+ * @param string $field The field to query against: 'id', 'slug', 'email' or 'login'
+ * @param string|int $value The field value
+ * @return object|false Raw user object
+ */
+ public static function get_data_by( $field, $value ) {
+ global $wpdb;
+
+ if ( 'id' == $field ) {
+ // Make sure the value is numeric to avoid casting objects, for example,
+ // to int 1.
+ if ( ! is_numeric( $value ) )
+ return false;
+ $value = intval( $value );
+ if ( $value < 1 )
+ return false;
+ } else {
+ $value = trim( $value );
+ }
+
+ if ( !$value )
+ return false;
+
+ switch ( $field ) {
+ case 'id':
+ $user_id = $value;
+ $db_field = 'ID';
+ break;
+ case 'slug':
+ $user_id = wp_cache_get($value, 'userslugs');
+ $db_field = 'user_nicename';
+ break;
+ case 'email':
+ $user_id = wp_cache_get($value, 'useremail');
+ $db_field = 'user_email';
+ break;
+ case 'login':
+ $value = sanitize_user( $value );
+ $user_id = wp_cache_get($value, 'userlogins');
+ $db_field = 'user_login';
+ break;
+ default:
+ return false;
+ }
+
+ if ( false !== $user_id ) {
+ if ( $user = wp_cache_get( $user_id, 'users' ) )
+ return $user;
+ }
+
+ if ( !$user = $wpdb->get_row( $wpdb->prepare(
+ "SELECT * FROM $wpdb->users WHERE $db_field = %s", $value
+ ) ) )
+ return false;
+
+ update_user_caches( $user );
+
+ return $user;
+ }
+
+ /**
+ * Magic method for checking the existence of a certain custom field