4 * Null index field - means search engine does not implement this field.
6 class NullIndexField
implements SearchIndexField
{
9 * Get mapping for specific search engine
10 * @param SearchEngine $engine
11 * @return array|null Null means this field does not map to anything
13 public function getMapping( SearchEngine
$engine ) {
18 * Set global flag for this field.
20 * @param int $flag Bit flag to set/unset
21 * @param bool $unset True if flag should be unset, false by default
24 public function setFlag( $flag, $unset = false ) {
28 * Check if flag is set.
30 * @return int 0 if unset, !=0 if set
32 public function checkFlag( $flag ) {
37 * Merge two field definitions if possible.
39 * @param SearchIndexField $that
40 * @return SearchIndexField|false New definition or false if not mergeable.
42 public function merge( SearchIndexField
$that ) {