implements search on null/notnull metadata

Signed-off-by: Maxence Lange <maxence@artificial-owl.com>

Author: ArtificialOwl

apps/dav/lib/Files/FileSearchBackend.php

@@ -39,6 +39,7 @@
 use OCP\Files\Folder;
 use OCP\Files\IRootFolder;
 use OCP\Files\Node;
+use OCP\Files\Search\ISearchComparison;
 use OCP\Files\Search\ISearchOperator;
 use OCP\Files\Search\ISearchOrder;
 use OCP\Files\Search\ISearchQuery;
@@ -367,22 +368,30 @@ private function transformSearchOperation(Operator $operator) {
 				if (count($operator->arguments) !== 2) {
 					throw new \InvalidArgumentException('Invalid number of arguments for ' . $trimmedType . ' operation');
 				}
-				if (!($operator->arguments[0] instanceof SearchPropertyDefinition)) {
-					throw new \InvalidArgumentException('Invalid argument 1 for ' . $trimmedType . ' operation, expected property');
-				}
 				if (!($operator->arguments[1] instanceof Literal)) {
 					throw new \InvalidArgumentException('Invalid argument 2 for ' . $trimmedType . ' operation, expected literal');
 				}
-
+				$value = $operator->arguments[1]->value;
+			case Operator::OPERATION_IS_DEFINED:
+				if (!($operator->arguments[0] instanceof SearchPropertyDefinition)) {
+					throw new \InvalidArgumentException('Invalid argument 1 for ' . $trimmedType . ' operation, expected property');
+				}
 				$property = $operator->arguments[0];
-				$value = $this->castValue($property, $operator->arguments[1]->value);
+
 				if (str_starts_with($property->name, FilesPlugin::FILE_METADATA_PREFIX)) {
-					return new SearchComparison($trimmedType, substr($property->name, strlen(FilesPlugin::FILE_METADATA_PREFIX)), $value, IMetadataQuery::EXTRA);
+					$field = substr($property->name, strlen(FilesPlugin::FILE_METADATA_PREFIX));
+					$extra = IMetadataQuery::EXTRA;
 				} else {
-					return new SearchComparison($trimmedType, $this->mapPropertyNameToColumn($property), $value);
+					$field = $this->mapPropertyNameToColumn($property);
 				}
 
-				// no break
+				return new SearchComparison(
+					ISearchComparison::COMPARE_DEFINED,
+					$field,
+					$this->castValue($property, $value ?? ''),
+					$extra ?? ''
+				);
+
 			case Operator::OPERATION_IS_COLLECTION:
 				return new SearchComparison('eq', 'mimetype', ICacheEntry::DIRECTORY_MIMETYPE);
 			default:
@@ -416,7 +425,11 @@ private function mapPropertyNameToColumn(SearchPropertyDefinition $property) {
 	}
 
 	private function castValue(SearchPropertyDefinition $property, $value) {
-		switch ($property->dataType) {
+		if ($value === '') {
+			return '';
+		}
+
+ 		switch ($property->dataType) {
 			case SearchPropertyDefinition::DATATYPE_BOOLEAN:
 				return $value === 'yes';
 			case SearchPropertyDefinition::DATATYPE_DECIMAL:

lib/private/Files/Cache/SearchBuilder.php

@@ -47,6 +47,7 @@ class SearchBuilder {
 		ISearchComparison::COMPARE_GREATER_THAN_EQUAL => 'gte',
 		ISearchComparison::COMPARE_LESS_THAN => 'lt',
 		ISearchComparison::COMPARE_LESS_THAN_EQUAL => 'lte',
+		ISearchComparison::COMPARE_DEFINED => 'isNotNull',
 	];
 
 	protected static $searchOperatorNegativeMap = [
@@ -57,6 +58,7 @@ class SearchBuilder {
 		ISearchComparison::COMPARE_GREATER_THAN_EQUAL => 'lt',
 		ISearchComparison::COMPARE_LESS_THAN => 'gte',
 		ISearchComparison::COMPARE_LESS_THAN_EQUAL => 'gt',
+		ISearchComparison::COMPARE_DEFINED => 'isNull',
 	];
 
 	public const TAG_FAVORITE = '_$!<Favorite>!$_';

lib/public/Files/Search/ISearchComparison.php

@@ -35,6 +35,7 @@ interface ISearchComparison extends ISearchOperator {
 	public const COMPARE_LESS_THAN_EQUAL = 'lte';
 	public const COMPARE_LIKE = 'like';
 	public const COMPARE_LIKE_CASE_SENSITIVE = 'clike';
+	public const COMPARE_DEFINED = 'defined';
 
 	public const HINT_PATH_EQ_HASH = 'path_eq_hash'; // transform `path = "$path"` into `path_hash = md5("$path")`, on by default