WordPress/wp-includes/meta.php

862 lines
25 KiB
PHP

<?php
/**
* Metadata API
*
* Functions for retrieving and manipulating metadata of various WordPress object types. Metadata
* for an object is a represented by a simple key-value pair. Objects may contain multiple
* metadata entries that share the same key and differ only in their value.
*
* @package WordPress
* @subpackage Meta
* @since 2.9.0
*/
/**
* Add metadata for the specified object.
*
* @since 2.9.0
* @uses $wpdb WordPress database object for queries.
* @uses do_action() Calls 'added_{$meta_type}_meta' with meta_id of added metadata entry,
* object ID, meta key, and meta value
*
* @param string $meta_type Type of object metadata is for (e.g., comment, post, or user)
* @param int $object_id ID of the object metadata is for
* @param string $meta_key Metadata key
* @param string $meta_value Metadata value
* @param bool $unique Optional, default is false. Whether the specified metadata key should be
* unique for the object. If true, and the object already has a value for the specified
* metadata key, no change will be made
* @return bool The meta ID on successful update, false on failure.
*/
function add_metadata($meta_type, $object_id, $meta_key, $meta_value, $unique = false) {
if ( !$meta_type || !$meta_key )
return false;
if ( !$object_id = absint($object_id) )
return false;
if ( ! $table = _get_meta_table($meta_type) )
return false;
global $wpdb;
$column = esc_sql($meta_type . '_id');
// expected_slashed ($meta_key)
$meta_key = stripslashes($meta_key);
$meta_value = stripslashes_deep($meta_value);
$meta_value = sanitize_meta( $meta_key, $meta_value, $meta_type );
$check = apply_filters( "add_{$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( $meta_value );
do_action( "add_{$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, $meta_type . '_meta');
do_action( "added_{$meta_type}_meta", $mid, $object_id, $meta_key, $_meta_value );
return $mid;
}
/**
* Update metadata for the specified object. If no value already exists for the specified object
* ID and metadata key, the metadata will be added.
*
* @since 2.9.0
* @uses $wpdb WordPress database object for queries.
* @uses do_action() Calls 'update_{$meta_type}_meta' before updating metadata with meta_id of
* metadata entry to update, object ID, meta key, and meta value
* @uses do_action() Calls 'updated_{$meta_type}_meta' after updating metadata with meta_id of
* updated metadata entry, object ID, meta key, and meta value
*
* @param string $meta_type Type of object metadata is for (e.g., comment, post, or user)
* @param int $object_id ID of the object metadata is for
* @param string $meta_key Metadata key
* @param string $meta_value Metadata value
* @param string $prev_value Optional. If specified, only update existing metadata entries with
* the specified value. Otherwise, update all entries.
* @return bool True on successful update, false on failure.
*/
function update_metadata($meta_type, $object_id, $meta_key, $meta_value, $prev_value = '') {
if ( !$meta_type || !$meta_key )
return false;
if ( !$object_id = absint($object_id) )
return false;
if ( ! $table = _get_meta_table($meta_type) )
return false;
global $wpdb;
$column = esc_sql($meta_type . '_id');
$id_column = 'user' == $meta_type ? 'umeta_id' : 'meta_id';
// expected_slashed ($meta_key)
$meta_key = stripslashes($meta_key);
$meta_value = stripslashes_deep($meta_value);
$meta_value = sanitize_meta( $meta_key, $meta_value, $meta_type );
$check = apply_filters( "update_{$meta_type}_metadata", null, $object_id, $meta_key, $meta_value, $prev_value );
if ( null !== $check )
return (bool) $check;
if ( ! $meta_id = $wpdb->get_var( $wpdb->prepare( "SELECT $id_column FROM $table WHERE meta_key = %s AND $column = %d", $meta_key, $object_id ) ) )
return add_metadata($meta_type, $object_id, $meta_key, $meta_value);
// Compare existing value to new value if no prev value given and the key exists only once.
if ( empty($prev_value) ) {
$old_value = get_metadata($meta_type, $object_id, $meta_key);
if ( count($old_value) == 1 ) {
if ( $old_value[0] === $meta_value )
return false;
}
}
$_meta_value = $meta_value;
$meta_value = maybe_serialize( $meta_value );
$data = compact( 'meta_value' );
$where = array( $column => $object_id, 'meta_key' => $meta_key );
if ( !empty( $prev_value ) ) {
$prev_value = maybe_serialize($prev_value);
$where['meta_value'] = $prev_value;
}
do_action( "update_{$meta_type}_meta", $meta_id, $object_id, $meta_key, $_meta_value );
if ( 'post' == $meta_type )
do_action( 'update_postmeta', $meta_id, $object_id, $meta_key, $meta_value );
$wpdb->update( $table, $data, $where );
wp_cache_delete($object_id, $meta_type . '_meta');
do_action( "updated_{$meta_type}_meta", $meta_id, $object_id, $meta_key, $_meta_value );
if ( 'post' == $meta_type )
do_action( 'updated_postmeta', $meta_id, $object_id, $meta_key, $meta_value );
return true;
}
/**
* Delete metadata for the specified object.
*
* @since 2.9.0
* @uses $wpdb WordPress database object for queries.
* @uses do_action() Calls 'deleted_{$meta_type}_meta' after deleting with meta_id of
* deleted metadata entries, object ID, meta key, and meta value
*
* @param string $meta_type Type of object metadata is for (e.g., comment, post, or user)
* @param int $object_id ID of the object metadata is for
* @param string $meta_key Metadata key
* @param string $meta_value Optional. Metadata value. If specified, only delete metadata entries
* with this value. Otherwise, delete all entries with the specified meta_key.
* @param bool $delete_all Optional, default is false. If true, delete matching metadata entries
* for all objects, ignoring the specified object_id. Otherwise, only delete matching
* metadata entries for the specified object_id.
* @return bool True on successful delete, false on failure.
*/
function delete_metadata($meta_type, $object_id, $meta_key, $meta_value = '', $delete_all = false) {
if ( !$meta_type || !$meta_key )
return false;
if ( (!$object_id = absint($object_id)) && !$delete_all )
return false;
if ( ! $table = _get_meta_table($meta_type) )
return false;
global $wpdb;
$type_column = esc_sql($meta_type . '_id');
$id_column = 'user' == $meta_type ? 'umeta_id' : 'meta_id';
// expected_slashed ($meta_key)
$meta_key = stripslashes($meta_key);
$meta_value = stripslashes_deep($meta_value);
$check = apply_filters( "delete_{$meta_type}_metadata", null, $object_id, $meta_key, $meta_value, $delete_all );
if ( null !== $check )
return (bool) $check;
$_meta_value = $meta_value;
$meta_value = maybe_serialize( $meta_value );
$query = $wpdb->prepare( "SELECT $id_column FROM $table WHERE meta_key = %s", $meta_key );
if ( !$delete_all )
$query .= $wpdb->prepare(" AND $type_column = %d", $object_id );
if ( $meta_value )
$query .= $wpdb->prepare(" AND meta_value = %s", $meta_value );
$meta_ids = $wpdb->get_col( $query );
if ( !count( $meta_ids ) )
return false;
if ( $delete_all )
$object_ids = $wpdb->get_col( $wpdb->prepare( "SELECT $type_column FROM $table WHERE meta_key = %s", $meta_key ) );
do_action( "delete_{$meta_type}_meta", $meta_ids, $object_id, $meta_key, $_meta_value );
if ( 'post' == $meta_type )
do_action( 'delete_postmeta', $meta_ids );
$query = "DELETE FROM $table WHERE $id_column IN( " . implode( ',', $meta_ids ) . " )";
$count = $wpdb->query($query);
if ( !$count )
return false;
if ( $delete_all ) {
foreach ( (array) $object_ids as $o_id ) {
wp_cache_delete($o_id, $meta_type . '_meta');
}
} else {
wp_cache_delete($object_id, $meta_type . '_meta');
}
do_action( "deleted_{$meta_type}_meta", $meta_ids, $object_id, $meta_key, $_meta_value );
if ( 'post' == $meta_type )
do_action( 'deleted_postmeta', $meta_ids );
return true;
}
/**
* Retrieve metadata for the specified object.
*
* @since 2.9.0
*
* @param string $meta_type Type of object metadata is for (e.g., comment, post, or user)
* @param int $object_id ID of the object metadata is for
* @param string $meta_key Optional. Metadata key. If not specified, retrieve all metadata for
* the specified object.
* @param bool $single Optional, default is false. If true, return only the first value of the
* specified meta_key. This parameter has no effect if meta_key is not specified.
* @return string|array Single metadata value, or array of values
*/
function get_metadata($meta_type, $object_id, $meta_key = '', $single = false) {
if ( !$meta_type )
return false;
if ( !$object_id = absint($object_id) )
return false;
$check = apply_filters( "get_{$meta_type}_metadata", null, $object_id, $meta_key, $single );
if ( null !== $check ) {
if ( $single && is_array( $check ) )
return $check[0];
else
return $check;
}
$meta_cache = wp_cache_get($object_id, $meta_type . '_meta');
if ( !$meta_cache ) {
$meta_cache = update_meta_cache( $meta_type, array( $object_id ) );
$meta_cache = $meta_cache[$object_id];
}
if ( !$meta_key )
return $meta_cache;
if ( isset($meta_cache[$meta_key]) ) {
if ( $single )
return maybe_unserialize( $meta_cache[$meta_key][0] );
else
return array_map('maybe_unserialize', $meta_cache[$meta_key]);
}
if ($single)
return '';
else
return array();
}
/**
* Determine if a meta key is set for a given object
*
* @since 3.3.0
*
* @param string $meta_type Type of object metadata is for (e.g., comment, post, or user)
* @param int $object_id ID of the object metadata is for
* @param string $meta_key Metadata key.
* @return boolean true of the key is set, false if not.
*/
function metadata_exists( $meta_type, $object_id, $meta_key ) {
if ( ! $meta_type )
return false;
if ( ! $object_id = absint( $object_id ) )
return false;
$check = apply_filters( "get_{$meta_type}_metadata", null, $object_id, $meta_key, true );
if ( null !== $check )
return true;
$meta_cache = wp_cache_get( $object_id, $meta_type . '_meta' );
if ( !$meta_cache ) {
$meta_cache = update_meta_cache( $meta_type, array( $object_id ) );
$meta_cache = $meta_cache[$object_id];
}
if ( isset( $meta_cache[ $meta_key ] ) )
return true;
return false;
}
/**
* Get meta data by meta ID
*
* @since 3.3.0
*
* @param string $meta_type Type of object metadata is for (e.g., comment, post, or user)
* @param int $meta_id ID for a specific meta row
* @return object Meta object or false.
*/
function get_metadata_by_mid( $meta_type, $meta_id ) {
global $wpdb;
if ( ! $meta_type )
return false;
if ( !$meta_id = absint( $meta_id ) )
return false;
if ( ! $table = _get_meta_table($meta_type) )
return false;
$id_column = ( 'user' == $meta_type ) ? 'umeta_id' : 'meta_id';
$meta = $wpdb->get_row( $wpdb->prepare( "SELECT * FROM $table WHERE $id_column = %d", $meta_id ) );
if ( empty( $meta ) )
return false;
if ( isset( $meta->meta_value ) )
$meta->meta_value = maybe_unserialize( $meta->meta_value );
return $meta;
}
/**
* Update meta data by meta ID
*
* @since 3.3.0
*
* @uses get_metadata_by_mid() Calls get_metadata_by_mid() to fetch the meta key, value
* and object_id of the given meta_id.
*
* @param string $meta_type Type of object metadata is for (e.g., comment, post, or user)
* @param int $meta_id ID for a specific meta row
* @param string $meta_value Metadata value
* @param string $meta_key Optional, you can provide a meta key to update it
* @return bool True on successful update, false on failure.
*/
function update_metadata_by_mid( $meta_type, $meta_id, $meta_value, $meta_key = false ) {
global $wpdb;
// Make sure everything is valid.
if ( ! $meta_type )
return false;
if ( ! $meta_id = absint( $meta_id ) )
return false;
if ( ! $table = _get_meta_table( $meta_type ) )
return false;
$column = esc_sql($meta_type . '_id');
$id_column = 'user' == $meta_type ? 'umeta_id' : 'meta_id';
// Fetch the meta and go on if it's found.
if ( $meta = get_metadata_by_mid( $meta_type, $meta_id ) ) {
$original_key = $meta->meta_key;
$original_value = $meta->meta_value;
$object_id = $meta->{$column};
// If a new meta_key (last parameter) was specified, change the meta key,
// otherwise use the original key in the update statement.
if ( false === $meta_key ) {
$meta_key = $original_key;
} elseif ( ! is_string( $meta_key ) ) {
return false;
}
// Sanitize the meta
$_meta_value = $meta_value;
$meta_value = sanitize_meta( $meta_key, $meta_value, $meta_type );
$meta_value = maybe_serialize( $meta_value );
// Format the data query arguments.
$data = array(
'meta_key' => $meta_key,
'meta_value' => $meta_value
);
// Format the where query arguments.
$where = array();
$where[$id_column] = $meta_id;
do_action( "update_{$meta_type}_meta", $meta_id, $object_id, $meta_key, $_meta_value );
if ( 'post' == $meta_type )
do_action( 'update_postmeta', $meta_id, $object_id, $meta_key, $meta_value );
// Run the update query, all fields in $data are %s, $where is a %d.
$result = (bool) $wpdb->update( $table, $data, $where, '%s', '%d' );
// Clear the caches.
wp_cache_delete($object_id, $meta_type . '_meta');
do_action( "updated_{$meta_type}_meta", $meta_id, $object_id, $meta_key, $_meta_value );
if ( 'post' == $meta_type )
do_action( 'updated_postmeta', $meta_id, $object_id, $meta_key, $meta_value );
return $result;
}
// And if the meta was not found.
return false;
}
/**
* Delete meta data by meta ID
*
* @since 3.3.0
*
* @uses get_metadata_by_mid() Calls get_metadata_by_mid() to fetch the meta key, value
* and object_id of the given meta_id.
*
* @param string $meta_type Type of object metadata is for (e.g., comment, post, or user)
* @param int $meta_id ID for a specific meta row
* @return bool True on successful delete, false on failure.
*/
function delete_metadata_by_mid( $meta_type, $meta_id ) {
global $wpdb;
// Make sure everything is valid.
if ( ! $meta_type )
return false;
if ( ! $meta_id = absint( $meta_id ) )
return false;
if ( ! $table = _get_meta_table( $meta_type ) )
return false;
// object and id columns
$column = esc_sql($meta_type . '_id');
$id_column = 'user' == $meta_type ? 'umeta_id' : 'meta_id';
// Fetch the meta and go on if it's found.
if ( $meta = get_metadata_by_mid( $meta_type, $meta_id ) ) {
$object_id = $meta->{$column};
do_action( "delete_{$meta_type}_meta", (array) $meta_id, $object_id, $meta->meta_key, $meta->meta_value );
if ( 'post' == $meta_type )
do_action( 'delete_postmeta', $object_id );
// Run the query, will return true if deleted, false otherwise
$result = (bool) $wpdb->query( $wpdb->prepare( "DELETE FROM $table WHERE $id_column = %d LIMIT 1;", $meta_id ) );
// Clear the caches.
wp_cache_delete($object_id, $meta_type . '_meta');
do_action( "deleted_{$meta_type}_meta", (array) $meta_id, $object_id, $meta->meta_key, $meta->meta_value );
if ( 'post' == $meta_type )
do_action( 'delete_postmeta', $object_id );
return $result;
}
// Meta id was not found.
return false;
}
/**
* Update the metadata cache for the specified objects.
*
* @since 2.9.0
* @uses $wpdb WordPress database object for queries.
*
* @param string $meta_type Type of object metadata is for (e.g., comment, post, or user)
* @param int|array $object_ids array or comma delimited list of object IDs to update cache for
* @return mixed Metadata cache for the specified objects, or false on failure.
*/
function update_meta_cache($meta_type, $object_ids) {
if ( empty( $meta_type ) || empty( $object_ids ) )
return false;
if ( ! $table = _get_meta_table($meta_type) )
return false;
$column = esc_sql($meta_type . '_id');
global $wpdb;
if ( !is_array($object_ids) ) {
$object_ids = preg_replace('|[^0-9,]|', '', $object_ids);
$object_ids = explode(',', $object_ids);
}
$object_ids = array_map('intval', $object_ids);
$cache_key = $meta_type . '_meta';
$ids = array();
$cache = array();
foreach ( $object_ids as $id ) {
$cached_object = wp_cache_get( $id, $cache_key );
if ( false === $cached_object )
$ids[] = $id;
else
$cache[$id] = $cached_object;
}
if ( empty( $ids ) )
return $cache;
// Get meta info
$id_list = join(',', $ids);
$meta_list = $wpdb->get_results( $wpdb->prepare("SELECT $column, meta_key, meta_value FROM $table WHERE $column IN ($id_list)",
$meta_type), ARRAY_A );
if ( !empty($meta_list) ) {
foreach ( $meta_list as $metarow) {
$mpid = intval($metarow[$column]);
$mkey = $metarow['meta_key'];
$mval = $metarow['meta_value'];
// Force subkeys to be array type:
if ( !isset($cache[$mpid]) || !is_array($cache[$mpid]) )
$cache[$mpid] = array();
if ( !isset($cache[$mpid][$mkey]) || !is_array($cache[$mpid][$mkey]) )
$cache[$mpid][$mkey] = array();
// Add a value to the current pid/key:
$cache[$mpid][$mkey][] = $mval;
}
}
foreach ( $ids as $id ) {
if ( ! isset($cache[$id]) )
$cache[$id] = array();
wp_cache_add( $id, $cache[$id], $cache_key );
}
return $cache;
}
/**
* Given a meta query, generates SQL clauses to be appended to a main query
*
* @since 3.2.0
*
* @see WP_Meta_Query
*
* @param array $meta_query A meta query
* @param string $type Type of meta
* @param string $primary_table
* @param string $primary_id_column
* @param object $context (optional) The main query object
* @return array( 'join' => $join_sql, 'where' => $where_sql )
*/
function get_meta_sql( $meta_query, $type, $primary_table, $primary_id_column, $context = null ) {
$meta_query_obj = new WP_Meta_Query( $meta_query );
return $meta_query_obj->get_sql( $type, $primary_table, $primary_id_column, $context );
}
/**
* Container class for a multiple metadata query
*
* @since 3.2.0
*/
class WP_Meta_Query {
/**
* List of metadata queries. A single query is an associative array:
* - 'key' string The meta key
* - 'value' string|array The meta value
* - 'compare' (optional) string How to compare the key to the value.
* Possible values: '=', '!=', '>', '>=', '<', '<=', 'LIKE', 'NOT LIKE', 'IN', 'NOT IN', 'BETWEEN', 'NOT BETWEEN'.
* Default: '='
* - 'type' string (optional) The type of the value.
* Possible values: 'NUMERIC', 'BINARY', 'CHAR', 'DATE', 'DATETIME', 'DECIMAL', 'SIGNED', 'TIME', 'UNSIGNED'.
* Default: 'CHAR'
*
* @since 3.2.0
* @access public
* @var array
*/
public $queries = array();
/**
* The relation between the queries. Can be one of 'AND' or 'OR'.
*
* @since 3.2.0
* @access public
* @var string
*/
public $relation;
/**
* Constructor
*
* @param array $meta_query (optional) A meta query
*/
function __construct( $meta_query = false ) {
if ( !$meta_query )
return;
if ( isset( $meta_query['relation'] ) && strtoupper( $meta_query['relation'] ) == 'OR' ) {
$this->relation = 'OR';
} else {
$this->relation = 'AND';
}
$this->queries = array();
foreach ( $meta_query as $key => $query ) {
if ( ! is_array( $query ) )
continue;
$this->queries[] = $query;
}
}
/**
* Constructs a meta query based on 'meta_*' query vars
*
* @since 3.2.0
* @access public
*
* @param array $qv The query variables
*/
function parse_query_vars( $qv ) {
$meta_query = array();
// Simple query needs to be first for orderby=meta_value to work correctly
foreach ( array( 'key', 'compare', 'type' ) as $key ) {
if ( !empty( $qv[ "meta_$key" ] ) )
$meta_query[0][ $key ] = $qv[ "meta_$key" ];
}
// WP_Query sets 'meta_value' = '' by default
if ( isset( $qv[ 'meta_value' ] ) && '' !== $qv[ 'meta_value' ] )
$meta_query[0]['value'] = $qv[ 'meta_value' ];
if ( !empty( $qv['meta_query'] ) && is_array( $qv['meta_query'] ) ) {
$meta_query = array_merge( $meta_query, $qv['meta_query'] );
}
$this->__construct( $meta_query );
}
/**
* Generates SQL clauses to be appended to a main query.
*
* @since 3.2.0
* @access public
*
* @param string $type Type of meta
* @param string $primary_table
* @param string $primary_id_column
* @param object $context (optional) The main query object
* @return array( 'join' => $join_sql, 'where' => $where_sql )
*/
function get_sql( $type, $primary_table, $primary_id_column, $context = null ) {
global $wpdb;
if ( ! $meta_table = _get_meta_table( $type ) )
return false;
$meta_id_column = esc_sql( $type . '_id' );
$join = array();
$where = array();
foreach ( $this->queries as $k => $q ) {
$meta_key = isset( $q['key'] ) ? trim( $q['key'] ) : '';
$meta_compare = isset( $q['compare'] ) ? strtoupper( $q['compare'] ) : '=';
$meta_type = isset( $q['type'] ) ? strtoupper( $q['type'] ) : 'CHAR';
if ( ! in_array( $meta_compare, array( '=', '!=', '>', '>=', '<', '<=', 'LIKE', 'NOT LIKE', 'IN', 'NOT IN', 'BETWEEN', 'NOT BETWEEN' ) ) )
$meta_compare = '=';
if ( 'NUMERIC' == $meta_type )
$meta_type = 'SIGNED';
elseif ( ! in_array( $meta_type, array( 'BINARY', 'CHAR', 'DATE', 'DATETIME', 'DECIMAL', 'SIGNED', 'TIME', 'UNSIGNED' ) ) )
$meta_type = 'CHAR';
$i = count( $join );
$alias = $i ? 'mt' . $i : $meta_table;
// Set JOIN
$join[$i] = "INNER JOIN $meta_table";
$join[$i] .= $i ? " AS $alias" : '';
$join[$i] .= " ON ($primary_table.$primary_id_column = $alias.$meta_id_column)";
$where[$k] = '';
if ( !empty( $meta_key ) )
$where[$k] = $wpdb->prepare( "$alias.meta_key = %s", $meta_key );
if ( !isset( $q['value'] ) ) {
if ( empty( $where[$k] ) )
unset( $join[$i] );
continue;
}
$meta_value = $q['value'];
if ( in_array( $meta_compare, array( 'IN', 'NOT IN', 'BETWEEN', 'NOT BETWEEN' ) ) ) {
if ( ! is_array( $meta_value ) )
$meta_value = preg_split( '/[,\s]+/', $meta_value );
if ( empty( $meta_value ) ) {
unset( $join[$i] );
continue;
}
} else {
$meta_value = trim( $meta_value );
}
if ( 'IN' == substr( $meta_compare, -2) ) {
$meta_compare_string = '(' . substr( str_repeat( ',%s', count( $meta_value ) ), 1 ) . ')';
} elseif ( 'BETWEEN' == substr( $meta_compare, -7) ) {
$meta_value = array_slice( $meta_value, 0, 2 );
$meta_compare_string = '%s AND %s';
} elseif ( 'LIKE' == substr( $meta_compare, -4 ) ) {
$meta_value = '%' . like_escape( $meta_value ) . '%';
$meta_compare_string = '%s';
} else {
$meta_compare_string = '%s';
}
if ( ! empty( $where[$k] ) )
$where[$k] .= ' AND ';
$where[$k] = ' (' . $where[$k] . $wpdb->prepare( "CAST($alias.meta_value AS {$meta_type}) {$meta_compare} {$meta_compare_string})", $meta_value );
}
$where = array_filter( $where );
if ( empty( $where ) )
$where = '';
else
$where = ' AND (' . implode( "\n{$this->relation} ", $where ) . ' )';
$join = implode( "\n", $join );
if ( ! empty( $join ) )
$join = ' ' . $join;
return apply_filters_ref_array( 'get_meta_sql', array( compact( 'join', 'where' ), $this->queries, $type, $primary_table, $primary_id_column, $context ) );
}
}
/**
* Retrieve the name of the metadata table for the specified object type.
*
* @since 2.9.0
* @uses $wpdb WordPress database object for queries.
*
* @param string $type Type of object to get metadata table for (e.g., comment, post, or user)
* @return mixed Metadata table name, or false if no metadata table exists
*/
function _get_meta_table($type) {
global $wpdb;
$table_name = $type . 'meta';
if ( empty($wpdb->$table_name) )
return false;
return $wpdb->$table_name;
}
/**
* Determine whether a meta key is protected
*
* @since 3.1.3
*
* @param string $meta_key Meta key
* @return bool True if the key is protected, false otherwise.
*/
function is_protected_meta( $meta_key, $meta_type = null ) {
$protected = ( '_' == $meta_key[0] );
return apply_filters( 'is_protected_meta', $protected, $meta_key, $meta_type );
}
/**
* Sanitize meta value
*
* @since 3.1.3
*
* @param string $meta_key Meta key
* @param mixed $meta_value Meta value to sanitize
* @param string $meta_type Type of meta
* @return mixed Sanitized $meta_value
*/
function sanitize_meta( $meta_key, $meta_value, $meta_type ) {
return apply_filters( "sanitize_{$meta_type}_meta_{$meta_key}", $meta_value, $meta_key, $meta_type );
}
/**
* Register meta key
*
* @since 3.3.0
*
* @param string $meta_type Type of meta
* @param string $meta_key Meta key
* @param string|array $sanitize_callback A function or method to call when sanitizing the value of $meta_key.
* @param string|array $auth_callback Optional. A function or method to call when performing edit_post_meta, add_post_meta, and delete_post_meta capability checks.
* @param array $args Arguments
*/
function register_meta( $meta_type, $meta_key, $sanitize_callback, $auth_callback = null ) {
if ( is_callable( $sanitize_callback ) )
add_filter( "sanitize_{$meta_type}_meta_{$meta_key}", $sanitize_callback, 10, 3 );
if ( empty( $auth_callback ) ) {
if ( is_protected_meta( $meta_key, $meta_type ) )
$auth_callback = '__return_false';
else
$auth_callback = '__return_true';
}
if ( is_callable( $auth_callback ) )
add_filter( "auth_{$meta_type}_meta_{$meta_key}", $auth_callback, 10, 6 );
}
?>