unregister_meta_key( string $object_type, string $meta_key, string $object_subtype = '' ): bool
- Since
- 4.6.0, 4.9.8
- Source
wp-includes/meta.php:1661
Compatibility
- WordPress
- since 4.9.8
- 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
$object_typestring- Type of object metadata is for. Accepts 'blog', 'post', 'comment', 'term', 'user', or any other object type with an associated meta table.
$meta_keystring- Metadata key.
$object_subtypestringoptional- The subtype of the object type. Default empty string.Default:
''
Return value
bool- True if successful. False if the meta key was not registered.
Performance profile
How much work a call to unregister_meta_key() does, and what it touches: the algorithmic scaling, the Zend instruction count per call across PHP versions, the hooks it hands control to, and the core code that calls it. Measured from the compiled opcodes, not a stopwatch, so every number is identical on any machine running the same PHP version, and every function in core is ranked by cost.
- Cost class
- Trivial
- Scaling
- Constant
- Instructions
- 11–69
- Plugin surface
- None
- Called by
- 2
Touches nothing outside its own arguments.
No loop in the body: the same number of instructions runs whatever you pass in.
Executed per call on PHP 8.5, depending on the branch taken. The body compiles to 90.
Nothing here hands control to plugin code.
2 places in core call this, so the cost is paid more often than your own code shows.
What one call costs · 7 distinct outcomes
One number would be a lie: the work depends on which branch runs. These are every distinct cost unregister_meta_key() can have, taken from its control-flow graph on PHP 8.5.
| When | Instructions | Calls it makes |
|---|---|---|
| always | 11–29 | registered_meta_key_exists() |
registered_meta_key_exists() && !is_callable() | 31–34 | registered_meta_key_exists(), is_callable() |
registered_meta_key_exists() && isset($args) && !is_callable() | 36–39 | registered_meta_key_exists(), is_callable(), is_callable() |
registered_meta_key_exists() && is_callable() | 43–49 | registered_meta_key_exists(), is_callable(), remove_filter() |
registered_meta_key_exists() && isset($args) | 48–54 | registered_meta_key_exists(), is_callable(), is_callable(), remove_filter() |
registered_meta_key_exists() && isset($args) | 48–54 | registered_meta_key_exists(), is_callable(), remove_filter(), is_callable() |
registered_meta_key_exists() && isset($args) && is_callable() | 60–69 | registered_meta_key_exists(), is_callable(), remove_filter(), is_callable(), remove_filter() |
Across PHP versions
Compiles the same on PHP 7.4, 8.1, 8.2, 8.3, 8.4, 8.5 and 8.6-dev: 90 instructions, 11–69 executed per call, 9 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.
Uses · 2
- registered_meta_key_exists()Checks if a meta key is registered.
- remove_filter()Removes a callback function from a filter hook.
Used by · 2
- unregister_post_meta()Unregisters a meta key for posts.
- unregister_term_meta()Unregisters a meta key for terms.
Source code
function unregister_meta_key( $object_type, $meta_key, $object_subtype = '' ) { global $wp_meta_keys; if ( ! registered_meta_key_exists( $object_type, $meta_key, $object_subtype ) ) { return false; } $args = $wp_meta_keys[ $object_type ][ $object_subtype ][ $meta_key ]; if ( isset( $args['sanitize_callback'] ) && is_callable( $args['sanitize_callback'] ) ) { if ( ! empty( $object_subtype ) ) { remove_filter( "sanitize_{$object_type}_meta_{$meta_key}_for_{$object_subtype}", $args['sanitize_callback'] ); } else { remove_filter( "sanitize_{$object_type}_meta_{$meta_key}", $args['sanitize_callback'] ); } } if ( isset( $args['auth_callback'] ) && is_callable( $args['auth_callback'] ) ) { if ( ! empty( $object_subtype ) ) { remove_filter( "auth_{$object_type}_meta_{$meta_key}_for_{$object_subtype}", $args['auth_callback'] ); } else { remove_filter( "auth_{$object_type}_meta_{$meta_key}", $args['auth_callback'] ); } } unset( $wp_meta_keys[ $object_type ][ $object_subtype ][ $meta_key ] ); // Do some clean up. if ( empty( $wp_meta_keys[ $object_type ][ $object_subtype ] ) ) { unset( $wp_meta_keys[ $object_type ][ $object_subtype ] ); } if ( empty( $wp_meta_keys[ $object_type ] ) ) { unset( $wp_meta_keys[ $object_type ] ); } return true;}Changelog
Introduced in 4.6.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
$object_subtype parameter was added.from the docblockAbout this page
- Parsed data
- Generated from the wordpress-develop 7.1.0 tag, from
src/wp-includes/meta.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.