WP_Locale_Switcher::restore_previous_locale(): string|false
- Since
- 4.7.0
- Source
wp-includes/class-wp-locale-switcher.php:123
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.
Return value
string|false- Locale on success, false on failure.
Performance profile
How much work a call to WP_Locale_Switcher::restore_previous_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
- 8–31
- Plugin surface
- 1 hook
- Called by
- 1
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 33.
Third-party callbacks on 'restore_previous_locale' run inside this call, and their cost is not bounded by anything here.
1 place 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::restore_previous_locale() can have, taken from its control-flow graph on PHP 8.5.
| When | Instructions | Calls it makes |
|---|---|---|
$previous_locale === null | 8 | array_pop() |
$previous_locale !== null | 28–31 | array_pop(), end(), ->change_locale(), do_action() |
Across PHP versions
| PHP | Compiled | Executed | Branches | Notes |
|---|---|---|---|---|
| 8.6-dev | 33 | 8–31 | 3 | |
| 8.5 | 33 | 8–31 | 3 | |
| 8.4 | 33 | 8–31 | 3 | |
| 8.3 | 33 | 8–31 | 3 | |
| 8.2 | 33 | 8–31 | 3 | |
| 8.1 | 33 | 8–31 | 3 | 1 fewer instruction than PHP 7.4 |
| 7.4 | 34 | 8–32 | 3 |
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::restore_previous_locale() runs, in this order:
- do_action( restore_previous_locale )actionline 149 (+26 into the body)
Fires when the locale is restored to the previous one.
Uses · 2
- do_action()Calls the callback functions that have been added to an action hook.
- WP_Locale_Switcher::change_locale()Changes the site's locale to the given one.
Used by · 1
- WP_Locale_Switcher::restore_current_locale()Restores the translations according to the original locale.
Source code
public function restore_previous_locale() { $previous_locale = array_pop( $this->stack ); if ( null === $previous_locale ) { // The stack is empty, bail. return false; } $entry = end( $this->stack ); $locale = is_array( $entry ) ? $entry[0] : false; if ( ! $locale ) { // There's nothing left in the stack: go back to the original locale. $locale = $this->original_locale; } $this->change_locale( $locale ); /** * Fires when the locale is restored to the previous one. * * @since 4.7.0 * * @param string $locale The new locale. * @param string $previous_locale The previous locale. */ do_action( 'restore_previous_locale', $locale, $previous_locale[0] ); return $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 7.0.4 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.