WordPress获取文章子元素函数：get_children

WordPress函数get_children可用于获取文章下的附件、子页面，通常我用来获取文章缩略图。

get_children( array $args = '', constant $output = OBJECT )

函数参数

$args

数组或字符串值

get_children()函数$args参数默认的值如下：

$defaults = array(
'numberposts' => -1,
'post_type' => 'any',
'post_status' => 'any',
'post_parent' => 0,
);

get_children()函数$args参数可用的值如下：

numberposts

整数型，默认值：-1

指定返回信息的数量，默认不限制

post_parent

整数型，默认值：0

父元素的ID，指定一个文章ID，将返回该文章下的子元素

post_type

字符串值，默认值：any

指定文章类型，例如：attachment、page、revision，默认所有类型

post_status

字符串值，默认值：any

文章状态，例如：publish、draft、inherit

post_mime_type

字符串值，默认为空

指定文件的MIME类型，例如：image、video、video/mp4，在返回指定格式的附件时特别有用

函数返回值

Array (
[240] => WP_Post Object (
[ID] => 240
[post_author] => 1
[post_date] => 2014-07-25 09:27:19
[post_date_gmt] => 2014-07-25 01:27:19
[post_content] =>
[post_title] => baiduseo
[post_excerpt] =>
[post_status] => inherit
[comment_status] => open
[ping_status] => closed
[post_password] =>
[post_name] => baiduseo
[to_ping] =>
[pinged] =>
[post_modified] => 2014-07-25 09:27:19
[post_modified_gmt] => 2014-07-25 01:27:19
[post_content_filtered] =>
[post_parent] => 239
[guid] => http://localhost/wp-content/uploads/2014/07/baiduseo.jpg
[menu_order] => 0
[post_type] => attachment
[post_mime_type] => image/jpeg
[comment_count] => 0
[filter] => raw )
)

函数使用示例

返回ID为239的文章下的所有图片：

$images = get_children( 'post_parent=239&post_type=attachment&post_mime_type=image' );

获取文章第一张图片的缩略图：

<?php
function echo_first_image( $postID ) {
$args = array(
'numberposts' => 1,
'order' => 'ASC',
'post_mime_type' => 'image',
'post_parent' => $postID,
'post_status' => null,
'post_type' => 'attachment',
);
$attachments = get_children( $args );
if ( $attachments ) {
foreach ( $attachments as $attachment ) {
echo '<img src="' . wp_get_attachment_thumb_url( $attachment->ID ) . '" class="current">';
}
}
}
?>

扩展阅读

get_children()函数位于：wp-includes/post.php

相关函数：

• wp_get_attachment_link()
• get_page_children()