Source
File: wp-includes/post.php
function wp_unique_post_slug( $slug, $post_ID, $post_status, $post_type, $post_parent ) {
if ( in_array( $post_status, array( 'draft', 'pending', 'auto-draft' ), true )
|| ( 'inherit' === $post_status && 'revision' === $post_type ) || 'user_request' === $post_type
) {
return $slug;
}
/**
* Filters the post slug before it is generated to be unique.
*
* Returning a non-null value will short-circuit the
* unique slug generation, returning the passed value instead.
*
* @since 5.1.0
*
* @param string|null $override_slug Short-circuit return value.
* @param string $slug The desired slug (post_name).
* @param int $post_ID Post ID.
* @param string $post_status The post status.
* @param string $post_type Post type.
* @param int $post_parent Post parent ID.
*/
$override_slug = apply_filters( 'pre_wp_unique_post_slug', null, $slug, $post_ID, $post_status, $post_type, $post_parent );
if ( null !== $override_slug ) {
return $override_slug;
}
global $wpdb, $wp_rewrite;
$original_slug = $slug;
$feeds = $wp_rewrite->feeds;
if ( ! is_array( $feeds ) ) {
$feeds = array();
}
if ( 'attachment' === $post_type ) {
// Attachment slugs must be unique across all types.
$check_sql = "SELECT post_name FROM $wpdb->posts WHERE post_name = %s AND ID != %d LIMIT 1";
$post_name_check = $wpdb->get_var( $wpdb->prepare( $check_sql, $slug, $post_ID ) );
/**
* Filters whether the post slug would make a bad attachment slug.
*
* @since 3.1.0
*
* @param bool $bad_slug Whether the slug would be bad as an attachment slug.
* @param string $slug The post slug.
*/
$is_bad_attachment_slug = apply_filters( 'wp_unique_post_slug_is_bad_attachment_slug', false, $slug );
if ( $post_name_check
|| in_array( $slug, $feeds, true ) || 'embed' === $slug
|| $is_bad_attachment_slug
) {
$suffix = 2;
do {
$alt_post_name = _truncate_post_slug( $slug, 200 - ( strlen( $suffix ) + 1 ) ) . "-$suffix";
$post_name_check = $wpdb->get_var( $wpdb->prepare( $check_sql, $alt_post_name, $post_ID ) );
$suffix++;
} while ( $post_name_check );
$slug = $alt_post_name;
}
} elseif ( is_post_type_hierarchical( $post_type ) ) {
if ( 'nav_menu_item' === $post_type ) {
return $slug;
}
/*
* Page slugs must be unique within their own trees. Pages are in a separate
* namespace than posts so page slugs are allowed to overlap post slugs.
*/
$check_sql = "SELECT post_name FROM $wpdb->posts WHERE post_name = %s AND post_type IN ( %s, 'attachment' ) AND ID != %d AND post_parent = %d LIMIT 1";
$post_name_check = $wpdb->get_var( $wpdb->prepare( $check_sql, $slug, $post_type, $post_ID, $post_parent ) );
/**
* Filters whether the post slug would make a bad hierarchical post slug.
*
* @since 3.1.0
*
* @param bool $bad_slug Whether the post slug would be bad in a hierarchical post context.
* @param string $slug The post slug.
* @param string $post_type Post type.
* @param int $post_parent Post parent ID.
*/
$is_bad_hierarchical_slug = apply_filters( 'wp_unique_post_slug_is_bad_hierarchical_slug', false, $slug, $post_type, $post_parent );
if ( $post_name_check
|| in_array( $slug, $feeds, true ) || 'embed' === $slug
|| preg_match( "@^($wp_rewrite->pagination_base)?\d+$@", $slug )
|| $is_bad_hierarchical_slug
) {
$suffix = 2;
do {
$alt_post_name = _truncate_post_slug( $slug, 200 - ( strlen( $suffix ) + 1 ) ) . "-$suffix";
$post_name_check = $wpdb->get_var( $wpdb->prepare( $check_sql, $alt_post_name, $post_type, $post_ID, $post_parent ) );
$suffix++;
} while ( $post_name_check );
$slug = $alt_post_name;
}
} else {
// Post slugs must be unique across all posts.
$check_sql = "SELECT post_name FROM $wpdb->posts WHERE post_name = %s AND post_type = %s AND ID != %d LIMIT 1";
$post_name_check = $wpdb->get_var( $wpdb->prepare( $check_sql, $slug, $post_type, $post_ID ) );
$post = get_post( $post_ID );
// Prevent new post slugs that could result in URLs that conflict with date archives.
$conflicts_with_date_archive = false;
if ( 'post' === $post_type && ( ! $post || $post->post_name !== $slug ) && preg_match( '/^[0-9]+$/', $slug ) ) {
$slug_num = intval( $slug );
if ( $slug_num ) {
$permastructs = array_values( array_filter( explode( '/', get_option( 'permalink_structure' ) ) ) );
$postname_index = array_search( '%postname%', $permastructs, true );
/*
* Potential date clashes are as follows:
*
* - Any integer in the first permastruct position could be a year.
* - An integer between 1 and 12 that follows 'year' conflicts with 'monthnum'.
* - An integer between 1 and 31 that follows 'monthnum' conflicts with 'day'.
*/
if ( 0 === $postname_index ||
( $postname_index && '%year%' === $permastructs[ $postname_index - 1 ] && 13 > $slug_num ) ||
( $postname_index && '%monthnum%' === $permastructs[ $postname_index - 1 ] && 32 > $slug_num )
) {
$conflicts_with_date_archive = true;
}
}
}
/**
* Filters whether the post slug would be bad as a flat slug.
*
* @since 3.1.0
*
* @param bool $bad_slug Whether the post slug would be bad as a flat slug.
* @param string $slug The post slug.
* @param string $post_type Post type.
*/
$is_bad_flat_slug = apply_filters( 'wp_unique_post_slug_is_bad_flat_slug', false, $slug, $post_type );
if ( $post_name_check
|| in_array( $slug, $feeds, true ) || 'embed' === $slug
|| $conflicts_with_date_archive
|| $is_bad_flat_slug
) {
$suffix = 2;
do {
$alt_post_name = _truncate_post_slug( $slug, 200 - ( strlen( $suffix ) + 1 ) ) . "-$suffix";
$post_name_check = $wpdb->get_var( $wpdb->prepare( $check_sql, $alt_post_name, $post_type, $post_ID ) );
$suffix++;
} while ( $post_name_check );
$slug = $alt_post_name;
}
}
/**
* Filters the unique post slug.
*
* @since 3.3.0
*
* @param string $slug The post slug.
* @param int $post_ID Post ID.
* @param string $post_status The post status.
* @param string $post_type Post type.
* @param int $post_parent Post parent ID
* @param string $original_slug The original post slug.
*/
return apply_filters( 'wp_unique_post_slug', $slug, $post_ID, $post_status, $post_type, $post_parent, $original_slug );
}