. Default empty array.
	 */
	public function end_el( &$output, $comment, $depth = 0, $args = array() ) {
		if ( !empty( $args['end-callback'] ) ) {
			ob_start();
			call_user_func( $args['end-callback'], $comment, $args, $depth );
			$output .= ob_get_clean();
			return;
		}
		if ( 'div' == $args['style'] )
			$output .= "</div><!-- #comment-## -->\n";
		else
			$output .= "</li><!-- #comment-## -->\n";
	}

	/**
	 * Outputs a pingback comment.
	 *
	 * @since WP-3.6.0
	 *
	 * @see wp_list_comments()
	 *
	 * @param WP_Comment $comment The comment object.
	 * @param int        $depth   Depth of the current comment.
	 * @param array      $args    An array of arguments.
	 */
	protected function ping( $comment, $depth, $args ) {
		$tag = ( 'div' == $args['style'] ) ? 'div' : 'li';
?>
		<<?php echo $tag; ?> id="comment-<?php comment_ID(); ?>" <?php comment_class( '', $comment ); ?>>
			<div class="comment-body">
				<?php _e( 'Pingback:' ); ?> <?php comment_author_link( $comment ); ?> <?php edit_comment_link( __( 'Edit' ), '<span class="edit-link">', '</span>' ); ?>
			</div>
<?php
	}

	/**
	 * Outputs a single comment.
	 *
	 * @since WP-3.6.0
	 *
	 * @see wp_list_comments()
	 *
	 * @param WP_Comment $comment Comment to display.
	 * @param int        $depth   Depth of the current comment.
	 * @param array      $args    An array of arguments.
	 */
	protected function comment( $comment, $depth, $args ) {
		if ( 'div' == $args['style'] ) {
			$tag = 'div';
			$add_below = 'comment';
		} else {
			$tag = 'li';
			$add_below = 'div-comment';
		}
?>
		<<?php echo $tag; ?> <?php comment_class( $this->has_children ? 'parent' : '', $comment ); ?> id="comment-<?php comment_ID(); ?>">
		<?php if ( 'div' != $args['style'] ) : ?>
		<div id="div-comment-<?php comment_ID(); ?>" class="comment-body">
		<?php endif; ?>
		<div class="comment-author vcard">
			<?php if ( 0 != $args['avatar_size'] ) echo get_avatar( $comment, $args['avatar_size'] ); ?>
			<?php
				/* translators: %s: comment author link */
				printf( __( '%s <span class="says">says:</span>' ),
					sprintf( '<cite class="fn">%s</cite>', get_comment_author_link( $comment ) )
				);
			?>
		</div>
		<?php if ( '0' == $comment->comment_approved ) : ?>
		<em class="comment-awaiting-moderation"><?php _e( 'Your comment is awaiting moderation.' ) ?></em>
		<br />
		<?php endif; ?>

		<div class="comment-meta commentmetadata"><a href="<?php echo esc_url( get_comment_link( $comment, $args ) ); ?>">
			<?php
				/* translators: 1: comment date, 2: comment time */
				printf( __( '%1$s at %2$s' ), get_comment_date( '', $comment ),  get_comment_time() ); ?></a><?php edit_comment_link( __( '(Edit)' ), '&nbsp;&nbsp;', '' );
			?>
		</div>

		<?php comment_text( $comment, array_merge( $args, array( 'add_below' => $add_below, 'depth' => $depth, 'max_depth' => $args['max_depth'] ) ) ); ?>

		<?php
		comment_reply_link( array_merge( $args, array(
			'add_below' => $add_below,
			'depth'     => $depth,
			'max_depth' => $args['max_depth'],
			'before'    => '<div class="reply">',
			'after'     => '</div>'
		) ) );
		?>

		<?php if ( 'div' != $args['style'] ) : ?>
		</div>
		<?php endif; ?>
<?php
	}

	/**
	 * Outputs a comment in the HTML5 format.
	 *
	 * @since WP-3.6.0
	 *
	 * @see wp_list_comments()
	 *
	 * @param WP_Comment $comment Comment to display.
	 * @param int        $depth   Depth of the current comment.
	 * @param array      $args    An array of arguments.
	 */
	protected function html5_comment( $comment, $depth, $args ) {
		$tag = ( 'div' === $args['style'] ) ? 'div' : 'li';
?>
		<<?php echo $tag; ?> id="comment-<?php comment_ID(); ?>" <?php comment_class( $this->has_children ? 'parent' : '', $comment ); ?>>
			<article id="div-comment-<?php comment_ID(); ?>" class="comment-body">
				<footer class="comment-meta">
					<div class="comment-author vcard">
						<?php if ( 0 != $args['avatar_size'] ) echo get_avatar( $comment, $args['avatar_size'] ); ?>
						<?php
							/* translators: %s: comment author link */
							printf( __( '%s <span class="says">says:</span>' ),
								sprintf( '<b class="fn">%s</b>', get_comment_author_link( $comment ) )
							);
						?>
					</div><!-- .comment-author -->

					<div class="comment-metadata">
						<a href="<?php echo esc_url( get_comment_link( $comment, $args ) ); ?>">
							<time datetime="<?php comment_time( 'c' ); ?>">
								<?php
									/* translators: 1: comment date, 2: comment time */
									printf( __( '%1$s at %2$s' ), get_comment_date( '', $comment ), get_comment_time() );
								?>
							</time>
						</a>
						<?php edit_comment_link( __( 'Edit' ), '<span class="edit-link">', '</span>' ); ?>
					</div><!-- .comment-metadata -->

					<?php if ( '0' == $comment->comment_approved ) : ?>
					<p class="comment-awaiting-moderation"><?php _e( 'Your comment is awaiting moderation.' ); ?></p>
					<?php endif; ?>
				</footer><!-- .comment-meta -->

				<div class="comment-content">
					<?php comment_text(); ?>
				</div><!-- .comment-content -->

				<?php
				comment_reply_link( array_merge( $args, array(
					'add_below' => 'div-comment',
					'depth'     => $depth,
					'max_depth' => $args['max_depth'],
					'before'    => '<div class="reply">',
					'after'     => '</div>'
				) ) );
				?>
			</article><!-- .comment-body -->
<?php
	}
}