Refactored paginated listing in Dropbox and OneDrive

- Removed currentPath

Sources/CloudFileProvider.swift

@@ -94,20 +94,17 @@ open class CloudFileProvider: LocalFileProvider, FileProviderSharing {
             return nil
         }
         self.init(containerId: containerId, scope: scope)
-        self.currentPath   = aDecoder.decodeObject(forKey: "currentPath") as? String ?? ""
         self.isCoorinating = aDecoder.decodeBool(forKey: "isCoorinating")
     }
     
     open override func encode(with aCoder: NSCoder) {
         aCoder.encode(self.containerId, forKey: "containerId")
         aCoder.encode(self.scope.rawValue, forKey: "scope")
-        aCoder.encode(self.currentPath, forKey: "currentPath")
         aCoder.encode(self.isCoorinating, forKey: "isCoorinating")
     }
     
     open override func copy(with zone: NSZone? = nil) -> Any {
         let copy = CloudFileProvider(containerId: self.containerId, scope: self.scope)
-        copy?.currentPath = self.currentPath
         copy?.delegate = self.delegate
         copy?.fileOperationDelegate = self.fileOperationDelegate
         return copy as Any

Sources/DropboxFileProvider.swift

@@ -43,14 +43,12 @@ open class DropboxFileProvider: HTTPFileProvider, FileProviderSharing {
     
     public required convenience init?(coder aDecoder: NSCoder) {
         self.init(credential: aDecoder.decodeObject(forKey: "credential") as? URLCredential)
-        self.currentPath     = aDecoder.decodeObject(forKey: "currentPath") as? String ?? ""
         self.useCache        = aDecoder.decodeBool(forKey: "useCache")
         self.validatingCache = aDecoder.decodeBool(forKey: "validatingCache")
     }
     
     override open func copy(with zone: NSZone? = nil) -> Any {
         let copy = DropboxFileProvider(credential: self.credential, cache: self.cache)
-        copy.currentPath = self.currentPath
         copy.delegate = self.delegate
         copy.fileOperationDelegate = self.fileOperationDelegate
         copy.useCache = self.useCache
@@ -60,10 +58,28 @@ open class DropboxFileProvider: HTTPFileProvider, FileProviderSharing {
     
     open override func contentsOfDirectory(path: String, completionHandler: @escaping (_ contents: [FileObject], _ error: Error?) -> Void) {
         // We don't want this progress became in another progress' hierarchy
-        let progress = Progress(parent: nil, userInfo: nil)
-        list(path, progress: progress) { (contents, cursor, error) in
-            completionHandler(contents, error)
-        }
+        _ = paginated(path, requestHandler: self.listRequest(path: path),
+        pageHandler: { [weak self] (data, progress) -> (files: [FileObject], error: Error?, newToken: String?) in
+            guard let json = data?.deserializeJSON(), let entries = json["entries"] as? [AnyObject] else {
+                let err = self?.urlError(path, code: .badServerResponse)
+                return ([], err, nil)
+            }
+            
+            var files = [FileObject]()
+            for entry in entries {
+                if let entry = entry as? [String: AnyObject], let file = DropboxFileObject(json: entry) {
+                    files.append(file)
+                    progress.completedUnitCount += 1
+                }
+            }
+            let ncursor: String?
+            if let hasmore = (json["has_more"] as? NSNumber)?.boolValue, hasmore {
+                ncursor = json["cursor"] as? String
+            } else {
+                ncursor = nil
+            }
+            return (files, nil, ncursor)
+        }, completionHandler: completionHandler)
     }
     
     open override func attributesOfItem(path: String, completionHandler: @escaping (_ attributes: FileObject?, _ error: Error?) -> Void) {
@@ -109,32 +125,33 @@ open class DropboxFileProvider: HTTPFileProvider, FileProviderSharing {
     }
     
     open override func searchFiles(path: String, recursive: Bool, query: NSPredicate, foundItemHandler: ((FileObject) -> Void)?, completionHandler: @escaping (_ files: [FileObject], _ error: Error?) -> Void) -> Progress? {
-        let progress = Progress(totalUnitCount: -1)
-        var foundFiles = [DropboxFileObject]()
-        if let queryStr = query.findValue(forKey: "name", operator: .beginsWith) as? String {
-            // Dropbox only support searching for file names begin with query in non-enterprise accounts.
-            // We will use it if there is a `name BEGINSWITH[c] "query"` in predicate, then filter to form final result.
-            search(path, query: queryStr, progress: progress, foundItem: { (file) in
-                if query.evaluate(with: file.mapPredicate()) {
-                    foundFiles.append(file)
+        let queryStr = query.findValue(forKey: "name", operator: .beginsWith) as? String
+        let requestHandler = self.listRequest(path: path, queryStr: queryStr, recursive: true)
+        return paginated(path, requestHandler: requestHandler,
+            pageHandler: { [weak self] (data, progress) -> (files: [FileObject], error: Error?, newToken: String?) in
+            guard let json = data?.deserializeJSON(), let entries = (json["entries"] ?? json["matches"]) as? [AnyObject] else {
+                let err = self?.urlError(path, code: .badServerResponse)
+                return ([], err, nil)
+            }
+            
+            var files = [FileObject]()
+            for entry in entries {
+                if let entry = entry as? [String: AnyObject], let file = DropboxFileObject(json: entry), query.evaluate(with: file.mapPredicate()) {
+                    files.append(file)
+                    progress.completedUnitCount += 1
                     foundItemHandler?(file)
                 }
-            }, completionHandler: { (error) in
-                completionHandler(foundFiles, error)
-            })
-        } else {
-            // Dropbox doesn't support searching attributes natively. The workaround is to fallback to listing all files
-            // and filter it locally. It may have a network burden in case there is many files in Dropbox, so please use it concisely.
-            list(path, recursive: true, progress: progress, progressHandler: { (files, _, error) in
-                for file in files where query.evaluate(with: file.mapPredicate()) {
-                    foundItemHandler?(file)
-                }
-            }, completionHandler: { (files, _, error) in
-                let predicatedFiles = files.filter { query.evaluate(with: $0.mapPredicate()) }
-                completionHandler(predicatedFiles, error)
-            })
-        }
-        return progress
+            }
+            let ncursor: String?
+            if let hasmore = (json["has_more"] as? NSNumber)?.boolValue, hasmore {
+                ncursor = json["cursor"] as? String
+            } else if let hasmore = (json["more"] as? NSNumber)?.boolValue, hasmore {
+                ncursor = (json["start"] as? Int).flatMap(String.init)
+            } else {
+                ncursor = nil
+            }
+            return (files, nil, ncursor)
+        }, completionHandler: completionHandler)
     }
     
     override func request(for operation: FileOperationType, overwrite: Bool = false, attributes: [URLResourceKey : Any] = [:]) -> URLRequest {

Sources/DropboxHelper.swift

@@ -72,7 +72,6 @@ public final class DropboxFileObject: FileObject {
     }
 }
 
-// codebeat:disable[ARITY]
 internal extension DropboxFileProvider {
     internal func correctPath(_ path: String?) -> String? {
         guard let path = path else { return nil }
@@ -86,105 +85,44 @@ internal extension DropboxFileProvider {
         return p
     }
     
-    func list(_ path: String, cursor: String? = nil, prevContents: [DropboxFileObject] = [], recursive: Bool = false, session: URLSession? = nil, progress: Progress, progressHandler: ((_ contents: [FileObject], _ nextCursor: String?, _ error: Error?) -> Void)? = nil, completionHandler: @escaping ((_ contents: [FileObject], _ cursor: String?, _ error: Error?) -> Void)) {
-        if progress.isCancelled { return }
-        
-        var requestDictionary = [String: AnyObject]()
-        let url: URL
-        if let cursor = cursor {
-            url = URL(string: "files/list_folder/continue", relativeTo: apiURL)!
-            requestDictionary["cursor"] = cursor as NSString?
+    internal func listRequest(path: String, queryStr: String? = nil, recursive: Bool = false) -> ((_ token: String?) -> URLRequest?) {
+        if let queryStr = queryStr {
+            return { [weak self] (token) -> URLRequest? in
+                guard let `self` = self else { return nil }
+                let url = URL(string: "files/search", relativeTo: self.apiURL)!
+                var request = URLRequest(url: url)
+                request.httpMethod = "POST"
+                request.set(httpAuthentication: self.credential, with: .oAuth2)
+                request.set(httpContentType: .json)
+                var requestDictionary: [String: AnyObject] = ["path": self.correctPath(path) as NSString!]
+                requestDictionary["query"] = queryStr as NSString
+                requestDictionary["start"] = NSNumber(value: (token.flatMap(Int.init) ?? 0))
+                request.httpBody = Data(jsonDictionary: requestDictionary)
+                return request
+            }
         } else {
-            url = URL(string: "files/list_folder", relativeTo: apiURL)!
-            requestDictionary["path"] = correctPath(path) as NSString?
-            requestDictionary["recursive"] = recursive as NSNumber?
-        }
-        var request = URLRequest(url: url)
-        request.httpMethod = "POST"
-        request.set(httpAuthentication: credential, with: .oAuth2)
-        request.set(httpContentType: .json)
-        request.httpBody = Data(jsonDictionary: requestDictionary)
-        let task = (session ?? self.session).dataTask(with: request, completionHandler: { (data, response, error) in
-            var responseError: FileProviderHTTPError?
-            var files = [DropboxFileObject]()
-            if let code = (response as? HTTPURLResponse)?.statusCode , code >= 300, let rCode = FileProviderHTTPErrorCode(rawValue: code) {
-                responseError = self.serverError(with: rCode, path: path, data: data)
-            }
-            if let json = data?.deserializeJSON() {
-                if let entries = json["entries"] as? [AnyObject] , entries.count > 0 {
-                    files.reserveCapacity(entries.count)
-                    for entry in entries {
-                        if let entry = entry as? [String: AnyObject], let file = DropboxFileObject(json: entry) {
-                            files.append(file)
-                            progress.totalUnitCount = Int64(files.count)
-                        }
-                    }
-                    let ncursor = json["cursor"] as? String
-                    let hasmore = (json["has_more"] as? NSNumber)?.boolValue ?? false
-                    if hasmore && !progress.isCancelled {
-                        progressHandler?(files, ncursor, responseError ?? error)
-                        self.list(path, cursor: ncursor, prevContents: prevContents + files, progress: progress, completionHandler: completionHandler)
-                        return
-                    }
+            return { [weak self] (token) -> URLRequest? in
+                guard let `self` = self else { return nil }
+                var requestDictionary = [String: AnyObject]()
+                let url: URL
+                if let token = token {
+                    url = URL(string: "files/list_folder/continue", relativeTo: self.apiURL)!
+                    requestDictionary["cursor"] = token as NSString?
+                } else {
+                    url = URL(string: "files/list_folder", relativeTo: self.apiURL)!
+                    requestDictionary["path"] = self.correctPath(path) as NSString?
+                    requestDictionary["recursive"] = NSNumber(value: recursive)
                 }
+                var request = URLRequest(url: url)
+                request.httpMethod = "POST"
+                request.set(httpAuthentication: self.credential, with: .oAuth2)
+                request.set(httpContentType: .json)
+                request.httpBody = Data(jsonDictionary: requestDictionary)
+                return request
             }
-            progressHandler?(files, nil, responseError ?? error)
-            completionHandler(prevContents + files, nil, responseError ?? error)
-        })
-        progress.cancellationHandler = { [weak task] in
-            task?.cancel()
         }
-        progress.setUserInfoObject(Date(), forKey: .startingTimeKey)
-        task.taskDescription = FileOperationType.fetch(path: path).json
-        task.resume()
-    }
-    
-    func search(_ startPath: String = "", query: String, start: Int = 0, maxResultPerPage: Int = 25, maxResults: Int = -1, progress: Progress, foundItem:@escaping ((_ file: DropboxFileObject) -> Void), completionHandler: @escaping ((_ error: Error?) -> Void)) {
-        if progress.isCancelled { return }
-        
-        let url = URL(string: "files/search", relativeTo: apiURL)!
-        var request = URLRequest(url: url)
-        request.httpMethod = "POST"
-        request.set(httpAuthentication: credential, with: .oAuth2)
-        request.set(httpContentType: .json)
-        var requestDictionary: [String: AnyObject] = ["path": startPath as NSString]
-        requestDictionary["query"] = query as NSString
-        requestDictionary["start"] = start as NSNumber
-        requestDictionary["max_results"] = maxResultPerPage as NSNumber
-        request.httpBody = Data(jsonDictionary: requestDictionary)
-        let task = session.dataTask(with: request, completionHandler: { (data, response, error) in
-            var responseError: FileProviderHTTPError?
-            if let code = (response as? HTTPURLResponse)?.statusCode , code >= 300, let rCode = FileProviderHTTPErrorCode(rawValue: code) {
-                responseError = self.serverError(with: rCode, path: startPath, data: data)
-            }
-            if let json = data?.deserializeJSON() {
-                if let entries = json["matches"] as? [AnyObject] , entries.count > 0 {
-                    for entry in entries {
-                        if let entry = entry as? [String: AnyObject], let file = DropboxFileObject(json: entry) {
-                            foundItem(file)
-                            progress.completedUnitCount += 1
-                        }
-                    }
-                    let rstart = json["start"] as? Int
-                    let hasmore = (json["more"] as? NSNumber)?.boolValue ?? false
-                    if hasmore && !progress.isCancelled, let rstart = rstart {
-                        self.search(startPath, query: query, start: rstart + entries.count, maxResultPerPage: maxResultPerPage, progress: progress, foundItem: foundItem, completionHandler: completionHandler)
-                    } else {
-                        completionHandler(responseError ?? error)
-                    }
-                    return
-                }
-            }
-            completionHandler(responseError ?? error)
-        })
-        progress.cancellationHandler = { [weak task] in
-            task?.cancel()
-        }
-        progress.setUserInfoObject(Date(), forKey: .startingTimeKey)
-        task.resume()
     }
 }
-// codebeat:enable[ARITY]
 
 internal extension DropboxFileProvider {
     static let dateFormatter = DateFormatter()

Sources/ExtendedLocalFileProvider.swift

@@ -129,14 +129,14 @@ public struct LocalFileInformationGenerator {
     
     /// Audio and music extensions supportes for thumbnail.
     ///
-    /// Default: `["mp3", "aac", "m4a"]`
-    static public var audioThumbnailExtensions: [String]  = ["mp3", "aac", "m4a"]
+    /// Default: `["mp1", "mp2", "mp3", "mpa", "mpga", "m1a", "m2a", "m4a", "m4b", "m4p", "m4r", "aac", "snd", "caf", "aa", "aax", "adts", "aif", "aifc", "aiff", "au", "flac", "amr", "wav", "wave", "bwf", "ac3", "eac3", "ec3", "cdda"]`
+    static public var audioThumbnailExtensions: [String]  = ["mp1", "mp2", "mp3", "mpa", "mpga", "m1a", "m2a", "m4a", "m4b", "m4p", "m4r", "aac", "snd", "caf", "aa", "aax", "adts", "aif", "aifc", "aiff", "au", "flac", "amr", "wav", "wave", "bwf", "ac3", "eac3", "ec3", "cdda"]
     
     /// Video extensions supportes for thumbnail.
     ///
-    /// Default: `["mov", "mp4", "m4v", "mpg", "mpeg"]`
-    static public var videoThumbnailExtensions: [String]  = ["mov", "mp4", "m4v", "mpg", "mpeg"]
-    
+    /// Default: `["mov", "mp4", "mpg4", "m4v", "mqv", "mpg", "mpeg", "avi", "vfw", "3g2", "3gp", "3gp2", "3gpp", "qt"]`
+    static public var videoThumbnailExtensions: [String]  = ["mov", "mp4", "mpg4", "m4v", "mqv", "mpg", "mpeg", "avi", "vfw", "3g2", "3gp", "3gp2", "3gpp", "qt"]
+
     /// Portable document file extensions supportes for thumbnail.
     ///
     /// Default: `["pdf"]`
@@ -160,13 +160,13 @@ public struct LocalFileInformationGenerator {
     
     /// Audio and music extensions supportes for properties.
     ///
-    /// Default: `["mp3", "aac", "m4a", "caf"]`
-    static public var audioPropertiesExtensions: [String]   = ["mp3", "aac", "m4a", "caf"]
+    /// Default: `["mp1", "mp2", "mp3", "mpa", "mpga", "m1a", "m2a", "m4a", "m4b", "m4p", "m4r", "aac", "snd", "caf", "aa", "aax", "adts", "aif", "aifc", "aiff", "au", "flac", "amr", "wav", "wave", "bwf", "ac3", "eac3", "ec3", "cdda"]`
+    static public var audioPropertiesExtensions: [String]   = ["mp1", "mp2", "mp3", "mpa", "mpga", "m1a", "m2a", "m4a", "m4b", "m4p", "m4r", "aac", "snd", "caf", "aa", "aax", "adts", "aif", "aifc", "aiff", "au", "flac", "amr", "wav", "wave", "bwf", "ac3", "eac3", "ec3", "cdda"]
     
     /// Video extensions supportes for properties.
     ///
-    /// Default: `["mp4", "mpg", "3gp", "mov", "avi"]`
-    static public var videoPropertiesExtensions: [String]   = ["mp4", "mpg", "3gp", "mov", "avi"]
+    /// Default: `["mov", "mp4", "mpg4", "m4v", "mqv", "mpg", "mpeg", "avi", "vfw", "3g2", "3gp", "3gp2", "3gpp", "qt"]`
+    static public var videoPropertiesExtensions: [String]   = ["mov", "mp4", "mpg4", "m4v", "mqv", "mpg", "mpeg", "avi", "vfw", "3g2", "3gp", "3gp2", "3gpp", "qt"]
     
     /// Portable document file extensions supportes for properties.
     ///

Sources/FTPFileProvider.swift

@@ -15,7 +15,9 @@ import Foundation
 open class FTPFileProvider: FileProviderBasicRemote, FileProviderOperations, FileProviderReadWrite {
     open class var type: String { return "FTP" }
     open let baseURL: URL?
-    open var currentPath: String
+    /// **OBSOLETED** Current active path used in `contentsOfDirectory(path:completionHandler:)` method.
+    @available(*, obsoleted: 0.22, message: "This property is redundant with almost no use internally.")
+    open var currentPath: String = ""
     
     open var dispatch_queue: DispatchQueue
     open var operation_queue: OperationQueue {
@@ -88,7 +90,6 @@ open class FTPFileProvider: FileProviderBasicRemote, FileProviderOperations, Fil
         
         self.baseURL =  (urlComponents.url!.path.hasSuffix("/") ? urlComponents.url! : urlComponents.url!.appendingPathComponent("")).absoluteURL
         self.passiveMode = passive
-        self.currentPath = ""
         self.useCache = false
         self.validatingCache = true
         self.cache = cache
@@ -107,7 +108,6 @@ open class FTPFileProvider: FileProviderBasicRemote, FileProviderOperations, Fil
     public required convenience init?(coder aDecoder: NSCoder) {
         guard let baseURL = aDecoder.decodeObject(forKey: "baseURL") as? URL else { return nil }
         self.init(baseURL: baseURL, passive: aDecoder.decodeBool(forKey: "passiveMode"), credential: aDecoder.decodeObject(forKey: "credential") as? URLCredential)
-        self.currentPath     = aDecoder.decodeObject(forKey: "currentPath") as? String ?? ""
         self.useCache        = aDecoder.decodeBool(forKey: "useCache")
         self.validatingCache = aDecoder.decodeBool(forKey: "validatingCache")
         self.useAppleImplementation = aDecoder.decodeBool(forKey: "useAppleImplementation")
@@ -116,7 +116,6 @@ open class FTPFileProvider: FileProviderBasicRemote, FileProviderOperations, Fil
     public func encode(with aCoder: NSCoder) {
         aCoder.encode(self.baseURL, forKey: "baseURL")
         aCoder.encode(self.credential, forKey: "credential")
-        aCoder.encode(self.currentPath, forKey: "currentPath")
         aCoder.encode(self.useCache, forKey: "useCache")
         aCoder.encode(self.validatingCache, forKey: "validatingCache")
         aCoder.encode(self.useAppleImplementation, forKey: "useAppleImplementation")
@@ -129,7 +128,6 @@ open class FTPFileProvider: FileProviderBasicRemote, FileProviderOperations, Fil
     
     open func copy(with zone: NSZone? = nil) -> Any {
         let copy = FTPFileProvider(baseURL: self.baseURL!, credential: self.credential, cache: self.cache)!
-        copy.currentPath = self.currentPath
         copy.delegate = self.delegate
         copy.fileOperationDelegate = self.fileOperationDelegate
         copy.useCache = self.useCache
@@ -315,7 +313,7 @@ open class FTPFileProvider: FileProviderBasicRemote, FileProviderOperations, Fil
     }
     
     open func url(of path: String?) -> URL {
-        let path = (path ?? self.currentPath).trimmingCharacters(in: CharacterSet(charactersIn: "/ ")).addingPercentEncoding(withAllowedCharacters: .filePathAllowed) ?? (path ?? self.currentPath)
+        let path = path?.trimmingCharacters(in: CharacterSet(charactersIn: "/ ")).addingPercentEncoding(withAllowedCharacters: .filePathAllowed) ?? (path ?? "")
         
         var baseUrlComponent = URLComponents(url: self.baseURL!, resolvingAgainstBaseURL: true)
         baseUrlComponent?.user = credential?.user

Sources/FTPHelper.swift

@@ -789,20 +789,14 @@ internal extension FTPFileProvider {
     }
     
     func ftpPath(_ apath: String) -> String {
-        var path = apath.isEmpty ? self.currentPath : apath
-        
         // path of base url should be concreted into file path! And remove final slash
-        path = baseURL!.appendingPathComponent(path).path.replacingOccurrences(of: "/", with: "", options: [.anchored, .backwards])
+        var path = baseURL!.appendingPathComponent(apath).path.replacingOccurrences(of: "/", with: "", options: [.anchored, .backwards])
         
         // Fixing slashes
         if !path.hasPrefix("/") {
             path = "/" + path
         }
         
-        if path.isEmpty {
-            path = "/"
-        }
-        
         return path
     }
     

Sources/FileProvider.swift

@@ -29,10 +29,6 @@ public protocol FileProviderBasic: class, NSSecureCoding {
     /// The url of which paths should resolve against.
     var baseURL: URL? { get }
     
-    /// **DEPRECATED** Current active path used in `contentsOfDirectory(path:completionHandler:)` method.
-    @available(*, deprecated, message: "This property is redundant with almost no use internally.")
-    var currentPath: String { get set }
-    
     /**
      Dispatch queue usually used in query methods.
      Set it to a new object to switch between cuncurrent and serial queues.

Sources/HTTPFileProvider.swift

@@ -17,7 +17,10 @@ import Foundation
 open class HTTPFileProvider: FileProviderBasicRemote, FileProviderOperations, FileProviderReadWrite {
     open class var type: String { fatalError("HTTPFileProvider is an abstract class. Please implement \(#function) in subclass.") }
     open let baseURL: URL?
-    open var currentPath: String
+    
+    /// **OBSOLETED** Current active path used in `contentsOfDirectory(path:completionHandler:)` method.
+    @available(*, obsoleted: 0.22, message: "This property is redundant with almost no use internally.")
+    open var currentPath: String = ""
     
     open var dispatch_queue: DispatchQueue
     open var operation_queue: OperationQueue {
@@ -84,7 +87,6 @@ open class HTTPFileProvider: FileProviderBasicRemote, FileProviderOperations, Fi
      */
     public init(baseURL: URL?, credential: URLCredential?, cache: URLCache?) {
         self.baseURL = baseURL
-        self.currentPath = ""
         self.useCache = false
         self.validatingCache = true
         self.cache = cache
@@ -107,7 +109,6 @@ open class HTTPFileProvider: FileProviderBasicRemote, FileProviderOperations, Fi
     public func encode(with aCoder: NSCoder) {
         aCoder.encode(self.baseURL, forKey: "baseURL")
         aCoder.encode(self.credential, forKey: "credential")
-        aCoder.encode(self.currentPath, forKey: "currentPath")
         aCoder.encode(self.useCache, forKey: "useCache")
         aCoder.encode(self.validatingCache, forKey: "validatingCache")
     }
@@ -317,6 +318,46 @@ open class HTTPFileProvider: FileProviderBasicRemote, FileProviderOperations, Fi
         return progress
     }
     
+    internal func paginated(_ path: String, startToken: String? = nil, currentProgress: Progress? = nil, previousResult: [FileObject] = [], requestHandler: @escaping (_ token: String?) -> URLRequest?, pageHandler: @escaping (_ data: Data?, _ progress: Progress) -> (files: [FileObject], error: Error?, newToken: String?), completionHandler: @escaping (_ contents: [FileObject], _ error: Error?) -> Void) -> Progress {
+        let progress = currentProgress ?? Progress(totalUnitCount: -1)
+        if progress.isCancelled { return progress }
+        
+        guard let request = requestHandler(startToken) else {
+            return progress
+        }
+        
+        let task = session.dataTask(with: request, completionHandler: { (data, response, error) in
+            if let error = error {
+                completionHandler(previousResult, error)
+                return
+            }
+            if let code = (response as? HTTPURLResponse)?.statusCode , code >= 300, let rCode = FileProviderHTTPErrorCode(rawValue: code) {
+                let responseError = self.serverError(with: rCode, path: path, data: data)
+                completionHandler(previousResult, responseError)
+                return
+            }
+            
+            let (newFiles, err, newToken) = pageHandler(data, progress)
+            if let error = err {
+                completionHandler(previousResult, error)
+                return
+            }
+            let files = previousResult + newFiles
+            if let newToken = newToken, !progress.isCancelled {
+                _ = self.paginated(path, startToken: newToken, currentProgress: progress, previousResult: files, requestHandler: requestHandler, pageHandler: pageHandler, completionHandler: completionHandler)
+            } else {
+                completionHandler(files, nil)
+            }
+            
+        })
+        progress.cancellationHandler = { [weak task] in
+            task?.cancel()
+        }
+        progress.setUserInfoObject(Date(), forKey: .startingTimeKey)
+        task.resume()
+        return progress
+    }
+    
     internal func upload_simple(_ targetPath: String, request: URLRequest, data: Data? = nil, localFile: URL? = nil, operation: FileOperationType, completionHandler: SimpleCompletionHandler) -> Progress? {
         let size = data?.count ?? Int((try? localFile?.resourceValues(forKeys: [.fileSizeKey]))??.fileSize ?? -1)
         

Sources/LocalFileProvider.swift

@@ -17,7 +17,9 @@ import Foundation
 open class LocalFileProvider: FileProvider, FileProviderMonitor, FileProvideUndoable {
     open class var type: String { return "Local" }
     open fileprivate(set) var baseURL: URL?
-    open var currentPath: String
+    /// **OBSOLETED** Current active path used in `contentsOfDirectory(path:completionHandler:)` method.
+    @available(*, obsoleted: 0.22, message: "This property is redundant with almost no use internally.")
+    open var currentPath: String = ""
     open var dispatch_queue: DispatchQueue
     open var operation_queue: OperationQueue
     open weak var delegate: FileProviderDelegate?
@@ -99,7 +101,6 @@ open class LocalFileProvider: FileProvider, FileProviderMonitor, FileProvideUndo
             fatalError("Cannot initialize a Local provider from remote URL.")
         }
         self.baseURL = (baseURL.absoluteString.hasSuffix("/") ? baseURL : baseURL.appendingPathComponent("")).absoluteURL
-        self.currentPath = ""
         self.credential = nil
         self.isCoorinating = false
         
@@ -121,13 +122,11 @@ open class LocalFileProvider: FileProvider, FileProviderMonitor, FileProvideUndo
             return nil
         }
         self.init(baseURL: baseURL)
-        self.currentPath   = aDecoder.decodeObject(forKey: "currentPath") as? String ?? ""
         self.isCoorinating = aDecoder.decodeBool(forKey: "isCoorinating")
     }
     
     open func encode(with aCoder: NSCoder) {
         aCoder.encode(self.baseURL, forKey: "currentPath")
-        aCoder.encode(self.currentPath, forKey: "currentPath")
         aCoder.encode(self.isCoorinating, forKey: "isCoorinating")
     }
     
@@ -137,7 +136,6 @@ open class LocalFileProvider: FileProvider, FileProviderMonitor, FileProvideUndo
     
     public func copy(with zone: NSZone? = nil) -> Any {
         let copy = LocalFileProvider(baseURL: self.baseURL!)
-        copy.currentPath = self.currentPath
         copy.undoManager = self.undoManager
         copy.isCoorinating = self.isCoorinating
         copy.delegate = self.delegate

Sources/OneDriveFileProvider.swift

@@ -139,7 +139,6 @@ open class OneDriveFileProvider: HTTPFileProvider, FileProviderSharing {
         self.init(credential: aDecoder.decodeObject(forKey: "credential") as? URLCredential,
                   serverURL: aDecoder.decodeObject(forKey: "baseURL") as? URL,
                   subAddress: subAddress)
-        self.currentPath   = aDecoder.decodeObject(forKey: "currentPath") as? String ?? ""
         self.useCache = aDecoder.decodeBool(forKey: "useCache")
         self.validatingCache = aDecoder.decodeBool(forKey: "validatingCache")
     }
@@ -151,7 +150,6 @@ open class OneDriveFileProvider: HTTPFileProvider, FileProviderSharing {
     
     open override func copy(with zone: NSZone? = nil) -> Any {
         let copy = OneDriveFileProvider(credential: self.credential, serverURL: self.baseURL, subAddress: self.subAddress, cache: self.cache)
-        copy.currentPath = self.currentPath
         copy.delegate = self.delegate
         copy.fileOperationDelegate = self.fileOperationDelegate
         copy.useCache = self.useCache
@@ -160,9 +158,29 @@ open class OneDriveFileProvider: HTTPFileProvider, FileProviderSharing {
     }
     
     open override func contentsOfDirectory(path: String, completionHandler: @escaping (_ contents: [FileObject], _ error: Error?) -> Void) {
-        list(path) { (contents, cursor, error) in
-            completionHandler(contents, error)
-        }
+        _ = paginated(path, requestHandler: { [weak self] (token) -> URLRequest? in
+            guard let `self` = self else { return nil }
+            let url = token.flatMap(URL.init(string:)) ?? self.url(of: path, modifier: "children")
+            var request = URLRequest(url: url)
+            request.httpMethod = "GET"
+            request.set(httpAuthentication: self.credential, with: .oAuth2)
+            return request
+        }, pageHandler: { [weak self] (data, _) -> (files: [FileObject], error: Error?, newToken: String?) in
+            guard let `self` = self else { return ([], nil, nil) }
+            
+            guard let json = data?.deserializeJSON(), let entries = json["value"] as? [AnyObject] else {
+                let err = self.urlError(path, code: .badServerResponse)
+                return ([], err, nil)
+            }
+            
+            var files = [FileObject]()
+            for entry in entries {
+                if let entry = entry as? [String: AnyObject], let file = OneDriveFileObject(baseURL: self.baseURL, subAddress: self.subAddress, json: entry) {
+                    files.append(file)
+                }
+            }
+            return (files, nil, json["@odata.nextLink"] as? String)
+        }, completionHandler: completionHandler)
     }
     
     open override func attributesOfItem(path: String, completionHandler: @escaping (_ attributes: FileObject?, _ error: Error?) -> Void) {
@@ -206,21 +224,45 @@ open class OneDriveFileProvider: HTTPFileProvider, FileProviderSharing {
     }
     
     open override func searchFiles(path: String, recursive: Bool, query: NSPredicate, foundItemHandler: ((FileObject) -> Void)?, completionHandler: @escaping (_ files: [FileObject], _ error: Error?) -> Void) -> Progress? {
-        var foundFiles = [OneDriveFileObject]()
-        var queryStr: String?
-        queryStr = query.findValue(forKey: "name") as? String ?? query.findAllValues(forKey: nil).flatMap { $0.value as? String }.first
-        guard let finalQueryStr = queryStr else { return nil }
-        let progress = Progress(totalUnitCount: -1)
-        progress.setUserInfoObject(url(of: path), forKey: .fileURLKey)
-        search(path, query: finalQueryStr, recursive: recursive, progress: progress, foundItem: { (file) in
-            if query.evaluate(with: file.mapPredicate()) {
-                foundFiles.append(file)
-                foundItemHandler?(file)
+        let queryStr = query.findValue(forKey: "name") as? String ?? query.findAllValues(forKey: nil).flatMap { $0.value as? String }.first
+        
+        return paginated(path, requestHandler: { [weak self] (token) -> URLRequest? in
+            guard let `self` = self else { return nil }
+            
+            let url: URL
+            if let next = token.flatMap(URL.init(string:)) {
+                url = next
+            } else {
+                let bURL = self.baseURL!.appendingPathComponent(self.subAddress.drivePath).appendingPathComponent("root/search")
+                var components = URLComponents(url: bURL, resolvingAgainstBaseURL: false)!
+                let qItem = URLQueryItem(name: "q", value: (queryStr ?? "*"))
+                components.queryItems = [qItem]
+                if recursive {
+                    components.queryItems?.append(URLQueryItem(name: "expand", value: "children"))
+                }
+                url = components.url!
             }
-        }, completionHandler: { (error) in
-            completionHandler(foundFiles, error)
-        })
-        return progress
+            
+            var request = URLRequest(url: url)
+            request.httpMethod = "GET"
+            return request
+        }, pageHandler: { [weak self] (data, progress) -> (files: [FileObject], error: Error?, newToken: String?) in
+            guard let `self` = self else { return ([], nil, nil) }
+            guard let json = data?.deserializeJSON(), let entries = json["value"] as? [AnyObject] else {
+                let err = self.urlError(path, code: .badServerResponse)
+                return ([], err, nil)
+            }
+            
+            var foundFiles = [FileObject]()
+            for entry in entries {
+                if let entry = entry as? [String: AnyObject], let file = OneDriveFileObject(baseURL: self.baseURL, subAddress: self.subAddress, json: entry), query.evaluate(with: file.mapPredicate()) {
+                    foundFiles.append(file)
+                    foundItemHandler?(file)
+                }
+            }
+            
+            return (foundFiles, nil, json["@odata.nextLink"] as? String)
+        }, completionHandler: completionHandler)
     }
     
     open func url(of path: String, modifier: String? = nil) -> URL {

Sources/OneDriveHelper.swift

@@ -90,95 +90,6 @@ public final class OneDriveFileObject: FileObject {
     }
 }
 
-// codebeat:disable[ARITY]
-internal extension OneDriveFileProvider {
-    func list(_ path: String, cursor: URL? = nil, prevContents: [OneDriveFileObject] = [], completionHandler: @escaping ((_ contents: [FileObject], _ cursor: String?, _ error: Error?) -> Void)) {
-        let url = cursor ?? self.url(of: path, modifier: "children")
-        var request = URLRequest(url: url)
-        request.httpMethod = "GET"
-        request.set(httpAuthentication: credential, with: .oAuth2)
-        let task = session.dataTask(with: request, completionHandler: { (data, response, error) in
-            var responseError: FileProviderHTTPError?
-            var files = prevContents
-            if let code = (response as? HTTPURLResponse)?.statusCode , code >= 300, let rCode = FileProviderHTTPErrorCode(rawValue: code) {
-                responseError = self.serverError(with: rCode, path: path, data: data)
-            }
-            if let json = data?.deserializeJSON() {
-                if let entries = json["value"] as? [AnyObject] , entries.count > 0 {
-                    for entry in entries {
-                        if let entry = entry as? [String: AnyObject], let file = OneDriveFileObject(baseURL: self.baseURL, subAddress: self.subAddress, json: entry) {
-                            files.append(file)
-                        }
-                    }
-                    let ncursor: URL? = (json["@odata.nextLink"] as? String).flatMap { URL(string: $0) }
-                    let hasmore = ncursor != nil
-                    if hasmore {
-                        self.list(path, cursor: ncursor, prevContents: files, completionHandler: completionHandler)
-                        return
-                    }
-                }
-            }
-            completionHandler(files, nil, responseError ?? error)
-        })
-        task.taskDescription = FileOperationType.fetch(path: path).json
-        task.resume()
-    }
-    
-    func search(_ startPath: String = "", query: String, recursive: Bool, next: URL? = nil, progress: Progress, foundItem: @escaping ((_ file: OneDriveFileObject) -> Void), completionHandler: @escaping ((_ error: Error?) -> Void)) {
-        if progress.isCancelled {
-            return
-        }
-        
-        let url: URL
-        if let next = next {
-            url = next
-        } else {
-            let bURL = self.baseURL!.appendingPathComponent(subAddress.drivePath).appendingPathComponent("root/search")
-            var components = URLComponents(url: bURL, resolvingAgainstBaseURL: false)!
-            let qItem = URLQueryItem(name: "q", value: query)
-            components.queryItems = [qItem]
-            if recursive {
-                components.queryItems?.append(URLQueryItem(name: "expand", value: "children"))
-            }
-            url = components.url!
-        }
-        
-        var request = URLRequest(url: url)
-        request.httpMethod = "GET"
-        request.set(httpAuthentication: credential, with: .oAuth2)
-        
-        let task = session.dataTask(with: request, completionHandler: { (data, response, error) in
-            var responseError: FileProviderHTTPError?
-            if let code = (response as? HTTPURLResponse)?.statusCode , code >= 300, let rCode = FileProviderHTTPErrorCode(rawValue: code) {
-                responseError = self.serverError(with: rCode, path: startPath, data: data)
-            }
-            if let json = data?.deserializeJSON() {
-                if let entries = json["value"] as? [AnyObject] , entries.count > 0 {
-                    for entry in entries {
-                        if let entry = entry as? [String: AnyObject], let file = OneDriveFileObject(baseURL: self.baseURL, subAddress: self.subAddress, json: entry) {
-                            foundItem(file)
-                        }
-                    }
-                    let next: URL? = (json["@odata.nextLink"] as? String).flatMap { URL(string: $0) }
-                    if !progress.isCancelled, let next = next {
-                        self.search(startPath, query: query, recursive: recursive, next: next, progress: progress, foundItem: foundItem, completionHandler: completionHandler)
-                    } else {
-                        completionHandler(responseError ?? error)
-                    }
-                    return
-                }
-            }
-            completionHandler(responseError ?? error)
-        })
-        progress.cancellationHandler = { [weak task] in
-            task?.cancel()
-        }
-        progress.setUserInfoObject(Date(), forKey: .startingTimeKey)
-        task.resume()
-    }
-}
-// codebeat:enable[ARITY]
-
 internal extension OneDriveFileProvider {
     static let dateFormatter = DateFormatter()
     static let decimalFormatter = NumberFormatter()

Sources/WebDAVFileProvider.swift

@@ -49,14 +49,12 @@ open class WebDAVFileProvider: HTTPFileProvider, FileProviderSharing {
         }
         self.init(baseURL: baseURL,
                   credential: aDecoder.decodeObject(forKey: "credential") as? URLCredential)
-        self.currentPath   = aDecoder.decodeObject(forKey: "currentPath") as? String ?? ""
         self.useCache        = aDecoder.decodeBool(forKey: "useCache")
         self.validatingCache = aDecoder.decodeBool(forKey: "validatingCache")
     }
     
     override open func copy(with zone: NSZone? = nil) -> Any {
         let copy = WebDAVFileProvider(baseURL: self.baseURL!, credential: self.credential, cache: self.cache)!
-        copy.currentPath = self.currentPath
         copy.delegate = self.delegate
         copy.fileOperationDelegate = self.fileOperationDelegate
         copy.useCache = self.useCache