Adds metadata for the specified object.
Parameters
$meta_type
stringrequired- Type of object metadata is for. Accepts
'post'
,'comment'
,'term'
,'user'
, or any other object type with an associated meta table. $object_id
intrequired- ID of the object metadata is for.
$meta_key
stringrequired- Metadata key.
$meta_value
mixedrequired- Metadata value. Arrays and objects are stored as serialized data and will be returned as the same type when retrieved. Other data types will be stored as strings in the database:
- false is stored and retrieved as an empty string (
''
) - true is stored and retrieved as
'1'
- numbers (both integer and float) are stored and retrieved as strings Must be serializable if non-scalar.
- false is stored and retrieved as an empty string (
$unique
booloptional- Whether the specified metadata key should be unique for the object.
If true, and the object already has a value for the specified metadata key, no change will be made.Default:
false
Source
function add_metadata( $meta_type, $object_id, $meta_key, $meta_value, $unique = false ) {
global $wpdb;
if ( ! $meta_type || ! $meta_key || ! is_numeric( $object_id ) ) {
return false;
}
$object_id = absint( $object_id );
if ( ! $object_id ) {
return false;
}
$table = _get_meta_table( $meta_type );
if ( ! $table ) {
return false;
}
$meta_subtype = get_object_subtype( $meta_type, $object_id );
$column = sanitize_key( $meta_type . '_id' );
// expected_slashed ($meta_key)
$meta_key = wp_unslash( $meta_key );
$meta_value = wp_unslash( $meta_value );
$meta_value = sanitize_meta( $meta_key, $meta_value, $meta_type, $meta_subtype );
/**
* Short-circuits adding metadata of a specific type.
*
* The dynamic portion of the hook name, `$meta_type`, refers to the meta object type
* (post, comment, term, user, or any other type with an associated meta table).
* Returning a non-null value will effectively short-circuit the function.
*
* Possible hook names include:
*
* - `add_post_metadata`
* - `add_comment_metadata`
* - `add_term_metadata`
* - `add_user_metadata`
*
* @since 3.1.0
*
* @param null|bool $check Whether to allow adding metadata for the given type.
* @param int $object_id ID of the object metadata is for.
* @param string $meta_key Metadata key.
* @param mixed $meta_value Metadata value. Must be serializable if non-scalar.
* @param bool $unique Whether the specified meta key should be unique for the object.
*/
$check = apply_filters( "add_{$meta_type}_metadata", null, $object_id, $meta_key, $meta_value, $unique );
if ( null !== $check ) {
return $check;
}
if ( $unique && $wpdb->get_var(
$wpdb->prepare(
"SELECT COUNT(*) FROM $table WHERE meta_key = %s AND $column = %d",
$meta_key,
$object_id
)
) ) {
return false;
}
$_meta_value = $meta_value;
$meta_value = maybe_serialize( $meta_value );
/**
* Fires immediately before meta of a specific type is added.
*
* The dynamic portion of the hook name, `$meta_type`, refers to the meta object type
* (post, comment, term, user, or any other type with an associated meta table).
*
* Possible hook names include:
*
* - `add_post_meta`
* - `add_comment_meta`
* - `add_term_meta`
* - `add_user_meta`
*
* @since 3.1.0
*
* @param int $object_id ID of the object metadata is for.
* @param string $meta_key Metadata key.
* @param mixed $_meta_value Metadata value.
*/
do_action( "add_{$meta_type}_meta", $object_id, $meta_key, $_meta_value );
$result = $wpdb->insert(
$table,
array(
$column => $object_id,
'meta_key' => $meta_key,
'meta_value' => $meta_value,
)
);
if ( ! $result ) {
return false;
}
$mid = (int) $wpdb->insert_id;
wp_cache_delete( $object_id, $meta_type . '_meta' );
/**
* Fires immediately after meta of a specific type is added.
*
* The dynamic portion of the hook name, `$meta_type`, refers to the meta object type
* (post, comment, term, user, or any other type with an associated meta table).
*
* Possible hook names include:
*
* - `added_post_meta`
* - `added_comment_meta`
* - `added_term_meta`
* - `added_user_meta`
*
* @since 2.9.0
*
* @param int $mid The meta ID after successful update.
* @param int $object_id ID of the object metadata is for.
* @param string $meta_key Metadata key.
* @param mixed $_meta_value Metadata value.
*/
do_action( "added_{$meta_type}_meta", $mid, $object_id, $meta_key, $_meta_value );
return $mid;
}
Hooks
- do_action( “added_{$meta_type}_meta”,
int $mid ,int $object_id ,string $meta_key ,mixed $_meta_value ) Fires immediately after meta of a specific type is added.
- do_action( “add_{$meta_type}_meta”,
int $object_id ,string $meta_key ,mixed $_meta_value ) Fires immediately before meta of a specific type is added.
- apply_filters( “add_{$meta_type}_metadata”,
null|bool $check ,int $object_id ,string $meta_key ,mixed $meta_value ,bool $unique ) Short-circuits adding metadata of a specific type.
Changelog
Version | Description |
---|---|
2.9.0 | Introduced. |
Example:
Add an additional meta value for comments. Here location is the meta key $location is the variable holds its value.