is_local_attachment( string $url ): bool
- Since
- 2.0.0
- Source
wp-includes/post.php:6521
Description
For more information on this and similar theme functions, check out the https://developer.wordpress.org/themes/basics/conditional-tags/ Conditional Tags article in the Theme Developer Handbook.
Compatibility
- WordPress
- since 2.0.0
- 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
$urlstring- URL to check
Return value
bool- True on success, false on failure.
Performance profile
How much work a call to is_local_attachment() does, and what it touches: the algorithmic scaling, the Zend instruction count per call across PHP versions, the hooks it hands control to, and the core code that calls it. Measured from the compiled opcodes, not a stopwatch, so every number is identical on any machine running the same PHP version, and every function in core is ranked by cost.
- Cost class
- Heavy
- Scaling
- Constant
- Instructions
- 6–23
- Plugin surface
- None
- Called by
- 1
Reaches the database via get_post().
No loop in the body: the same number of instructions runs whatever you pass in.
Executed per call on PHP 8.5, depending on the branch taken. The body compiles to 26.
Nothing here hands control to plugin code.
1 place in core call this, so the cost is paid more often than your own code shows.
What it touches
- querycontent query
get_post()called directly - hookthird-party callbacks
apply_filters()one call below is_local_attachment() - optionoption read or write
get_option()one call below is_local_attachment()
Further down the call graph this can also reach cache, serialize and transient. Those are the worst case, several calls deep and usually down an error path, not what a normal call pays.
What one call costs · 4 distinct outcomes
One number would be a lie: the work depends on which branch runs. These are every distinct cost is_local_attachment() can have, taken from its control-flow graph on PHP 8.5.
| When | Instructions | Calls it makes |
|---|---|---|
!$url | 6 | home_url() |
$url | 11 | home_url(), home_url() |
| always | 16 | home_url(), home_url(), url_to_postid() |
| always | 23 | home_url(), home_url(), url_to_postid(), get_post() |
Across PHP versions
| PHP | Compiled | Executed | Branches | Notes |
|---|---|---|---|---|
| 8.6-dev | 26 | 6–23 | 4 | |
| 8.5 | 26 | 6–23 | 4 | |
| 8.4 | 26 | 6–23 | 4 | 6 fewer instructions than PHP 8.3 |
| 8.3 | 32 | 9–29 | 4 | |
| 8.2 | 32 | 9–29 | 4 | |
| 8.1 | 32 | 9–29 | 4 | |
| 7.4 | 32 | 9–29 | 4 |
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 · 4
- str_contains()Polyfill for `str_contains()` function added in PHP 8.0.
- home_url()Retrieves the URL for the current site where the front end is accessible.
- url_to_postid()Examines a URL and try to determine the post ID it represents.
- get_post()Retrieves post data given a post ID or post object.
Used by · 1
- pingback()Pings back the links found in a post.
Source code
function is_local_attachment( $url ) { if ( ! str_contains( $url, home_url() ) ) { return false; } if ( str_contains( $url, home_url( '/?attachment_id=' ) ) ) { return true; } $id = url_to_postid( $url ); if ( $id ) { $post = get_post( $id ); if ( 'attachment' === $post->post_type ) { return true; } } return false;}Changelog
Introduced in 2.0.0. 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 6.8.8 tag, from
src/wp-includes/post.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.