wxr_authors_list( int[] $post_ids = null )
- Since
- 3.1.0
- Source
wp-admin/includes/export.php:406
Compatibility
- WordPress
- since 3.1.0
- PHP
- 7.4–8.6-dev
- 6.7.7
- 6.8.8
- 6.9.7
- 7.0.4
- 7.1.0
Present in every tracked release (6.7.7 to 7.1.0), and compiles on PHP 7.4 through 8.6-dev.
Parameters
$post_idsint[]optional- Array of post IDs to filter the query by.Default:
null
Performance profile
How much work a call to wxr_authors_list() does, and what it touches: the algorithmic scaling, the Zend instruction count per call across PHP versions, the hooks it hands control to, and the core code that calls it. Measured from the compiled opcodes, not a stopwatch, so every number is identical on any machine running the same PHP version, and every function in core is ranked by cost.
- Cost class
- Heavy
- Scaling
- Scales with input
- Instructions
- 20–32
- Plugin surface
- None
- Called by
- 1
Reaches the database via get_user_by().
The body loops, so the work grows with what you pass in.
Executed per call on PHP 8.5, depending on the branch taken. The body compiles to 111.
Nothing here hands control to plugin code.
1 place in core call this, so the cost is paid more often than your own code shows.
What it touches
- querycontent query
get_user_by()one call below wxr_authors_list()
Further down the call graph this can also reach hook, option, cache, serialize and transient. Those are the worst case, several calls deep and usually down an error path, not what a normal call pays.
What one call costs · 2 distinct outcomes
One number would be a lie: the work depends on which branch runs. These are every distinct cost wxr_authors_list() can have, taken from its control-flow graph on PHP 8.5.
| When | Instructions | Calls it makes |
|---|---|---|
empty($post_ids) | 20–22 | array_filter(), array_unique() |
!empty($post_ids) | 30–32 | array_map(), array_chunk(), array_filter(), array_unique() |
Across PHP versions
| PHP | Compiled | Executed | Branches | Notes |
|---|---|---|---|---|
| 8.6-dev | 111 | 20–32 | 8 | |
| 8.5 | 111 | 20–32 | 8 | |
| 8.4 | 111 | 20–32 | 8 | 3 fewer instructions than PHP 8.3 |
| 8.3 | 114 | 20–32 | 8 | |
| 8.2 | 114 | 20–32 | 8 | |
| 8.1 | 114 | 20–32 | 8 | 1 fewer instruction than PHP 7.4 |
| 7.4 | 115 | 20–32 | 8 |
An instruction is not a fixed amount of time, so a matching count is not necessarily the same speed; what it rules out is a difference in the work itself.
Uses · 2
- get_userdata()Retrieves user info by user ID.
- wxr_cdata()Wraps given string in XML CDATA tag.
Used by · 1
- export_wp()Generates the WXR export file for download.
Source code
function wxr_authors_list( ?array $post_ids = null ) { global $wpdb; if ( ! empty( $post_ids ) ) { $post_ids = array_map( 'absint', $post_ids ); $post_id_chunks = array_chunk( $post_ids, 20 ); } else { $post_id_chunks = array( array() ); } $authors = array(); foreach ( $post_id_chunks as $next_posts ) { $and = ! empty( $next_posts ) ? 'AND ID IN (' . implode( ', ', $next_posts ) . ')' : ''; $results = $wpdb->get_results( "SELECT DISTINCT post_author FROM $wpdb->posts WHERE post_status != 'auto-draft' $and" ); foreach ( (array) $results as $result ) { $authors[] = get_userdata( $result->post_author ); } } $authors = array_filter( $authors ); $authors = array_unique( $authors, SORT_REGULAR ); // Remove duplicate authors. foreach ( $authors as $author ) { echo "\t<wp:author>"; echo '<wp:author_id>' . (int) $author->ID . '</wp:author_id>'; echo '<wp:author_login>' . wxr_cdata( $author->user_login ) . '</wp:author_login>'; echo '<wp:author_email>' . wxr_cdata( $author->user_email ) . '</wp:author_email>'; echo '<wp:author_display_name>' . wxr_cdata( $author->display_name ) . '</wp:author_display_name>'; echo '<wp:author_first_name>' . wxr_cdata( $author->first_name ) . '</wp:author_first_name>'; echo '<wp:author_last_name>' . wxr_cdata( $author->last_name ) . '</wp:author_last_name>'; echo "</wp:author>\n"; } }Changelog
Introduced in 3.1.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
About this page
- Parsed data
- Generated from the wordpress-develop 6.9.7 tag, from
src/wp-admin/includes/export.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it. - Corrections
- Something wrong on this page? Report it and it gets fixed in the next regeneration.