wppaste
WordPress

get_theme_file_uri( string $file = '' ): string

Since
4.7.0
Source
wp-includes/link-template.php:4647
Retrieves the URL of a file in the theme.

Description

Searches in the stylesheet directory before the template directory so themes which inherit from a parent theme can just override one file.

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 search for in the stylesheet directory.Default: ''

Return value

string
The URL of the file.

Performance profile

How much work a call to get_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
Heavy

Reads or writes the filesystem via file_exists().

Scaling
Constant

No loop in the body: the same number of instructions runs whatever you pass in.

Instructions
21–32

Executed per call on PHP 8.5, depending on the branch taken. The body compiles to 40.

Plugin surface
1 hook

Third-party callbacks on 'theme_file_uri' run inside this call, and their cost is not bounded by anything here.

Called by
22

22 places in core call this, so the cost is paid more often than your own code shows.

What it touches

  • hookthird-party callbacksapply_filters()called directly
  • filesystemfilesystem accessfile_exists()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 · 4 distinct outcomes

One number would be a lie: the work depends on which branch runs. These are every distinct cost get_theme_file_uri() can have, taken from its control-flow graph on PHP 8.5.

WhenInstructionsCalls it makes
empty($file)21ltrim(), get_stylesheet_directory(), get_stylesheet_directory_uri(), apply_filters()
!empty($file) && $stylesheet_directory === false25ltrim(), get_stylesheet_directory(), get_template_directory(), get_template_directory_uri(), apply_filters()
!empty($file) && $stylesheet_directory !== false && !file_exists()31ltrim(), get_stylesheet_directory(), get_template_directory(), file_exists(), get_template_directory_uri(), apply_filters()
!empty($file) && $stylesheet_directory !== false && file_exists()32ltrim(), get_stylesheet_directory(), get_template_directory(), file_exists(), get_stylesheet_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: 40 instructions, 21–32 executed per call, 3 branches. 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_theme_file_uri() runs, in this order:

  1. apply_filters( theme_file_uri )filterline 4668 (+21 into the body)

    Filters the URL to a file in the theme.

Uses · 5

Used by · 22

Show all 22

Source code

function get_theme_file_uri( $file = '' ) {	$file = ltrim( $file, '/' ); 	$stylesheet_directory = get_stylesheet_directory(); 	if ( empty( $file ) ) {		$url = get_stylesheet_directory_uri();	} elseif ( get_template_directory() !== $stylesheet_directory && file_exists( $stylesheet_directory . '/' . $file ) ) {		$url = get_stylesheet_directory_uri() . '/' . $file;	} else {		$url = get_template_directory_uri() . '/' . $file;	} 	/**	 * Filters the URL to a file in the theme.	 *	 * @since 4.7.0	 *	 * @param string $url  The file URL.	 * @param string $file The requested file to search for.	 */	return apply_filters( 'theme_file_uri', $url, $file );}

Changelog

Introduced in 4.7.0. Unchanged from 6.7.7 through 7.1.0.

  1. 6.7.7
  2. 6.8.8
  3. 6.9.7
  4. 7.0.4
  5. 7.1.0

Signature, return type and hooks compared across 5 parsed releases.

About this page

Parsed data
Generated from the wordpress-develop 7.1.0 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.