WP_Locale_Switcher::change_locale( string $locale )
- Since
- 4.7.0
- Source
wp-includes/class-wp-locale-switcher.php:280
Description
Loads the translations, changes the global $wp_locale object and updates all post type labels.
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
$localestring- The locale to change to.
Performance profile
How much work a call to WP_Locale_Switcher::change_locale() does, and what it touches: the algorithmic scaling, the Zend instruction count per call across PHP versions, the hooks it hands control to, and the core code that calls it. Measured from the compiled opcodes, not a stopwatch, so every number is identical on any machine running the same PHP version, and every function in core is ranked by cost.
- Cost class
- Trivial
- Scaling
- Constant
- Instructions
- 21–23
- Plugin surface
- 1 hook
- Called by
- 2
Touches nothing outside its own arguments.
No loop in the body: the same number of instructions runs whatever you pass in.
Executed per call on PHP 8.5, depending on the branch taken. The body compiles to 23.
Third-party callbacks on 'change_locale' run inside this call, and their cost is not bounded by anything here.
2 places in core call this, so the cost is paid more often than your own code shows.
What it touches
- hookthird-party callbacks
do_action()called directly
What one call costs · 2 distinct outcomes
One number would be a lie: the work depends on which branch runs. These are every distinct cost WP_Locale_Switcher::change_locale() can have, taken from its control-flow graph on PHP 8.5.
| When | Instructions | Calls it makes |
|---|---|---|
!($phpmailer instanceof) | 21 | ->load_translations(), ::WP_Translation_Controller(), ->set_locale(), do_action() |
$phpmailer instanceof | 23 | ->load_translations(), ::WP_Translation_Controller(), ->set_locale(), ->SetLanguage(), do_action() |
Across PHP versions
Compiles the same on PHP 7.4, 8.1, 8.2, 8.3, 8.4, 8.5 and 8.6-dev: 23 instructions, 21–23 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 WP_Locale_Switcher::change_locale() runs, in this order:
- do_action( change_locale )actionline 300 (+20 into the body)
Fires when the locale is switched to or restored.
Uses · 5
- do_action()Calls the callback functions that have been added to an action hook.
- WP_Locale_Switcher::load_translations()Load translations for a given locale.
- WP_Locale::__construct()Constructor which calls helper methods to set up object variables.
- WP_Translation_Controller::get_instance()::set_locale()
- WP_Translation_Controller::get_instance()Utility method to retrieve the main instance of the class.
Used by · 2
- WP_Locale_Switcher::restore_previous_locale()Restores the translations according to the previous locale.
- WP_Locale_Switcher::switch_to_locale()Switches the translations according to the given locale.
Source code
private function change_locale( $locale ) { global $wp_locale, $phpmailer; $this->load_translations( $locale ); $wp_locale = new WP_Locale(); WP_Translation_Controller::get_instance()->set_locale( $locale ); if ( $phpmailer instanceof WP_PHPMailer ) { $phpmailer->SetLanguage(); } /** * Fires when the locale is switched to or restored. * * @since 4.7.0 * * @param string $locale The new locale. */ do_action( 'change_locale', $locale ); }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 6.8.8 tag, from
src/wp-includes/class-wp-locale-switcher.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.