WordPress函数wp_check_for_changed_slugs()用法 判断文章别名是否已修改

描述：

判断文章/页面的别名是否已经修改

用法：

<?php wp_check_for_changed_slugs( $post_id ); ?>

参数：

$post_id

(integer) (必填) 文章ID.

默认值: None

源文件：

/**
* Check for changed slugs for published post objects and save the old slug.
*
* The function is used when a post object of any type is updated,
* by comparing the current and previous post objects.
*
* If the slug was changed and not already part of the old slugs then it will be
* added to the post meta field ('_wp_old_slug') for storing old slugs for that
* post.
*
* The most logically usage of this function is redirecting changed post objects, so
* that those that linked to an changed post will be redirected to the new post.
*
* @since 2.1.0
*
* @param int $post_id Post ID.
* @param WP_Post $post The Post Object
* @param WP_Post $post_before The Previous Post Object
*/
function wp_check_for_changed_slugs( $post_id, $post, $post_before ) {
// Don't bother if it hasnt changed.
if ( $post->post_name == $post_before->post_name )
return;

// We're only concerned with published, non-hierarchical objects.
if ( $post->post_status != 'publish' || is_post_type_hierarchical( $post->post_type ) )
return;

$old_slugs = (array) get_post_meta($post_id, '_wp_old_slug');

// If we haven't added this old slug before, add it now.
if ( !empty( $post_before->post_name ) && !in_array($post_before->post_name, $old_slugs) )
add_post_meta($post_id, '_wp_old_slug', $post_before->post_name);

// If the new slug was used previously, delete it from the list.
if ( in_array($post->post_name, $old_slugs) )
delete_post_meta($post_id, '_wp_old_slug', $post->post_name);
}