get_theme_root( string $stylesheet_or_template = '' ): string
- Since
- 1.5.0
- Source
wp-includes/theme.php:600
Description
Does not have trailing slash.
Compatibility
- WordPress
- since 1.5.0
- 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
$stylesheet_or_templatestringoptional- The stylesheet or template name of the theme.
Default is to leverage the main theme root.Default:''
Return value
string- Themes directory path.
Performance profile
How much work a call to get_theme_root() 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
- Moderate
- Scaling
- Constant
- Instructions
- 10–25
- Plugin surface
- 1 hook
- Called by
- 13
Reads stored settings via get_option(), cached per request but not free on a cold cache.
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 25.
Third-party callbacks on 'theme_root' run inside this call, and their cost is not bounded by anything here.
13 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 - optionoption read or write
get_option()one call below get_theme_root()
Further down the call graph this can also reach 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 · 2 distinct outcomes
One number would be a lie: the work depends on which branch runs. These are every distinct cost get_theme_root() can have, taken from its control-flow graph on PHP 8.5.
| When | Instructions | Calls it makes |
|---|---|---|
| always | 10–13 | apply_filters() |
| always | 17–25 | get_raw_theme_root(), apply_filters() |
Across PHP versions
| PHP | Compiled | Executed | Branches | Notes |
|---|---|---|---|---|
| 8.6-dev | 25 | 10–25 | 4 | |
| 8.5 | 25 | 10–25 | 4 | |
| 8.4 | 25 | 10–25 | 4 | 3 fewer instructions than PHP 8.3 |
| 8.3 | 28 | 10–28 | 4 | |
| 8.2 | 28 | 10–28 | 4 | |
| 8.1 | 28 | 10–28 | 4 | |
| 7.4 | 28 | 10–28 | 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.
Hooks and filters fired · 1
One hook fires while get_theme_root() runs, in this order:
- apply_filters( theme_root )filterline 629 (+29 into the body)
Filters the absolute path to the themes directory.
Uses · 2
- get_raw_theme_root()Gets the raw theme root relative to the content directory with no filters applied.
- apply_filters()Calls the callback functions that have been added to a filter hook.
Used by · 13
- Theme_Upgrader::bulk_upgrade()Upgrades several themes at once.
- Theme_Upgrader::check_parent_theme_filter()Checks if a child theme is being installed and its parent also needs to be installed.
- Theme_Upgrader::install()Install a theme package.
- Theme_Upgrader::upgrade()Upgrades a theme.
- WP_Automatic_Updater::update()Updates an item, if appropriate.
- WP_Debug_Data::get_sizes()Fetches the sizes of the WordPress directories: `wordpress` (ABSPATH), `plugins`, `themes`, and `uploads`.
- WP_Debug_Data::get_wp_filesystem()Gets the file system section of the debug data.
- WP_Debug_Data::get_wp_paths_sizes()Gets the WordPress paths and sizes section of the debug data.
- WP_Filesystem_Base::wp_themes_dir()Returns the path on the remote filesystem of the Themes Directory.
- WP_Upgrader::fs_connect()Connects to the filesystem.
- _load_script_textdomain_from_src()Resolves and loads the translation JSON file for a given script or script module source URL.
- get_stylesheet_directory()Retrieves stylesheet directory path for the active theme.
Show all 13
- get_template_directory()Retrieves template directory path for the active theme.
Source code
function get_theme_root( $stylesheet_or_template = '' ) { global $wp_theme_directories; $theme_root = ''; if ( $stylesheet_or_template ) { $theme_root = get_raw_theme_root( $stylesheet_or_template ); if ( $theme_root ) { /* * Always prepend WP_CONTENT_DIR unless the root currently registered as a theme directory. * This gives relative theme roots the benefit of the doubt when things go haywire. */ if ( ! in_array( $theme_root, (array) $wp_theme_directories, true ) ) { $theme_root = WP_CONTENT_DIR . $theme_root; } } } if ( ! $theme_root ) { $theme_root = WP_CONTENT_DIR . '/themes'; } /** * Filters the absolute path to the themes directory. * * @since 1.5.0 * * @param string $theme_root Absolute path to themes directory. */ return apply_filters( 'theme_root', $theme_root );}Changelog
Introduced in 1.5.0. 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 7.0.4 tag, from
src/wp-includes/theme.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.