get_parent_theme_file_uri( string $file = '' ): string
- Since
- 4.7.0
- Source
wp-includes/link-template.php:4679
Compatibility
- WordPress
- since 4.7.0
- 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
$filestringoptional- File to return the URL for in the template directory.Default:
''
Return value
string- The URL of the file.
Performance profile
How much work a call to get_parent_theme_file_uri() 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
- Trivial
- Scaling
- Constant
- Instructions
- 18
- Plugin surface
- 1 hook
- Called by
- 4
Touches nothing outside its own arguments.
No loop in the body: the same number of instructions runs whatever you pass in.
Executed per call on PHP 8.5. The body compiles to 22.
Third-party callbacks on 'parent_theme_file_uri' run inside this call, and their cost is not bounded by anything here.
4 places in core call this, so the cost is paid more often than your own code shows.
What it touches
- hookthird-party callbacks
apply_filters()called directly
Further down the call graph this can also reach option, cache, serialize, transient and query. Those are the worst case, several calls deep and usually down an error path, not what a normal call pays.
What one call costs · 1 distinct outcome
One number would be a lie: the work depends on which branch runs. These are every distinct cost get_parent_theme_file_uri() can have, taken from its control-flow graph on PHP 8.5.
| When | Instructions | Calls it makes |
|---|---|---|
| always | 18 | ltrim(), get_template_directory_uri(), apply_filters() |
Across PHP versions
Compiles the same on PHP 7.4, 8.1, 8.2, 8.3, 8.4, 8.5 and 8.6-dev: 22 instructions, 18 executed per call, 1 branch. The work does not change between versions.
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.
Hooks and filters fired · 1
One hook fires while get_parent_theme_file_uri() runs, in this order:
- apply_filters( parent_theme_file_uri )filterline 4696 (+17 into the body)
Filters the URL to a file in the parent theme.
Uses · 2
- get_template_directory_uri()Retrieves template directory URI for the active theme.
- apply_filters()Calls the callback functions that have been added to a filter hook.
Used by · 4
- twentyseventeen_custom_header_setup()Sets up the WordPress core custom header feature.
- twentytwentyfive_enqueue_styles()Enqueues the theme stylesheet on the front.
- twentytwentyfour_block_stylesheets()Enqueues custom block stylesheets.
- twentytwentytwo_styles()Enqueues styles.
Source code
function get_parent_theme_file_uri( $file = '' ) { $file = ltrim( $file, '/' ); if ( empty( $file ) ) { $url = get_template_directory_uri(); } else { $url = get_template_directory_uri() . '/' . $file; } /** * Filters the URL to a file in the parent theme. * * @since 4.7.0 * * @param string $url The file URL. * @param string $file The requested file to search for. */ return apply_filters( 'parent_theme_file_uri', $url, $file );}Changelog
Introduced in 4.7.0. 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-includes/link-template.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.