描述:
通过页面id获取所有子页面
用法:
<?php get_page_children( $page_id, $pages ) ?>
参数:
$page_id
(integer) (必填) 页面ID.
默认值: None
$pages
(array) (必填) 页面对象列表。
默认值: None
示例:
<?php
// Set up the objects needed
$my_wp_query = new WP_Query();
$all_wp_pages = $my_wp_query->query(array('post_type' => 'page'));
// Get the page as an Object
$portfolio = get_page_by_title('Portfolio');
// Filter through all pages and find Portfolio's children
$portfolio_children = get_page_children( $portfolio->ID, $all_wp_pages );
// echo what we get back from WP to the browser
echo '<pre>' . print_r( $portfolio_children, true ) . '</pre>';
?>
源文件:
/**
* Identify descendants of a given page ID in a list of page objects.
*
* Descendants are identified from the `$pages` array passed to the function. No database queries are performed.
*
* @since 1.5.1
*
* @param int $page_id Page ID.
* @param array $pages List of page objects from which descendants should be identified.
* @return array List of page children.
*/
function get_page_children( $page_id, $pages ) {
// Build a hash of ID -> children.
$children = array();
foreach ( (array) $pages as $page ) {
$children[ intval( $page->post_parent ) ][] = $page;
}
$page_list = array();
// Start the search by looking at immediate children.
if ( isset( $children[ $page_id ] ) ) {
// Always start at the end of the stack in order to preserve original `$pages` order.
$to_look = array_reverse( $children[ $page_id ] );
while ( $to_look ) {
$p = array_pop( $to_look );
$page_list[] = $p;
if ( isset( $children[ $p->ID ] ) ) {
foreach ( array_reverse( $children[ $p->ID ] ) as $child ) {
// Append to the `$to_look` stack to descend the tree.
$to_look[] = $child;
}
}
}
}
return $page_list;
}