<?php
/**
* Post API: Walker_Page class
*
* @package WordPress
* @subpackage Template
* @since 4.4.0
*/

/**
* Core walker class used to create an HTML list of pages.
*
* @since 2.1.0
*
* @see Walker
*/
class Walker_Page extends Walker {

/**
* What the class handles.
*
* @since 2.1.0
* @var string
*
* @see Walker::$tree_type
*/
public $tree_type = 'page';

/**
* Database fields to use.
*
* @since 2.1.0
* @var string[]
*
* @see Walker::$db_fields
* @todo Decouple this.
*/
public $db_fields = array(
'parent' => 'post_parent',
'id' => 'ID',
);

/**
* Outputs the beginning of the current level in the tree before elements are output.
*
* @since 2.1.0
*
* @see Walker::start_lvl()
*
* @param string $output Used to append additional content (passed by reference).
* @param int $depth Optional. Depth of page. Used for padding. Default 0.
* @param array $args Optional. Arguments for outputting the next level.
* Default empty array.
*/
public function start_lvl( &$output, $depth = 0, $args = array() ) {
if ( isset( $args['item_spacing'] ) && 'preserve' === $args['item_spacing'] ) {
$t = "\t";
$n = "\n";
} else {
$t = '';
$n = '';
}
$indent = str_repeat( $t, $depth );
$output .= "{$n}{$indent}<ul class='children'>{$n}";
}

/**
* Outputs the end of the current level in the tree after elements are output.
*
* @since 2.1.0
*
* @see Walker::end_lvl()
*
* @param string $output Used to append additional content (passed by reference).
* @param int $depth Optional. Depth of page. Used for padding. Default 0.
* @param array $args Optional. Arguments for outputting the end of the current level.
* Default empty array.
*/
public function end_lvl( &$output, $depth = 0, $args = array() ) {
if ( isset( $args['item_spacing'] ) && 'preserve' === $args['item_spacing'] ) {
$t = "\t";
$n = "\n";
} else {
$t = '';
$n = '';
}
$indent = str_repeat( $t, $depth );
$output .= "{$indent}</ul>{$n}";
}

/**
* Outputs the beginning of the current element in the tree.
*
* @see Walker::start_el()
* @since 2.1.0
* @since 5.9.0 Renamed `$page` to `$data_object` and `$current_page` to `$current_object_id`
* to match parent class for PHP 8 named parameter support.
*
* @param string $output Used to append additional content. Passed by reference.
* @param WP_Post $data_object Page data object.
* @param int $depth Optional. Depth of page. Used for padding. Default 0.
* @param array $args Optional. Array of arguments. Default empty array.
* @param int $current_object_id Optional. ID of the current page. Default 0.
*/
public function start_el( &$output, $data_object, $depth = 0, $args = array(), $current_object_id = 0 ) {
// Restores the more descriptive, specific name for use within this method.
$page = $data_object;

$current_page_id = $current_object_id;

if ( isset( $args['item_spacing'] ) && 'preserve' === $args['item_spacing'] ) {
$t = "\t";
$n = "\n";
} else {
$t = '';
$n = '';
}
if ( $depth ) {
$indent = str_repeat( $t, $depth );
} else {
$indent = '';
}

$css_class = array( 'page_item', 'page-item-' . $page->ID );

if ( isset( $args['pages_with_children'][ $page->ID ] ) ) {
$css_class[] = 'page_item_has_children';
}

if ( ! empty( $current_page_id ) ) {
$_current_page = get_post( $current_page_id );

if ( $_current_page && in_array( $page->ID, $_current_page->ancestors, true ) ) {
$css_class[] = 'current_page_ancestor';
}

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

/**
* Filters the list of CSS classes to include with each page item in the list.
*
* @since 2.8.0
*
* @see wp_list_pages()
*
* @param string[] $css_class An array of CSS classes to be applied to each list item.
* @param WP_Post $page Page data object.
* @param int $depth Depth of page, used for padding.
* @param array $args An array of arguments.
* @param int $current_page_id ID of the current page.
*/
$css_classes = implode( ' ', apply_filters( 'page_css_class', $css_class, $page, $depth, $args, $current_page_id ) );
$css_classes = $css_classes ? ' class="' . esc_attr( $css_classes ) . '"' : '';

if ( '' === $page->post_title ) {
/* translators: %d: ID of a post. */
$page->post_title = sprintf( __( '#%d (no title)' ), $page->ID );
}

$args['link_before'] = empty( $args['link_before'] ) ? '' : $args['link_before'];
$args['link_after'] = empty( $args['link_after'] ) ? '' : $args['link_after'];

$atts = array();
$atts['href'] = get_permalink( $page->ID );
$atts['aria-current'] = ( $page->ID === (int) $current_page_id ) ? 'page' : '';

/**
* Filters the HTML attributes applied to a page menu item's anchor element.
*
* @since 4.8.0
*
* @param array $atts {
* The HTML attributes applied to the menu item's `<a>` element, empty strings are ignored.
*
* @type string $href The href attribute.
* @type string $aria-current The aria-current attribute.
* }
* @param WP_Post $page Page data object.
* @param int $depth Depth of page, used for padding.
* @param array $args An array of arguments.
* @param int $current_page_id ID of the current page.
*/
$atts = apply_filters( 'page_menu_link_attributes', $atts, $page, $depth, $args, $current_page_id );

$attributes = '';
foreach ( $atts as $attr => $value ) {
if ( is_scalar( $value ) && '' !== $value && false !== $value ) {
$value = ( 'href' === $attr ) ? esc_url( $value ) : esc_attr( $value );
$attributes .= ' ' . $attr . '="' . $value . '"';
}
}

$output .= $indent . sprintf(
'<li%s><a%s>%s%s%s</a>',
$css_classes,
$attributes,
$args['link_before'],
/** This filter is documented in wp-includes/post-template.php */
apply_filters( 'the_title', $page->post_title, $page->ID ),
$args['link_after']
);

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

$date_format = empty( $args['date_format'] ) ? '' : $args['date_format'];
$output .= ' ' . mysql2date( $date_format, $time );
}
}

/**
* Outputs the end of the current element in the tree.
*
* @since 2.1.0
* @since 5.9.0 Renamed `$page` to `$data_object` to match parent class for PHP 8 named parameter support.
*
* @see Walker::end_el()
*
* @param string $output Used to append additional content. Passed by reference.
* @param WP_Post $data_object Page data object. Not used.
* @param int $depth Optional. Depth of page. Default 0 (unused).
* @param array $args Optional. Array of arguments. Default empty array.
*/
public function end_el( &$output, $data_object, $depth = 0, $args = array() ) {
if ( isset( $args['item_spacing'] ) && 'preserve' === $args['item_spacing'] ) {
$t = "\t";
$n = "\n";
} else {
$t = '';
$n = '';
}
$output .= "</li>{$n}";
}
}