get_metadata_default( string $meta_type, int $object_id, string $meta_key, bool $single = false ): mixed
- Since
- 5.5.0
- Source
wp-includes/meta.php:688
Description
By default, an empty string is returned if $single is true, or an empty array if it's false.
Compatibility
- WordPress
- since 5.5.0
- 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
$meta_typestring- Type of object metadata is for. Accepts 'post', 'comment', 'term', 'user', or any other object type with an associated meta table.
$object_idint- ID of the object metadata is for.
$meta_keystring- Metadata key.
$singlebooloptional- If true, return only the first value of the specified
$meta_key.
This parameter has no effect if$meta_keyis not specified. Default false.Default:false
Return value
mixed- An array of default values if
$singleis false.
The default value of the meta field if$singleis true.
Performance profile
How much work a call to get_metadata_default() 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
- 20–27
- 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 28.
Third-party callbacks on 'default_{$meta_type}_metadata' run inside this call, and their cost is not bounded by anything here.
1 place in core call this, so the cost is paid more often than your own code shows.
What it touches
- hookthird-party callbacks
apply_filters()called directly
What one call costs · 2 distinct outcomes
One number would be a lie: the work depends on which branch runs. These are every distinct cost get_metadata_default() can have, taken from its control-flow graph on PHP 8.5.
| When | Instructions | Calls it makes |
|---|---|---|
| always | 20–21 | apply_filters() |
| always | 24–27 | apply_filters(), wp_is_numeric_array() |
Across PHP versions
Compiles the same on PHP 7.4, 8.1, 8.2, 8.3, 8.4, 8.5 and 8.6-dev: 28 instructions, 20–27 executed per call, 3 branches. The work does not change between versions.
An instruction is not a fixed amount of time, so a matching count is not necessarily the same speed; what it rules out is a difference in the work itself.
Hooks and filters fired · 1
One hook fires while get_metadata_default() runs, in this order:
- apply_filters( default_{$meta_type}_metadata )filterline 718 (+30 into the body)
Filters the default metadata value for a specified meta key and object.
Uses · 2
- apply_filters()Calls the callback functions that have been added to a filter hook.
- wp_is_numeric_array()Determines if the variable is a numeric-indexed array.
Used by · 1
- get_metadata()Retrieves the value of a metadata field for the specified object type and ID.
Source code
function get_metadata_default( $meta_type, $object_id, $meta_key, $single = false ) { if ( $single ) { $value = ''; } else { $value = array(); } /** * Filters the default metadata value for a specified meta key and object. * * The dynamic portion of the hook name, `$meta_type`, refers to the meta object type * (post, comment, term, user, or any other type with an associated meta table). * * Possible filter names include: * * - `default_post_metadata` * - `default_comment_metadata` * - `default_term_metadata` * - `default_user_metadata` * * @since 5.5.0 * * @param mixed $value The value to return, either a single metadata value or an array * of values depending on the value of `$single`. * @param int $object_id ID of the object metadata is for. * @param string $meta_key Metadata key. * @param bool $single Whether to return only the first value of the specified `$meta_key`. * @param string $meta_type Type of object metadata is for. Accepts 'post', 'comment', 'term', 'user', * or any other object type with an associated meta table. */ $value = apply_filters( "default_{$meta_type}_metadata", $value, $object_id, $meta_key, $single, $meta_type ); if ( ! $single && ! wp_is_numeric_array( $value ) ) { $value = array( $value ); } return $value;}Changelog
Introduced in 5.5.0. 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 6.7.7 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.