diff --git a/FileProvider.podspec b/FileProvider.podspec
index 1f697fd..92ca9bc 100644
--- a/FileProvider.podspec
+++ b/FileProvider.podspec
@@ -16,7 +16,7 @@ Pod::Spec.new do |s|
   #
 
   s.name         = "FileProvider"
-  s.version      = "0.12.9"
+  s.version      = "0.14.0"
   s.summary      = "FileManager replacement for Local and Remote (WebDAV/Dropbox/OneDrive/SMB2) files on iOS and macOS."
 
   # This description is used to generate tags and improve search results.
diff --git a/FileProvider.xcodeproj/project.pbxproj b/FileProvider.xcodeproj/project.pbxproj
index ec95be0..7b022f8 100644
--- a/FileProvider.xcodeproj/project.pbxproj
+++ b/FileProvider.xcodeproj/project.pbxproj
@@ -597,7 +597,7 @@
 		799396601D48B7BF00086753 /* Debug */ = {
 			isa = XCBuildConfiguration;
 			buildSettings = {
-				BUNDLE_VERSION_STRING = 0.12.9;
+				BUNDLE_VERSION_STRING = 0.14.0;
 				CLANG_WARN_BOOL_CONVERSION = YES;
 				CLANG_WARN_CONSTANT_CONVERSION = YES;
 				CLANG_WARN_EMPTY_BODY = YES;
@@ -627,7 +627,7 @@
 		799396611D48B7BF00086753 /* Release */ = {
 			isa = XCBuildConfiguration;
 			buildSettings = {
-				BUNDLE_VERSION_STRING = 0.12.9;
+				BUNDLE_VERSION_STRING = 0.14.0;
 				CLANG_WARN_BOOL_CONVERSION = YES;
 				CLANG_WARN_CONSTANT_CONVERSION = YES;
 				CLANG_WARN_EMPTY_BODY = YES;
diff --git a/Sources/CloudFileProvider.swift b/Sources/CloudFileProvider.swift
index db30f5a..42bb0aa 100644
--- a/Sources/CloudFileProvider.swift
+++ b/Sources/CloudFileProvider.swift
@@ -9,7 +9,7 @@
 import Foundation
 
 /**
- Allows accessing to iCloud Drive stored files. Determine scope when initializing,to either access 
+ Allows accessing to iCloud Drive stored files. Determine scope when initializing, to either access
  to public documents folder or files stored as data.
  
  To setup a functional iCloud container, please
@@ -87,7 +87,7 @@ open class CloudFileProvider: LocalFileProvider {
      If the directory contains no entries or an error is occured, this method will return the empty array.
      
      - Parameter path: path to target directory. If empty, `currentPath` value will be used.
-     - Parameter completionHandler: a block with result of directory entries or error.
+     - Parameter completionHandler: a closure with result of directory entries or error.
          `contents`: An array of `FileObject` identifying the the directory entries.
          `error`: Error returned by system.
      */
@@ -156,7 +156,7 @@ open class CloudFileProvider: LocalFileProvider {
      If the directory contains no entries or an error is occured, this method will return the empty `FileObject`.
      
      - Parameter path: path to target directory. If empty, `currentPath` value will be used.
-     - Parameter completionHandler: a block with result of directory entries or error.
+     - Parameter completionHandler: a closure with result of directory entries or error.
          `attributes`: A `FileObject` containing the attributes of the item.
          `error`: Error returned by system.
      */
@@ -205,6 +205,130 @@ open class CloudFileProvider: LocalFileProvider {
         }
     }
     
+    /**
+     Search files inside directory using query asynchronously.
+     
+     - Note: For now only it's limited to file names. `query` parameter may take `NSPredicate` format in near future.
+     
+     - Parameters:
+     - path: location of directory to start search
+     - recursive: Searching subdirectories of path
+     - query: Simple string of file name to be search (for now).
+     - foundItemHandler: Closure which is called when a file is found
+     - completionHandler: Closure which will be called after finishing search. Returns an arry of `FileObject` or error if occured.
+     */
+    open override func searchFiles(path: String, recursive: Bool, query: NSPredicate, foundItemHandler: ((FileObject) -> Void)?, completionHandler: @escaping ((_ files: [FileObject], _ error: Error?) -> Void)) {
+        
+        let mapDict: [String: String] = ["url": NSMetadataItemURLKey, "name": NSMetadataItemFSNameKey, "path": NSMetadataItemPathKey, "filesize": NSMetadataItemFSSizeKey, "modifiedDate": NSMetadataItemFSContentChangeDateKey, "creationDate": NSMetadataItemFSCreationDateKey, "contentType": NSMetadataItemContentTypeKey]
+        
+        func updateQueryKeys(_ queryComponent: NSPredicate) -> NSPredicate {
+            if let cQuery = queryComponent as? NSCompoundPredicate {
+                let newSub = cQuery.subpredicates.map { updateQueryKeys($0 as! NSPredicate) }
+                switch cQuery.compoundPredicateType {
+                case .and: return NSCompoundPredicate(andPredicateWithSubpredicates: newSub)
+                case .not: return NSCompoundPredicate(notPredicateWithSubpredicate: newSub[0])
+                case .or:  return NSCompoundPredicate(orPredicateWithSubpredicates: newSub)
+                }
+            } else if let cQuery = queryComponent as? NSComparisonPredicate {
+                var newLeft = cQuery.leftExpression
+                var newRight = cQuery.rightExpression
+                if newLeft.expressionType == .keyPath, let newKey = mapDict[newLeft.keyPath] {
+                    newLeft = NSExpression(forKeyPath: newKey)
+                }
+                if newRight.expressionType == .keyPath, let newKey = mapDict[newRight.keyPath] {
+                    newRight = NSExpression(forKeyPath: newKey)
+                }
+                if newLeft.expressionType == .keyPath, newLeft.keyPath == "type" {
+                    newRight = NSExpression(forConstantValue: newRight.constantValue as? String == "directory" ? "public.directory": "public.data")
+                }
+                if newRight.expressionType == .keyPath, newRight.keyPath == "type" {
+                    newLeft = NSExpression(forConstantValue: newLeft.constantValue as? String == "directory" ? "public.directory": "public.data")
+                }
+                return NSComparisonPredicate(leftExpression: newLeft, rightExpression: newRight, modifier: cQuery.comparisonPredicateModifier, type: cQuery.predicateOperatorType, options: cQuery.options)
+            } else {
+                return queryComponent
+            }
+        }
+        
+        dispatch_queue.async {
+            let pathURL = self.url(of: path)
+            let mdquery = NSMetadataQuery()
+            mdquery.predicate = NSPredicate(format: "(%K BEGINSWITH %@) && (\(updateQueryKeys(query).predicateFormat))", NSMetadataItemPathKey, pathURL.path)
+            mdquery.searchScopes = [self.scope.rawValue]
+            
+            var lastReportedCount = 0
+            
+            if let foundItemHandler = foundItemHandler {
+                var updateObserver: NSObjectProtocol?
+                
+                // FIXME: Remove this section as it won't work as expected on iCloud
+                updateObserver = NotificationCenter.default.addObserver(forName: .NSMetadataQueryGatheringProgress, object: mdquery, queue: nil, using: { (notification) in
+                    
+                    mdquery.disableUpdates()
+                    
+                    guard mdquery.resultCount > lastReportedCount else { return }
+                    
+                    for index in lastReportedCount..<mdquery.resultCount {
+                        guard let attribs = (mdquery.result(at: index) as? NSMetadataItem)?.values(forAttributes: [NSMetadataItemURLKey, NSMetadataItemFSNameKey, NSMetadataItemPathKey, NSMetadataItemFSSizeKey, NSMetadataItemContentTypeTreeKey, NSMetadataItemFSCreationDateKey, NSMetadataItemFSContentChangeDateKey]) else {
+                            continue
+                        }
+                        
+                        guard let url = (attribs[NSMetadataItemURLKey] as? URL)?.standardized, recursive || url.deletingLastPathComponent().path.trimmingCharacters(in: pathTrimSet) == pathURL.path.trimmingCharacters(in: pathTrimSet) else {
+                            continue
+                        }
+                        
+                        if let file = self.mapFileObject(attributes: attribs) {
+                            foundItemHandler(file)
+                        }
+                    }
+                    lastReportedCount = mdquery.resultCount
+                    
+                    mdquery.enableUpdates()
+                })
+            }
+            
+            var finishObserver: NSObjectProtocol?
+            finishObserver = NotificationCenter.default.addObserver(forName: .NSMetadataQueryDidFinishGathering, object: mdquery, queue: nil, using: { (notification) in
+                defer {
+                    mdquery.stop()
+                    NotificationCenter.default.removeObserver(finishObserver!)
+                }
+                
+                guard let results = mdquery.results as? [NSMetadataItem] else {
+                    return
+                }
+                
+                mdquery.disableUpdates()
+                
+                var contents = [FileObject]()
+                for result in results {
+                    guard let attribs = result.values(forAttributes: [NSMetadataItemURLKey, NSMetadataItemFSNameKey, NSMetadataItemPathKey, NSMetadataItemFSSizeKey, NSMetadataItemContentTypeTreeKey, NSMetadataItemFSCreationDateKey, NSMetadataItemFSContentChangeDateKey]) else {
+                        continue
+                    }
+                    
+                    guard let url = (attribs[NSMetadataItemURLKey] as? URL)?.standardized, recursive || url.deletingLastPathComponent().path.trimmingCharacters(in: pathTrimSet) == pathURL.path.trimmingCharacters(in: pathTrimSet) else {
+                        continue
+                    }
+                    
+                    if let file = self.mapFileObject(attributes: attribs) {
+                        contents.append(file)
+                    }
+                }
+                self.dispatch_queue.async {
+                    completionHandler(contents, nil)
+                }
+            })
+            
+            DispatchQueue.main.async {
+                if !mdquery.start() {
+                    self.dispatch_queue.async {
+                        completionHandler([], self.throwError(path, code: CocoaError.fileReadNoPermission))
+                    }
+                }
+            }
+        }
+    }
+    
     open override func isReachable(completionHandler: @escaping (Bool) -> Void) {
         dispatch_queue.async {
             completionHandler(self.fileManager.ubiquityIdentityToken != nil)
@@ -378,7 +502,7 @@ open class CloudFileProvider: LocalFileProvider {
      
      - Parameters:
        - path: Path of file.
-       - completionHandler: a block with result of file contents or error.
+       - completionHandler: a closure with result of file contents or error.
          `contents`: contents of file in a `Data` object.
          `error`: Error returned by system.
      - Returns: An `OperationHandle` to get progress or cancel progress.
@@ -397,7 +521,7 @@ open class CloudFileProvider: LocalFileProvider {
        - path: Path of file.
        - offset: First byte index which should be read. **Starts from 0.**
        - length: Bytes count of data. Pass `-1` to read until the end of file.
-       - completionHandler: a block with result of file contents or error.
+       - completionHandler: a closure with result of file contents or error.
          `contents`: contents of file in a `Data` object.
          `error`: Error returned by system.
      - Returns: An `OperationHandle` to get progress or cancel progress.
@@ -425,98 +549,6 @@ open class CloudFileProvider: LocalFileProvider {
         return CloudOperationHandle(operationType: r.operationType, baseURL: self.baseURL)
     }
     
-    /**
-     Search files inside directory using query asynchronously.
-     
-     - Note: For now only it's limited to file names. `query` parameter may take `NSPredicate` format in near future.
-     
-     - Parameters:
-       - path: location of directory to start search
-       - recursive: Searching subdirectories of path
-       - query: Simple string of file name to be search (for now).
-       - foundItemHandler: Block which is called when a file is found
-     - completionHandler: Block which will be called after finishing search. Returns an arry of `FileObject` or error if occured.
-     */
-    open override func searchFiles(path: String, recursive: Bool, query: String, foundItemHandler: ((FileObject) -> Void)?, completionHandler: @escaping ((_ files: [FileObject], _ error: Error?) -> Void)) {
-        dispatch_queue.async {
-            let pathURL = self.url(of: path)
-            let query = NSMetadataQuery()
-            query.predicate = NSPredicate(format: "(%K BEGINSWITH %@) && (%K LIKE %@)", NSMetadataItemPathKey, pathURL.path, NSMetadataItemFSNameKey, query)
-            query.searchScopes = [self.scope.rawValue]
-            
-            var lastReportedCount = 0
-            
-            if let foundItemHandler = foundItemHandler {
-                var updateObserver: NSObjectProtocol?
-                
-                // FIXME: Remove this section as it won't work as expected on iCloud
-                updateObserver = NotificationCenter.default.addObserver(forName: .NSMetadataQueryGatheringProgress, object: query, queue: nil, using: { (notification) in
-                    
-                    query.disableUpdates()
-                    
-                    guard query.resultCount > lastReportedCount else { return }
-                    
-                    for index in lastReportedCount..<query.resultCount {
-                        guard let attribs = (query.result(at: index) as? NSMetadataItem)?.values(forAttributes: [NSMetadataItemURLKey, NSMetadataItemFSNameKey, NSMetadataItemPathKey, NSMetadataItemFSSizeKey, NSMetadataItemContentTypeTreeKey, NSMetadataItemFSCreationDateKey, NSMetadataItemFSContentChangeDateKey]) else {
-                            continue
-                        }
-                        
-                        guard let url = (attribs[NSMetadataItemURLKey] as? URL)?.standardized, recursive || url.deletingLastPathComponent().path.trimmingCharacters(in: pathTrimSet) == pathURL.path.trimmingCharacters(in: pathTrimSet) else {
-                            continue
-                        }
-                        
-                        if let file = self.mapFileObject(attributes: attribs) {
-                            foundItemHandler(file)
-                        }
-                    }
-                    lastReportedCount = query.resultCount
-                    
-                    query.enableUpdates()
-                })
-            }
-            
-            var finishObserver: NSObjectProtocol?
-            finishObserver = NotificationCenter.default.addObserver(forName: .NSMetadataQueryDidFinishGathering, object: query, queue: nil, using: { (notification) in
-                defer {
-                    query.stop()
-                    NotificationCenter.default.removeObserver(finishObserver!)
-                }
-                
-                guard let results = query.results as? [NSMetadataItem] else {
-                    return
-                }
-                
-                query.disableUpdates()
-                
-                var contents = [FileObject]()
-                for result in results {
-                    guard let attribs = result.values(forAttributes: [NSMetadataItemURLKey, NSMetadataItemFSNameKey, NSMetadataItemPathKey, NSMetadataItemFSSizeKey, NSMetadataItemContentTypeTreeKey, NSMetadataItemFSCreationDateKey, NSMetadataItemFSContentChangeDateKey]) else {
-                        continue
-                    }
-                    
-                    guard let url = (attribs[NSMetadataItemURLKey] as? URL)?.standardized, recursive || url.deletingLastPathComponent().path.trimmingCharacters(in: pathTrimSet) == pathURL.path.trimmingCharacters(in: pathTrimSet) else {
-                        continue
-                    }
-                    
-                    if let file = self.mapFileObject(attributes: attribs) {
-                        contents.append(file)
-                    }
-                }
-                self.dispatch_queue.async {
-                   completionHandler(contents, nil)
-                }
-            })
-            
-            DispatchQueue.main.async {
-                if !query.start() {
-                    self.dispatch_queue.async {
-                        completionHandler([], self.throwError(path, code: CocoaError.fileReadNoPermission))
-                    }
-                }
-            }
-        }
-    }
-    
     fileprivate var monitors = [String: (NSMetadataQuery, NSObjectProtocol)]()
     
     /**
@@ -532,7 +564,7 @@ open class CloudFileProvider: LocalFileProvider {
      
      - Parameters:
        - path: path of directory.
-       - eventHandler: Block executed after change, on a secondary thread.
+       - eventHandler: Closure executed after change, on a secondary thread.
      */
     open override func registerNotifcation(path: String, eventHandler: @escaping (() -> Void)) {
         self.unregisterNotifcation(path: path)
@@ -622,7 +654,19 @@ open class CloudFileProvider: LocalFileProvider {
         }
     }
     
-    /// Returns a pulic url with expiration date, can be shared with other people.
+    /**
+     Genrates a public url to a file to be shared with other users and can be downloaded without authentication.
+     
+     - Important: URL will be available for a limitied time, determined in `expiration` argument.
+     
+     - Parameters:
+     - to: path of file, including file/directory name.
+     - completionHandler: a closure with result of directory entries or error.
+     `link`: a url returned by Dropbox to share.
+     `attribute`: a `FileObject` containing the attributes of the item.
+     `expiration`: a `Date` object, determines when the public url will expires.
+     `error`: Error returned by Dropbox.
+     */
     open func publicLink(to path: String, completionHandler: @escaping ((_ link: URL?, _ attribute: FileObject?, _ expiration: Date?, _ error: Error?) -> Void)) {
         operation_queue.addOperation {
             do {
diff --git a/Sources/DropboxFileProvider.swift b/Sources/DropboxFileProvider.swift
index 9015150..6a56f03 100644
--- a/Sources/DropboxFileProvider.swift
+++ b/Sources/DropboxFileProvider.swift
@@ -61,7 +61,7 @@ open class DropboxFileProvider: FileProviderBasicRemote {
      The latter is easier to use and prefered. Also you can use [auth0/Lock](https://github.com/auth0/Lock.iOS-OSX) which provides graphical user interface.
      
      - Parameter credential: a `URLCredential` object with Client ID set as `user` and Token set as `password`.
-     - Parameter cache: A URLCache to cache downloaded files and contents. If set to nil, URLCache.shared object will be used.
+     - Parameter cache: A URLCache to cache downloaded files and contents.
     */
     public init(credential: URLCredential?, cache: URLCache? = nil) {
         self.baseURL = nil
@@ -135,6 +135,19 @@ open class DropboxFileProvider: FileProviderBasicRemote {
         task.resume()
     }
     
+    open func searchFiles(path: String, recursive: Bool, query: NSPredicate, foundItemHandler: ((FileObject) -> Void)?, completionHandler: @escaping ((_ files: [FileObject], _ error: Error?) -> Void)) {
+        var foundFiles = [DropboxFileObject]()
+        guard let queryStr = self.findNameQuery(query, key: "name") as? String else { return }
+        search(path, query: queryStr, foundItem: { (file) in
+            if query.evaluate(with: file.mapPredicate()) {
+                foundFiles.append(file)
+                foundItemHandler?(file)
+            }
+        }, completionHandler: { (error) in
+            completionHandler(foundFiles, error)
+        })
+    }
+    
     open func isReachable(completionHandler: @escaping (Bool) -> Void) {
         self.storageProperties { total, _ in
             completionHandler(total > 0)
@@ -145,25 +158,25 @@ open class DropboxFileProvider: FileProviderBasicRemote {
 }
 
 extension DropboxFileProvider: FileProviderOperations {
-    public func create(folder folderName: String, at atPath: String, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
+    open func create(folder folderName: String, at atPath: String, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
         let path = (atPath as NSString).appendingPathComponent(folderName) + "/"
         return doOperation(.create(path: path), completionHandler: completionHandler)
     }
     
-    public func create(file fileName: String, at path: String, contents data: Data?, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
+    open func create(file fileName: String, at path: String, contents data: Data?, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
         let filePath = (path as NSString).appendingPathComponent(fileName)
         return self.writeContents(path: filePath, contents: data ?? Data(), completionHandler: completionHandler)
     }
     
-    public func moveItem(path: String, to toPath: String, overwrite: Bool, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
+    open func moveItem(path: String, to toPath: String, overwrite: Bool, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
         return doOperation(.move(source: path, destination: toPath), completionHandler: completionHandler)
     }
     
-    public func copyItem(path: String, to toPath: String, overwrite: Bool, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
+    open func copyItem(path: String, to toPath: String, overwrite: Bool, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
         return doOperation(.copy(source: path, destination: toPath), completionHandler: completionHandler)
     }
     
-    public func removeItem(path: String, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
+    open func removeItem(path: String, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
         return doOperation(.remove(path: path), completionHandler: completionHandler)
     }
     
@@ -211,7 +224,7 @@ extension DropboxFileProvider: FileProviderOperations {
         return RemoteOperationHandle(operationType: operation, tasks: [task])
     }
     
-    public func copyItem(localFile: URL, to toPath: String, overwrite: Bool, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
+    open func copyItem(localFile: URL, to toPath: String, overwrite: Bool, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
         let opType = FileOperationType.copy(source: localFile.absoluteString, destination: toPath)
         guard fileOperationDelegate?.fileProvider(self, shouldDoOperation: opType) ?? true == true else {
             return nil
@@ -219,7 +232,7 @@ extension DropboxFileProvider: FileProviderOperations {
         return upload_simple(toPath, localFile: localFile, overwrite: overwrite, operation: opType, completionHandler: completionHandler)
     }
     
-    public func copyItem(path: String, toLocalURL destURL: URL, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
+    open func copyItem(path: String, toLocalURL destURL: URL, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
         let opType = FileOperationType.copy(source: path, destination: destURL.absoluteString)
         guard fileOperationDelegate?.fileProvider(self, shouldDoOperation: opType) ?? true == true else {
             return nil
@@ -253,7 +266,7 @@ extension DropboxFileProvider: FileProviderOperations {
 }
 
 extension DropboxFileProvider: FileProviderReadWrite {
-    public func contents(path: String, offset: Int64, length: Int, completionHandler: @escaping ((_ contents: Data?, _ error: Error?) -> Void)) -> OperationHandle? {
+    open func contents(path: String, offset: Int64, length: Int, completionHandler: @escaping ((_ contents: Data?, _ error: Error?) -> Void)) -> OperationHandle? {
         if length == 0 || offset < 0 {
             dispatch_queue.async {
                 completionHandler(Data(), nil)
@@ -295,16 +308,6 @@ extension DropboxFileProvider: FileProviderReadWrite {
         return upload_simple(path, data: data, overwrite: overwrite, operation: opType, completionHandler: completionHandler)
     }
     
-    public func searchFiles(path: String, recursive: Bool, query: String, foundItemHandler: ((FileObject) -> Void)?, completionHandler: @escaping ((_ files: [FileObject], _ error: Error?) -> Void)) {
-        var foundFiles = [DropboxFileObject]()
-        search(path, query: query, foundItem: { (file) in
-            foundFiles.append(file)
-            foundItemHandler?(file)
-            }, completionHandler: { (error) in
-                completionHandler(foundFiles, error)
-        })
-    }
-    
     /*
     fileprivate func registerNotifcation(path: String, eventHandler: (() -> Void)) {
         /* There is two ways to monitor folders changing in Dropbox. Either using webooks
@@ -346,7 +349,7 @@ extension DropboxFileProvider {
      
      - Parameters:
        - to: path of file, including file/directory name.
-       - completionHandler: a block with result of directory entries or error.
+       - completionHandler: a closure with result of directory entries or error.
          `link`: a url returned by Dropbox to share.
          `attribute`: a `FileObject` containing the attributes of the item.
          `expiration`: a `Date` object, determines when the public url will expires.
@@ -389,7 +392,7 @@ extension DropboxFileProvider {
      - Parameters:
        - remoteURL: a valid remote url to file.
        - to: Destination path of file, including file/directory name.
-       - completionHandler: a block with result of directory entries or error.
+       - completionHandler: a closure with result of directory entries or error.
          `jobId`: Job ID returned by Dropbox to monitor the copy/download progress.
          `attribute`: A `FileObject` containing the attributes of the item.
          `error`: Error returned by Dropbox.
@@ -454,7 +457,7 @@ extension DropboxFileProvider {
 }
 
 extension DropboxFileProvider: ExtendedFileProvider {
-    public func thumbnailOfFileSupported(path: String) -> Bool {
+    open func thumbnailOfFileSupported(path: String) -> Bool {
         switch (path as NSString).pathExtension.lowercased() {
         case "jpg", "jpeg", "gif", "bmp", "png", "tif", "tiff":
             return true
@@ -469,7 +472,7 @@ extension DropboxFileProvider: ExtendedFileProvider {
         }
     }
     
-    public func propertiesOfFileSupported(path: String) -> Bool {
+    open func propertiesOfFileSupported(path: String) -> Bool {
         let fileExt = (path as NSString).pathExtension.lowercased()
         switch fileExt {
         case "jpg", "jpeg", "bmp", "gif", "png", "tif", "tiff":
@@ -484,7 +487,7 @@ extension DropboxFileProvider: ExtendedFileProvider {
     }
         
     /// Default value for dimension is 64x64, according to Dropbox documentation
-    public func thumbnailOfFile(path: String, dimension: CGSize?, completionHandler: @escaping ((_ image: ImageClass?, _ error: Error?) -> Void)) {
+    open func thumbnailOfFile(path: String, dimension: CGSize?, completionHandler: @escaping ((_ image: ImageClass?, _ error: Error?) -> Void)) {
         let url: URL
         switch (path as NSString).pathExtension.lowercased() {
         case "jpg", "jpeg", "gif", "bmp", "png", "tif", "tiff":
@@ -527,7 +530,7 @@ extension DropboxFileProvider: ExtendedFileProvider {
         task.resume()
     }
     
-    public func propertiesOfFile(path: String, completionHandler: @escaping ((_ propertiesDictionary: [String : Any], _ keys: [String], _ error: Error?) -> Void)) {
+    open func propertiesOfFile(path: String, completionHandler: @escaping ((_ propertiesDictionary: [String : Any], _ keys: [String], _ error: Error?) -> Void)) {
         let url = URL(string: "files/get_metadata", relativeTo: apiURL)!
         var request = URLRequest(url: url)
         request.httpMethod = "POST"
diff --git a/Sources/ExtendedLocalFileProvider.swift b/Sources/ExtendedLocalFileProvider.swift
index 810a434..d00a93f 100644
--- a/Sources/ExtendedLocalFileProvider.swift
+++ b/Sources/ExtendedLocalFileProvider.swift
@@ -10,11 +10,6 @@ import Foundation
 import ImageIO
 import CoreGraphics
 import AVFoundation
-#if os(iOS) || os(tvOS)
-import UIKit
-#elseif os(macOS)
-import Cocoa
-#endif
 
 extension LocalFileProvider: ExtendedFileProvider {
     public func thumbnailOfFileSupported(path: String) -> Bool {
diff --git a/Sources/FPSStreamTask.swift b/Sources/FPSStreamTask.swift
index c8cfb61..9fcc2c8 100644
--- a/Sources/FPSStreamTask.swift
+++ b/Sources/FPSStreamTask.swift
@@ -13,7 +13,6 @@ private var lasttaskIdAssociated = 1_000_000_000
 
 /// This class is a replica of NSURLSessionStreamTask with same api for iOS 7/8
 /// while it will fallback to NSURLSessionStreamTask in iOS 9.
-@objc
 internal class FPSStreamTask: URLSessionTask, StreamDelegate {
     fileprivate var inputStream: InputStream?
     fileprivate var outputStream: OutputStream?
diff --git a/Sources/FileObject.swift b/Sources/FileObject.swift
index a715359..68d0901 100644
--- a/Sources/FileObject.swift
+++ b/Sources/FileObject.swift
@@ -156,6 +156,25 @@ open class FileObject: Equatable {
         }
         return rhs.path == lhs.path && rhs.size == lhs.size && rhs.modifiedDate == lhs.modifiedDate
     }
+    
+    internal  func mapPredicate() -> [String: Any] {
+        let mapDict: [URLResourceKey: String] = [.fileURL: "url", .nameKey: "name", .pathKey: "path", .fileSizeKey: "filesize", .creationDateKey: "creationDate",
+                                                 .contentModificationDateKey: "modifiedDate", .isHiddenKey: "isHidden", .isWritableKey: "isWritable", .serverDate: "serverDate", .entryTag: "entryTag", .mimeType: "mimeType"]
+        let typeDict: [URLFileResourceType: String] = [.directory: "directory", .regular: "regular", .symbolicLink: "symbolicLink", .unknown: "unknown"]
+        var result = [String: Any]()
+        for (key, value) in allValues {
+            if let convertkey = mapDict[key] {
+                result[convertkey] = value
+            }
+        }
+        result["eTag"] = result["entryTag"]
+        result["isReadOnly"] = self.isReadOnly
+        result["isDirectory"] = self.isDirectory
+        result["isRegularFile"] = self.isRegularFile
+        result["isSymLink"] = self.isSymLink
+        result["type"] = typeDict[self.type ?? .unknown] ?? "unknown"
+        return result
+    }
 }
 
 internal func resolve(dateString: String) -> Date? {
diff --git a/Sources/FileProvider.swift b/Sources/FileProvider.swift
index 3bfd635..0bcec41 100644
--- a/Sources/FileProvider.swift
+++ b/Sources/FileProvider.swift
@@ -68,7 +68,7 @@ public protocol FileProviderBasic: class {
      If the directory contains no entries or an error is occured, this method will return the empty array.
      
      - Parameter path: path to target directory. If empty, `currentPath` value will be used.
-     - Parameter completionHandler: a block with result of directory entries or error.
+     - Parameter completionHandler: a closure with result of directory entries or error.
         `contents`: An array of `FileObject` identifying the the directory entries.
         `error`: Error returned by system.
      */
@@ -80,7 +80,7 @@ public protocol FileProviderBasic: class {
      If the directory contains no entries or an error is occured, this method will return the empty `FileObject`.
      
      - Parameter path: path to target directory. If empty, `currentPath` value will be used.
-     - Parameter completionHandler: a block with result of directory entries or error.
+     - Parameter completionHandler: a closure with result of directory entries or error.
         `attributes`: A `FileObject` containing the attributes of the item.
         `error`: Error returned by system.
      */
@@ -90,6 +90,41 @@ public protocol FileProviderBasic: class {
     /// Returns total and used capacity in provider container asynchronously.
     func storageProperties(completionHandler: @escaping ((_ total: Int64, _ used: Int64) -> Void))
     
+    /**
+     Search files inside directory using query asynchronously.
+     
+     - Note: Query string is limited to file name, to search based on other file properties, use NSPredicate version.
+     
+     - Parameters:
+       - path: location of directory to start search
+       - recursive: Searching subdirectories of path
+       - query: Simple string that file name contains to be search, case-insensitive.
+       - foundItemHandler: Closure which is called when a file is found
+       - completionHandler: Closure which will be called after finishing search. Returns an arry of `FileObject` or error if occured.
+     */
+    func searchFiles(path: String, recursive: Bool, query: String, foundItemHandler: ((FileObject) -> Void)?, completionHandler: @escaping ((_ files: [FileObject], _ error: Error?) -> Void))
+    
+    /**
+     Search files inside directory using query asynchronously.
+     
+     Sample predicates:
+     ```
+     NSPredicate(format: "(name CONTAINS[c] 'hello') && (filesize >= 10000)")
+     NSPredicate(format: "(modifiedDate >= %@)", Date())
+     NSPredicate(format: "(path BEGINSWITH %@)", "folder/child folder")
+     ```
+     
+     - Note: Don't pass Spotlight predicates to this method directly, use `FileProvider.convertSpotlightPredicateTo()` method to get usable predicate.
+     
+     - Parameters:
+       - path: location of directory to start search
+       - recursive: Searching subdirectories of path
+       - query: An `NSPredicate` object with keys like `FileObject` members, except `size` which becomes `filesize`.
+       - foundItemHandler: Closure which is called when a file is found
+       - completionHandler: Closure which will be called after finishing search. Returns an arry of `FileObject` or error if occured.
+     */
+    func searchFiles(path: String, recursive: Bool, query: NSPredicate, foundItemHandler: ((FileObject) -> Void)?, completionHandler: @escaping ((_ files: [FileObject], _ error: Error?) -> Void))
+    
     /**
      Returns an independent url to access the file. Some providers like `Dropbox` due to their nature.
      don't return an absolute url to be used to access file directly.
@@ -103,6 +138,39 @@ public protocol FileProviderBasic: class {
 }
 
 extension FileProviderBasic {
+    public func searchFiles(path: String, recursive: Bool, query: String, foundItemHandler: ((FileObject) -> Void)?, completionHandler: @escaping ((_ files: [FileObject], _ error: Error?) -> Void)) {
+        let predicate = NSPredicate(format: "name CONTAINS[c] %@", query)
+        self.searchFiles(path: path, recursive: recursive, query: predicate, foundItemHandler: foundItemHandler, completionHandler: completionHandler)
+    }
+    
+    /// Converts Spotlight search predicate to `FileProvider.searchFiles()` method usable predicate.
+    public func convertSpotlightPredicateTo(_ query: NSPredicate) -> NSPredicate {
+        let mapDict: [String: URLResourceKey] = [NSMetadataItemURLKey: .fileURL, NSMetadataItemFSNameKey: .nameKey, NSMetadataItemPathKey: .pathKey,
+                                                 NSMetadataItemFSSizeKey: .fileSizeKey, NSMetadataItemFSCreationDateKey: .creationDateKey,
+                                                 NSMetadataItemFSContentChangeDateKey: .contentModificationDateKey, "kMDItemFSInvisible": .isHiddenKey, "kMDItemFSIsWriteable": .isWritableKey, "kMDItemKind": .mimeType]
+        
+        if let cQuery = query as? NSCompoundPredicate {
+            let newSub = cQuery.subpredicates.map { convertSpotlightPredicateTo($0 as! NSPredicate) }
+            switch cQuery.compoundPredicateType {
+            case .and: return NSCompoundPredicate(andPredicateWithSubpredicates: newSub)
+            case .not: return NSCompoundPredicate(notPredicateWithSubpredicate: newSub[0])
+            case .or:  return NSCompoundPredicate(orPredicateWithSubpredicates: newSub)
+            }
+        } else if let cQuery = query as? NSComparisonPredicate {
+            var newLeft = cQuery.leftExpression
+            var newRight = cQuery.rightExpression
+            if newLeft.expressionType == .keyPath, let newKey = mapDict[newLeft.keyPath] {
+                newLeft = NSExpression(forKeyPath: newKey.rawValue)
+            }
+            if newRight.expressionType == .keyPath, let newKey = mapDict[newRight.keyPath] {
+                newRight = NSExpression(forKeyPath: newKey.rawValue)
+            }
+            return NSComparisonPredicate(leftExpression: newLeft, rightExpression: newRight, modifier: cQuery.comparisonPredicateModifier, type: cQuery.predicateOperatorType, options: cQuery.options)
+        } else {
+            return query
+        }
+    }
+    
     /// The maximum number of queued operations that can execute at the same time.
     ///
     /// The default value of this property is `OperationQueue.defaultMaxConcurrentOperationCount`.
@@ -114,6 +182,26 @@ extension FileProviderBasic {
             operation_queue.maxConcurrentOperationCount = newValue
         }
     }
+    
+    internal func findNameQuery(_ query: NSPredicate, key: String?) -> Any? {
+        if let cQuery = query as? NSCompoundPredicate {
+            let find = cQuery.subpredicates.flatMap { findNameQuery($0 as! NSPredicate, key: key) }
+            if find.count > 0 {
+                return find[0]
+            }
+            return nil
+        } else if let cQuery = query as? NSComparisonPredicate {
+            if cQuery.leftExpression.expressionType == .keyPath, key == nil || cQuery.leftExpression.keyPath == key! {
+                return cQuery.rightExpression.constantValue
+            }
+            if cQuery.rightExpression.expressionType == .keyPath, key == nil || cQuery.rightExpression.keyPath == key! {
+                return cQuery.leftExpression.constantValue
+            }
+            return nil
+        } else {
+            return nil
+        }
+    }
 }
 
 /// Checking equality of two file provider, regardless of current path queues and delegates.
@@ -133,10 +221,18 @@ public protocol FileProviderBasicRemote: FileProviderBasic {
     /// Underlying URLSession instance used for HTTP/S requests
     var session: URLSession { get }
     
-    /// A `URLCache` to cache downloaded files and contents.
-    ///
-    /// If set to nil, `URLCache.shared` object will be used.
-    /// - Note: It has no effect unless setting `useCache` property to `true`.
+    /**
+     A `URLCache` to cache downloaded files and contents.
+     
+     - Note: It has no effect unless setting `useCache` property to `true`.
+     
+     - Warning: FileProvider doesn't manage/free `URLCache` object in a memory pressure scenario. It's upon you to clear
+     cache memory when receiving `didReceiveMemoryWarning` or via observing `.UIApplicationDidReceiveMemoryWarning` notification.
+     To clear memory usage use this code:
+     ```
+     provider.cache?.removeAllCachedResponses()
+     ```
+     */
     var cache: URLCache? { get }
     
     /// Determine to use `cache` property to cache downloaded file objects. Doesn't have effect on query type methods.
@@ -224,7 +320,6 @@ public protocol FileProviderOperations: FileProviderBasic {
      - Returns: An `OperationHandle` to get progress or cancel progress. Doesn't work on `LocalFileProvider`.
      */
     @discardableResult
-    
     func create(file: String, at: String, contents data: Data?, completionHandler: SimpleCompletionHandler) -> OperationHandle?
     
     /**
@@ -363,7 +458,7 @@ public protocol FileProviderReadWrite: FileProviderBasic {
      
      - Parameters:
        - path: Path of file.
-       - completionHandler: a block with result of file contents or error.
+       - completionHandler: a closure with result of file contents or error.
          `contents`: contents of file in a `Data` object.
          `error`: Error returned by system.
      - Returns: An `OperationHandle` to get progress or cancel progress. Doesn't work on `LocalFileProvider`.
@@ -379,7 +474,7 @@ public protocol FileProviderReadWrite: FileProviderBasic {
        - path: Path of file.
        - offset: First byte index which should be read. **Starts from 0.**
        - length: Bytes count of data. Pass `-1` to read until the end of file.
-       - completionHandler: a block with result of file contents or error.
+       - completionHandler: a closure with result of file contents or error.
          `contents`: contents of file in a `Data` object.
          `error`: Error returned by system.
      - Returns: An `OperationHandle` to get progress or cancel progress. Doesn't work on `LocalFileProvider`.
@@ -442,20 +537,6 @@ public protocol FileProviderReadWrite: FileProviderBasic {
      */
     @discardableResult
     func writeContents(path: String, contents: Data, atomically: Bool, overwrite: Bool, completionHandler: SimpleCompletionHandler) -> OperationHandle?
-    
-    /**
-     Search files inside directory using query asynchronously.
-     
-     - Note: For now only it's limited to file names. `query` parameter may take `NSPredicate` format in near future.
-     
-     - Parameters:
-       - path: location of directory to start search
-       - recursive: Searching subdirectories of path
-       - query: Simple string of file name to be search (for now).
-       - foundItemHandler: Block which is called when a file is found
-       - completionHandler: Block which will be called after finishing search. Returns an arry of `FileObject` or error if occured.
-     */
-    func searchFiles(path: String, recursive: Bool, query: String, foundItemHandler: ((FileObject) -> Void)?, completionHandler: @escaping ((_ files: [FileObject], _ error: Error?) -> Void))
 }
 
 extension FileProviderReadWrite {
@@ -496,7 +577,7 @@ public protocol FileProviderMonitor: FileProviderBasic {
     
      - Parameters:
        - path: path of directory.
-       - eventHandler: Block executed after change, on a secondary thread.
+       - eventHandler: Closure executed after change, on a secondary thread.
      */
     func registerNotifcation(path: String, eventHandler: @escaping (() -> Void))
     
@@ -614,7 +695,7 @@ extension FileProviderBasic {
     /// - Returns: A `String` contains relative path of url against base url.
     public func relativePathOf(url: URL) -> String {
         // check if url derieved from current base url
-        if url.relativeString.isEmpty, url.baseURL == self.baseURL {
+        if !url.relativePath.isEmpty, url.baseURL == self.baseURL {
             return url.relativePath.removingPercentEncoding!
         }
         
@@ -710,7 +791,7 @@ public protocol ExtendedFileProvider: FileProviderBasic {
      
      - Parameters:
        - path: path of file.
-       - completionHandler: a block with result of preview image or error.
+       - completionHandler: a closure with result of preview image or error.
          `image`: `NSImage`/`UIImage` object contains preview.
          `error`: Error returned by system.
     */
@@ -726,7 +807,7 @@ public protocol ExtendedFileProvider: FileProviderBasic {
      - Parameters:
        - path: path of file.
        - dimension: width and height of result preview image.
-       - completionHandler: a block with result of preview image or error.
+       - completionHandler: a closure with result of preview image or error.
          `image`: `NSImage`/`UIImage` object contains preview.
      `error`: Error returned by system.
      */
@@ -741,7 +822,7 @@ public protocol ExtendedFileProvider: FileProviderBasic {
      
      - Parameters:
        - path: path of file.
-       - completionHandler: a block with result of preview image or error.
+       - completionHandler: a closure with result of preview image or error.
          `propertiesDictionary`: A `Dictionary` of proprty keys and values.
          `keys`: An `Array` contains ordering of keys.
          `error`: Error returned by system.
diff --git a/Sources/LocalFileProvider.swift b/Sources/LocalFileProvider.swift
index 39c0d30..845bb15 100644
--- a/Sources/LocalFileProvider.swift
+++ b/Sources/LocalFileProvider.swift
@@ -23,8 +23,10 @@ open class LocalFileProvider: FileProvider, FileProviderMonitor, FileProvideUndo
     open var operation_queue: OperationQueue
     open weak var delegate: FileProviderDelegate?
     open internal(set) var credential: URLCredential?
-        
+    
+    /// Underlying `FileManager` object for listing and metadata fetching.
     open private(set) var fileManager = FileManager()
+    /// Underlying `FileManager` object for operationa like copying, moving, etc.
     open private(set) var opFileManager = FileManager()
     fileprivate var fileProviderManagerDelegate: LocalFileProviderManagerDelegate? = nil
     
@@ -61,7 +63,7 @@ open class LocalFileProvider: FileProvider, FileProviderMonitor, FileProvideUndo
      default values are `directory: .documentDirectory`.
     
      - Parameters:
-       - sharedContainerId: Same  with `App Group` identifier defined in project settings.
+       - sharedContainerId: Same with `App Group` identifier defined in project settings.
        - directory: The search path directory. The supported values are described in `FileManager.SearchPathDirectory`.
     */
     public convenience init? (sharedContainerId: String, directory: FileManager.SearchPathDirectory = .documentDirectory) {
@@ -85,6 +87,7 @@ open class LocalFileProvider: FileProvider, FileProviderMonitor, FileProvideUndo
         }
         
         self.init(baseURL: finalBaseURL)
+        self.isCoorinating = true
         
         try? fileManager.createDirectory(at: finalBaseURL, withIntermediateDirectories: true)
     }
@@ -132,6 +135,12 @@ open class LocalFileProvider: FileProvider, FileProviderMonitor, FileProvideUndo
         }
     }
     
+    open func attributesOfItem(path: String, completionHandler: @escaping ((_ attributes: FileObject?, _ error: Error?) -> Void)) {
+        dispatch_queue.async {
+            completionHandler(LocalFileObject(fileWithPath: path, relativeTo: self.baseURL), nil)
+        }
+    }
+    
     open func storageProperties(completionHandler: (@escaping (_ total: Int64, _ used: Int64) -> Void)) {
         let values = try? baseURL?.resourceValues(forKeys: [.volumeTotalCapacityKey, .volumeAvailableCapacityKey])
         let totalSize = Int64(values??.volumeTotalCapacity ?? -1)
@@ -139,9 +148,21 @@ open class LocalFileProvider: FileProvider, FileProviderMonitor, FileProvideUndo
         completionHandler(totalSize, totalSize - freeSize)
     }
     
-    open func attributesOfItem(path: String, completionHandler: @escaping ((_ attributes: FileObject?, _ error: Error?) -> Void)) {
+    open func searchFiles(path: String, recursive: Bool, query: NSPredicate, foundItemHandler: ((FileObject) -> Void)?, completionHandler: @escaping ((_ files: [FileObject], _ error: Error?) -> Void)) {
         dispatch_queue.async {
-            completionHandler(LocalFileObject(fileWithPath: path, relativeTo: self.baseURL), nil)
+            let iterator = self.fileManager.enumerator(at: self.url(of: path), includingPropertiesForKeys: nil, options: recursive ? [] : [.skipsSubdirectoryDescendants, .skipsPackageDescendants]) { (url, e) -> Bool in
+                completionHandler([], e)
+                return true
+            }
+            var result = [LocalFileObject]()
+            while let fileURL = iterator?.nextObject() as? URL {
+                let path = self.relativePathOf(url: fileURL)
+                if let fileObject = LocalFileObject(fileWithPath: path, relativeTo: self.baseURL), query.evaluate(with: fileObject.mapPredicate()) {
+                    result.append(fileObject)
+                    foundItemHandler?(fileObject)
+                }
+            }
+            completionHandler(result, nil)
         }
     }
     
@@ -227,26 +248,24 @@ open class LocalFileProvider: FileProvider, FileProviderMonitor, FileProvideUndo
     
     @discardableResult
     fileprivate func doOperation(_ opType: FileOperationType, data: Data? = nil, atomically: Bool = false, forUploading: Bool = false, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
+        
+        func urlofpath(path: String) -> URL {
+            if path.hasPrefix("file://") {
+                let removedSchemePath = path.replacingOccurrences(of: "file://", with: "", options: .anchored)
+                let pDecodedPath = removedSchemePath.removingPercentEncoding ?? removedSchemePath
+                return URL(fileURLWithPath: pDecodedPath)
+            } else {
+                return self.url(of: path)
+            }
+        }
+        
         guard let sourcePath = opType.source else { return nil }
         let destPath = opType.destination
-        let source: URL
-        if sourcePath.hasPrefix("file://") {
-            let removedSchemePath = sourcePath.replacingOccurrences(of: "file://", with: "", options: .anchored)
-            let pDecodedPath = removedSchemePath.removingPercentEncoding ?? removedSchemePath
-            source = URL(fileURLWithPath: pDecodedPath)
-        } else {
-            source = self.url(of: sourcePath)
-        }
+        let source: URL = urlofpath(path: sourcePath)
         
         let dest: URL?
         if let destPath = destPath {
-            if destPath.hasPrefix("file://") {
-                let removedSchemePath = destPath.replacingOccurrences(of: "file://", with: "", options: .anchored)
-                let pDecodedPath = removedSchemePath.removingPercentEncoding ?? removedSchemePath
-                dest = URL(fileURLWithPath: pDecodedPath)
-            } else {
-                dest = self.url(of: destPath)
-            }
+            dest = urlofpath(path: destPath)
         } else {
             dest = nil
         }
@@ -307,8 +326,8 @@ open class LocalFileProvider: FileProvider, FileProviderMonitor, FileProvideUndo
         }
         
         if isCoorinating {
-            var intents = [NSFileAccessIntent]()
             successfulSecurityScopedResourceAccess = source.startAccessingSecurityScopedResource()
+            var intents = [NSFileAccessIntent]()
             switch opType {
             case .create, .modify:
                 intents.append(NSFileAccessIntent.writingIntent(with: source, options: .forReplacing))
@@ -452,26 +471,6 @@ open class LocalFileProvider: FileProvider, FileProviderMonitor, FileProvideUndo
         return self.doOperation(opType, data: data, atomically: atomically, completionHandler: completionHandler)
     }
     
-    open func searchFiles(path: String, recursive: Bool, query: String, foundItemHandler: ((FileObject) -> Void)?, completionHandler: @escaping ((_ files: [FileObject], _ error: Error?) -> Void)) {
-        dispatch_queue.async { 
-            let iterator = self.fileManager.enumerator(at: self.url(of: path), includingPropertiesForKeys: nil, options: recursive ? [] : [.skipsSubdirectoryDescendants, .skipsPackageDescendants]) { (url, e) -> Bool in
-                completionHandler([], e)
-                return true
-            }
-            var result = [LocalFileObject]()
-            while let fileURL = iterator?.nextObject() as? URL {
-                if fileURL.lastPathComponent.lowercased().contains(query.lowercased()) {
-                    let path = self.relativePathOf(url: fileURL)
-                    if let fileObject = LocalFileObject(fileWithPath: path, relativeTo: self.baseURL) {
-                        result.append(fileObject)
-                        foundItemHandler?(fileObject)
-                    }
-                }
-            }
-            completionHandler(result, nil)
-        }
-    }
-    
     fileprivate var monitors = [LocalFolderMonitor]()
     
     open func registerNotifcation(path: String, eventHandler: @escaping (() -> Void)) {
@@ -500,7 +499,7 @@ open class LocalFileProvider: FileProvider, FileProviderMonitor, FileProvideUndo
     }
     
     open func isRegisteredForNotification(path: String) -> Bool {
-        return monitors.map( { self.relativePathOf(url: $0.url) } ).contains(path)
+        return monitors.map( { self.relativePathOf(url: $0.url) } ).contains(path.trimmingCharacters(in: CharacterSet(charactersIn: "/")))
     }
     
     open func copy(with zone: NSZone? = nil) -> Any {
diff --git a/Sources/OneDriveFileProvide.swift b/Sources/OneDriveFileProvide.swift
index 2e65c7e..e9522b8 100644
--- a/Sources/OneDriveFileProvide.swift
+++ b/Sources/OneDriveFileProvide.swift
@@ -71,7 +71,7 @@ open class OneDriveFileProvider: FileProviderBasicRemote {
        - serverURL: server url, Set it if you are trying to connect OneDrive Business server, otherwise leave it
          `nil` to connect to OneDrive Personal uses.
        - drive: drive name for user on server, default value is `root`.
-       - cache: A URLCache to cache downloaded files and contents. If set to nil, URLCache.shared object will be used.
+       - cache: A URLCache to cache downloaded files and contents.
      */
     public init(credential: URLCredential?, serverURL: URL? = nil, drive: String = "root", cache: URLCache? = nil) {
         let baseURL = serverURL ?? URL(string: "https://api.onedrive.com/")!
@@ -139,6 +139,21 @@ open class OneDriveFileProvider: FileProviderBasicRemote {
         task.resume()
     }
     
+    open func searchFiles(path: String, recursive: Bool, query: NSPredicate, foundItemHandler: ((FileObject) -> Void)?, completionHandler: @escaping ((_ files: [FileObject], _ error: Error?) -> Void)) {
+        var foundFiles = [OneDriveFileObject]()
+        var queryStr: String?
+        queryStr = self.findNameQuery(query, key: "name") as? String ?? self.findNameQuery(query, key: nil) as? String
+        guard let finalQueryStr = queryStr else { return }
+        search(path, query: finalQueryStr, foundItem: { (file) in
+            if query.evaluate(with: file.mapPredicate()) {
+                foundFiles.append(file)
+                foundItemHandler?(file)
+            }
+        }, completionHandler: { (error) in
+            completionHandler(foundFiles, error)
+        })
+    }
+    
     open func isReachable(completionHandler: @escaping (Bool) -> Void) {
         let url = URL(string: "/drive/root", relativeTo: baseURL)!
         var request = URLRequest(url: url)
@@ -157,25 +172,25 @@ open class OneDriveFileProvider: FileProviderBasicRemote {
 extension OneDriveFileProvider: FileProviderOperations {
     
     
-    public func create(folder folderName: String, at atPath: String, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
+    open func create(folder folderName: String, at atPath: String, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
         let path = (atPath as NSString).appendingPathComponent(folderName) + "/"
         return doOperation(.create(path: path), completionHandler: completionHandler)
     }
     
-    public func create(file fileName: String, at path: String, contents data: Data?, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
+    open func create(file fileName: String, at path: String, contents data: Data?, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
         let filePath = (path as NSString).appendingPathComponent(fileName)
         return self.writeContents(path: filePath, contents: data ?? Data(), completionHandler: completionHandler)
     }
     
-    public func moveItem(path: String, to toPath: String, overwrite: Bool, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
+    open func moveItem(path: String, to toPath: String, overwrite: Bool, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
         return doOperation(.move(source: path, destination: toPath), completionHandler: completionHandler)
     }
     
-    public func copyItem(path: String, to toPath: String, overwrite: Bool, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
+    open func copyItem(path: String, to toPath: String, overwrite: Bool, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
         return doOperation(.copy(source: path, destination: toPath), completionHandler: completionHandler)
     }
     
-    public func removeItem(path: String, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
+    open func removeItem(path: String, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
         return doOperation(.remove(path: path), completionHandler: completionHandler)
     }
     
@@ -220,7 +235,7 @@ extension OneDriveFileProvider: FileProviderOperations {
         return RemoteOperationHandle(operationType: operation, tasks: [task])
     }
     
-    public func copyItem(localFile: URL, to toPath: String, overwrite: Bool, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
+    open func copyItem(localFile: URL, to toPath: String, overwrite: Bool, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
         let opType = FileOperationType.copy(source: localFile.absoluteString, destination: toPath)
         guard fileOperationDelegate?.fileProvider(self, shouldDoOperation: opType) ?? true == true else {
             return nil
@@ -228,7 +243,7 @@ extension OneDriveFileProvider: FileProviderOperations {
         return upload_simple(toPath, localFile: localFile, overwrite: overwrite, operation: opType, completionHandler: completionHandler)
     }
     
-    public func copyItem(path: String, toLocalURL destURL: URL, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
+    open func copyItem(path: String, toLocalURL destURL: URL, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
         let opType = FileOperationType.copy(source: path, destination: destURL.absoluteString)
         guard fileOperationDelegate?.fileProvider(self, shouldDoOperation: opType) ?? true == true else {
             return nil
@@ -259,7 +274,7 @@ extension OneDriveFileProvider: FileProviderOperations {
 }
 
 extension OneDriveFileProvider: FileProviderReadWrite {
-    public func contents(path: String, offset: Int64, length: Int, completionHandler: @escaping ((_ contents: Data?, _ error: Error?) -> Void)) -> OperationHandle? {
+    open func contents(path: String, offset: Int64, length: Int, completionHandler: @escaping ((_ contents: Data?, _ error: Error?) -> Void)) -> OperationHandle? {
         if length == 0 || offset < 0 {
             dispatch_queue.async {
                 completionHandler(Data(), nil)
@@ -290,7 +305,7 @@ extension OneDriveFileProvider: FileProviderReadWrite {
         return RemoteOperationHandle(operationType: opType, tasks: [task])
     }
     
-    public func writeContents(path: String, contents data: Data, atomically: Bool, overwrite: Bool, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
+    open func writeContents(path: String, contents data: Data, atomically: Bool, overwrite: Bool, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
         let opType = FileOperationType.modify(path: path)
         guard fileOperationDelegate?.fileProvider(self, shouldDoOperation: opType) ?? true == true else {
             return nil
@@ -299,16 +314,6 @@ extension OneDriveFileProvider: FileProviderReadWrite {
         return upload_simple(path, data: data, overwrite: overwrite, operation: opType, completionHandler: completionHandler)
     }
     
-    public func searchFiles(path: String, recursive: Bool, query: String, foundItemHandler: ((FileObject) -> Void)?, completionHandler: @escaping ((_ files: [FileObject], _ error: Error?) -> Void)) {
-        var foundFiles = [OneDriveFileObject]()
-        search(path, query: query, foundItem: { (file) in
-            foundFiles.append(file)
-            foundItemHandler?(file)
-            }, completionHandler: { (error) in
-                completionHandler(foundFiles, error)
-        })
-    }
-    
     fileprivate func registerNotifcation(path: String, eventHandler: (() -> Void)) {
         /* There is two ways to monitor folders changing in OneDrive. Either using webooks
          * which means you have to implement a server to translate it to push notifications
@@ -327,7 +332,7 @@ extension OneDriveFileProvider: FileProviderReadWrite {
      
      - Parameters:
        - to: path of file, including file/directory name.
-       - completionHandler: a block with result of directory entries or error.
+       - completionHandler: a closure with result of directory entries or error.
          `link`: a url returned by OneDrive to share.
          `attribute`: `nil` for OneDrive.
          `expiration`: `nil` for OneDrive, as it doesn't expires.
@@ -360,11 +365,11 @@ extension OneDriveFileProvider: FileProviderReadWrite {
 
 
 extension OneDriveFileProvider: ExtendedFileProvider {
-    public func thumbnailOfFileSupported(path: String) -> Bool {
+    open func thumbnailOfFileSupported(path: String) -> Bool {
         return true
     }
     
-    public func propertiesOfFileSupported(path: String) -> Bool {
+    open func propertiesOfFileSupported(path: String) -> Bool {
         let fileExt = (path as NSString).pathExtension.lowercased()
         switch fileExt {
         case "jpg", "jpeg", "bmp", "gif", "png", "tif", "tiff":
@@ -378,7 +383,7 @@ extension OneDriveFileProvider: ExtendedFileProvider {
         }
     }
     
-    public func thumbnailOfFile(path: String, dimension: CGSize?, completionHandler: @escaping ((_ image: ImageClass?, _ error: Error?) -> Void)) {
+    open func thumbnailOfFile(path: String, dimension: CGSize?, completionHandler: @escaping ((_ image: ImageClass?, _ error: Error?) -> Void)) {
         let url: URL
         if let dimension = dimension {
             url = URL(string: escaped(path: path) + ":/thumbnails/0/=c\(dimension.width)x\(dimension.height)/content", relativeTo: driveURL)!
@@ -403,7 +408,7 @@ extension OneDriveFileProvider: ExtendedFileProvider {
         task.resume()
     }
     
-    public func propertiesOfFile(path: String, completionHandler: @escaping ((_ propertiesDictionary: [String : Any], _ keys: [String], _ error: Error?) -> Void)) {
+    open func propertiesOfFile(path: String, completionHandler: @escaping ((_ propertiesDictionary: [String : Any], _ keys: [String], _ error: Error?) -> Void)) {
         let url = URL(string: escaped(path: path), relativeTo: driveURL)!
         var request = URLRequest(url: url)
         request.httpMethod = "GET"
diff --git a/Sources/RemoteSession.swift b/Sources/RemoteSession.swift
index cb50445..b8a03c3 100644
--- a/Sources/RemoteSession.swift
+++ b/Sources/RemoteSession.swift
@@ -8,7 +8,7 @@
 
 import Foundation
 
-/// Allows to get progress or cancel an in-progress operation, for remote -URLSession based- providers.
+/// Allows to get progress or cancel an in-progress operation, for remote, `URLSession` based providers.
 open class RemoteOperationHandle: OperationHandle {
     
     internal var tasks: [Weak<URLSessionTask>]
@@ -43,7 +43,7 @@ open class RemoteOperationHandle: OperationHandle {
             if let task = $1.value as? URLSessionUploadTask {
                 return $0 + task.countOfBytesExpectedToSend
             } else {
-                return $0 + ($1.value?.countOfBytesExpectedToSend ?? 0)
+                return $0 + ($1.value?.countOfBytesExpectedToReceive ?? 0)
             }
         }
     }
@@ -71,8 +71,6 @@ public protocol FileProviderHTTPError: Error, CustomStringConvertible {
     var path: String { get }
     /// Contents returned by server as error description
     var errorDescription: String? { get }
-    
-    var description: String { get }
 }
 
 extension FileProviderHTTPError {
@@ -309,7 +307,7 @@ public enum FileProviderHTTPErrorCode: Int, CustomStringConvertible {
         case 300...399: return "Redirection"
         case 400...499: return "Client Error"
         case 500...599: return "Server Error"
-        default: return "Server Error"
+        default: return "Unknown Error"
         }
     }
 }
diff --git a/Sources/SMBFileProvider.swift b/Sources/SMBFileProvider.swift
index 7444fa5..f67cc54 100644
--- a/Sources/SMBFileProvider.swift
+++ b/Sources/SMBFileProvider.swift
@@ -100,7 +100,7 @@ class SMBFileProvider: FileProvider, FileProviderMonitor {
         return nil
     }
     
-    open func searchFiles(path: String, recursive: Bool, query: String, foundItemHandler:((FileObjectClass) -> Void)?, completionHandler: @escaping ((_ files: [FileObjectClass], _ error: Error?) -> Void)) {
+    open func searchFiles(path: String, recursive: Bool, query: NSPredicate, foundItemHandler:((FileObjectClass) -> Void)?, completionHandler: @escaping ((_ files: [FileObjectClass], _ error: Error?) -> Void)) {
         NotImplemented()
     }
     
diff --git a/Sources/WebDAVFileProvider.swift b/Sources/WebDAVFileProvider.swift
index 628585d..8c377ae 100644
--- a/Sources/WebDAVFileProvider.swift
+++ b/Sources/WebDAVFileProvider.swift
@@ -13,7 +13,7 @@ import Foundation
  set `useCache` and `cache` properties to use Foundation `NSURLCache` system.
  
  WebDAV system supported by many cloud services including [Box.net](https://www.box.com/home) 
- and [Yandex disk](https://disk.yandex.com).
+ and [Yandex disk](https://disk.yandex.com) and [ownCloud](https://owncloud.org).
  
  - Important: Because this class uses `URLSession`, it's necessary to disable App Transport Security
      in case of using this class with unencrypted HTTP connection.
@@ -59,7 +59,7 @@ open class WebDAVFileProvider: FileProviderBasicRemote {
      - Parameters:
        - baseURL: Location of WebDAV server.
        - credential: An `URLCredential` object with `user` and `password`.
-       - cache: A URLCache to cache downloaded files and contents. If set to nil, URLCache.shared object will be used.
+       - cache: A URLCache to cache downloaded files and contents.
     */
     public init? (baseURL: URL, credential: URLCredential?, cache: URLCache? = nil) {
         if  !["http", "https"].contains(baseURL.uw_scheme.lowercased()) {
@@ -164,6 +164,38 @@ open class WebDAVFileProvider: FileProviderBasicRemote {
         })
     }
     
+    open func searchFiles(path: String, recursive: Bool, query: NSPredicate, foundItemHandler: ((FileObject) -> Void)?, completionHandler: @escaping ((_ files: [FileObject], _ error: Error?) -> Void)) {
+        let url = self.url(of: path)
+        var request = URLRequest(url: url)
+        request.httpMethod = "PROPFIND"
+        //request.setValue("1", forHTTPHeaderField: "Depth")
+        request.setValue("text/xml; charset=\"utf-8\"", forHTTPHeaderField: "Content-Type")
+        request.httpBody = "<?xml version=\"1.0\" encoding=\"utf-8\" ?>\n<D:propfind xmlns:D=\"DAV:\">\n<D:allprop/></D:propfind>".data(using: .utf8)
+        runDataTask(with: request, completionHandler: { (data, response, error) in
+            // FIXME: paginating results
+            var responseError: FileProviderWebDavError?
+            if let code = (response as? HTTPURLResponse)?.statusCode , code >= 300, let rCode = FileProviderHTTPErrorCode(rawValue: code) {
+                responseError = FileProviderWebDavError(code: rCode, path: path, errorDescription: String(data: data ?? Data(), encoding: .utf8), url: url)
+            }
+            if let data = data {
+                let xresponse = DavResponse.parse(xmlResponse: data, baseURL: self.baseURL)
+                var fileObjects = [WebDavFileObject]()
+                for attr in xresponse {
+                    let fileObject = WebDavFileObject(attr)
+                    if !query.evaluate(with: fileObject.mapPredicate()) {
+                        continue
+                    }
+                    
+                    fileObjects.append(fileObject)
+                    foundItemHandler?(fileObject)
+                }
+                completionHandler(fileObjects, responseError ?? error)
+                return
+            }
+            completionHandler([], responseError ?? error)
+        })
+    }
+    
     open func isReachable(completionHandler: @escaping (Bool) -> Void) {
         var request = URLRequest(url: baseURL!)
         request.httpMethod = "PROPFIND"
@@ -182,7 +214,7 @@ open class WebDAVFileProvider: FileProviderBasicRemote {
 
 extension WebDAVFileProvider: FileProviderOperations {
     @discardableResult
-    public func create(folder folderName: String, at atPath: String, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
+    open func create(folder folderName: String, at atPath: String, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
         let opType = FileOperationType.create(path: (atPath as NSString).appendingPathComponent(folderName) + "/")
         guard fileOperationDelegate?.fileProvider(self, shouldDoOperation: opType) ?? true == true else {
             return nil
@@ -204,7 +236,7 @@ extension WebDAVFileProvider: FileProviderOperations {
     }
     
     @discardableResult
-    public func create(file fileName: String, at path: String, contents data: Data?, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
+    open func create(file fileName: String, at path: String, contents data: Data?, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
         let opType = FileOperationType.create(path: (path as NSString).appendingPathComponent(fileName))
         guard fileOperationDelegate?.fileProvider(self, shouldDoOperation: opType) ?? true == true else {
             return nil
@@ -226,7 +258,7 @@ extension WebDAVFileProvider: FileProviderOperations {
     }
     
     @discardableResult
-    public func moveItem(path: String, to toPath: String, overwrite: Bool = false, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
+    open func moveItem(path: String, to toPath: String, overwrite: Bool = false, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
         let opType = FileOperationType.move(source: path, destination: toPath)
         guard fileOperationDelegate?.fileProvider(self, shouldDoOperation: opType) ?? true == true else {
             return nil
@@ -235,7 +267,7 @@ extension WebDAVFileProvider: FileProviderOperations {
     }
     
     @discardableResult
-    public func copyItem(path: String, to toPath: String, overwrite: Bool = false, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
+    open func copyItem(path: String, to toPath: String, overwrite: Bool = false, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
         let opType = FileOperationType.copy(source: path, destination: toPath)
         guard fileOperationDelegate?.fileProvider(self, shouldDoOperation: opType) ?? true == true else {
             return nil
@@ -244,7 +276,7 @@ extension WebDAVFileProvider: FileProviderOperations {
     }
     
     @discardableResult
-    public func removeItem(path: String, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
+    open func removeItem(path: String, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
         let opType = FileOperationType.remove(path: path)
         guard fileOperationDelegate?.fileProvider(self, shouldDoOperation: opType) ?? true == true else {
             return nil
@@ -299,7 +331,7 @@ extension WebDAVFileProvider: FileProviderOperations {
     }
     
     @discardableResult
-    public func copyItem(localFile: URL, to toPath: String, overwrite: Bool, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
+    open func copyItem(localFile: URL, to toPath: String, overwrite: Bool, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
         let opType = FileOperationType.copy(source: localFile.absoluteString, destination: toPath)
         guard fileOperationDelegate?.fileProvider(self, shouldDoOperation: opType) ?? true == true else {
             return nil
@@ -324,7 +356,7 @@ extension WebDAVFileProvider: FileProviderOperations {
     }
     
     @discardableResult
-    public func copyItem(path: String, toLocalURL: URL, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
+    open func copyItem(path: String, toLocalURL: URL, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
         let opType = FileOperationType.copy(source: path, destination: toLocalURL.absoluteString)
         guard fileOperationDelegate?.fileProvider(self, shouldDoOperation: opType) ?? true == true else {
             return nil
@@ -355,7 +387,7 @@ extension WebDAVFileProvider: FileProviderOperations {
 
 extension WebDAVFileProvider: FileProviderReadWrite {
     @discardableResult
-    public func contents(path: String, offset: Int64, length: Int, completionHandler: @escaping ((_ contents: Data?, _ error: Error?) -> Void)) -> OperationHandle? {
+    open func contents(path: String, offset: Int64, length: Int, completionHandler: @escaping ((_ contents: Data?, _ error: Error?) -> Void)) -> OperationHandle? {
         if length == 0 || offset < 0 {
             dispatch_queue.async {
                 completionHandler(Data(), nil)
@@ -384,7 +416,7 @@ extension WebDAVFileProvider: FileProviderReadWrite {
     }
     
     @discardableResult
-    public func writeContents(path: String, contents data: Data, atomically: Bool, overwrite: Bool, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
+    open func writeContents(path: String, contents data: Data, atomically: Bool, overwrite: Bool, completionHandler: SimpleCompletionHandler) -> OperationHandle? {
         let opType = FileOperationType.modify(path: path)
         guard fileOperationDelegate?.fileProvider(self, shouldDoOperation: opType) ?? true == true else {
             return nil
@@ -417,38 +449,6 @@ extension WebDAVFileProvider: FileProviderReadWrite {
         return RemoteOperationHandle(operationType: opType, tasks: [task])
     }
     
-    public func searchFiles(path: String, recursive: Bool, query: String, foundItemHandler: ((FileObject) -> Void)?, completionHandler: @escaping ((_ files: [FileObject], _ error: Error?) -> Void)) {
-        let url = self.url(of: path)
-        var request = URLRequest(url: url)
-        request.httpMethod = "PROPFIND"
-        //request.setValue("1", forHTTPHeaderField: "Depth")
-        request.setValue("text/xml; charset=\"utf-8\"", forHTTPHeaderField: "Content-Type")
-        request.httpBody = "<?xml version=\"1.0\" encoding=\"utf-8\" ?>\n<D:propfind xmlns:D=\"DAV:\">\n<D:allprop/></D:propfind>".data(using: .utf8)
-        runDataTask(with: request, completionHandler: { (data, response, error) in
-            // FIXME: paginating results
-            var responseError: FileProviderWebDavError?
-            if let code = (response as? HTTPURLResponse)?.statusCode , code >= 300, let rCode = FileProviderHTTPErrorCode(rawValue: code) {
-                responseError = FileProviderWebDavError(code: rCode, path: path, errorDescription: String(data: data ?? Data(), encoding: .utf8), url: url)
-            }
-            if let data = data {
-                let xresponse = DavResponse.parse(xmlResponse: data, baseURL: self.baseURL)
-                var fileObjects = [WebDavFileObject]()
-                for attr in xresponse {
-                    let path = attr.href.path
-                    if !((path as NSString).lastPathComponent.contains(query)) {
-                        continue
-                    }
-                    let fileObject = WebDavFileObject(attr)
-                    fileObjects.append(fileObject)
-                    foundItemHandler?(fileObject)
-                }
-                completionHandler(fileObjects, responseError ?? error)
-                return
-            }
-            completionHandler([], responseError ?? error)
-        })
-    }
-    
     /*
     fileprivate func registerNotifcation(path: String, eventHandler: (() -> Void)) {
         /* There is no unified api for monitoring WebDAV server content change/update