SessionDelegate Class Reference

URLSessionDelegate Overrides

sessionDidBecomeInvalidWithError
Overrides default behavior for URLSessionDelegate method urlSession(_:didBecomeInvalidWithError:).
Declaration
Swift

open var sessionDidBecomeInvalidWithError: ((URLSession, Error?) -> Void)?


                    
                    
                    sessionDidReceiveChallenge

Overrides default behavior for URLSessionDelegate method urlSession(_:didReceive:completionHandler:).

Declaration

Swift

open var sessionDidReceiveChallenge: ((URLSession, URLAuthenticationChallenge) -> (URLSession.AuthChallengeDisposition, URLCredential?))?

sessionDidReceiveChallengeWithCompletion
Overrides all behavior for URLSessionDelegate method urlSession(_:didReceive:completionHandler:) and requires the caller to call the completionHandler.
Declaration
Swift

open var sessionDidReceiveChallengeWithCompletion: ((URLSession, URLAuthenticationChallenge, @escaping (URLSession.AuthChallengeDisposition, URLCredential?) -> Void) -> Void)?
sessionDidFinishEventsForBackgroundURLSession
Overrides default behavior for URLSessionDelegate method urlSessionDidFinishEvents(forBackgroundURLSession:).
Declaration
Swift

open var sessionDidFinishEventsForBackgroundURLSession: ((URLSession) -> Void)?

URLSessionTaskDelegate Overrides

taskWillPerformHTTPRedirection
Overrides default behavior for URLSessionTaskDelegate method urlSession(_:task:willPerformHTTPRedirection:newRequest:completionHandler:).
Declaration
Swift

open var taskWillPerformHTTPRedirection: ((URLSession, URLSessionTask, HTTPURLResponse, URLRequest) -> URLRequest?)?
taskWillPerformHTTPRedirectionWithCompletion
Overrides all behavior for URLSessionTaskDelegate method urlSession(_:task:willPerformHTTPRedirection:newRequest:completionHandler:) and requires the caller to call the completionHandler.
Declaration
Swift

open var taskWillPerformHTTPRedirectionWithCompletion: ((URLSession, URLSessionTask, HTTPURLResponse, URLRequest, @escaping (URLRequest?) -> Void) -> Void)?


                    
                    
                    taskDidReceiveChallenge

Overrides default behavior for URLSessionTaskDelegate method urlSession(_:task:didReceive:completionHandler:).

Declaration

Swift

open var taskDidReceiveChallenge: ((URLSession, URLSessionTask, URLAuthenticationChallenge) -> (URLSession.AuthChallengeDisposition, URLCredential?))?

taskDidReceiveChallengeWithCompletion
Overrides all behavior for URLSessionTaskDelegate method urlSession(_:task:didReceive:completionHandler:) and requires the caller to call the completionHandler.
Declaration
Swift

open var taskDidReceiveChallengeWithCompletion: ((URLSession, URLSessionTask, URLAuthenticationChallenge, @escaping (URLSession.AuthChallengeDisposition, URLCredential?) -> Void) -> Void)?
taskNeedNewBodyStream
Overrides default behavior for URLSessionTaskDelegate method urlSession(_:task:needNewBodyStream:).
Declaration
Swift

open var taskNeedNewBodyStream: ((URLSession, URLSessionTask) -> InputStream?)?
taskNeedNewBodyStreamWithCompletion
Overrides all behavior for URLSessionTaskDelegate method urlSession(_:task:needNewBodyStream:) and requires the caller to call the completionHandler.
Declaration
Swift

open var taskNeedNewBodyStreamWithCompletion: ((URLSession, URLSessionTask, @escaping (InputStream?) -> Void) -> Void)?
taskDidSendBodyData
Overrides default behavior for URLSessionTaskDelegate method urlSession(_:task:didSendBodyData:totalBytesSent:totalBytesExpectedToSend:).
Declaration
Swift

open var taskDidSendBodyData: ((URLSession, URLSessionTask, Int64, Int64, Int64) -> Void)?
taskDidComplete
Overrides default behavior for URLSessionTaskDelegate method urlSession(_:task:didCompleteWithError:).
Declaration
Swift

open var taskDidComplete: ((URLSession, URLSessionTask, Error?) -> Void)?

URLSessionDataDelegate Overrides

dataTaskDidReceiveResponse
Overrides default behavior for URLSessionDataDelegate method urlSession(_:dataTask:didReceive:completionHandler:).
Declaration
Swift

open var dataTaskDidReceiveResponse: ((URLSession, URLSessionDataTask, URLResponse) -> URLSession.ResponseDisposition)?
dataTaskDidReceiveResponseWithCompletion
Overrides all behavior for URLSessionDataDelegate method urlSession(_:dataTask:didReceive:completionHandler:) and requires caller to call the completionHandler.
Declaration
Swift

open var dataTaskDidReceiveResponseWithCompletion: ((URLSession, URLSessionDataTask, URLResponse, @escaping (URLSession.ResponseDisposition) -> Void) -> Void)?
dataTaskDidBecomeDownloadTask
Overrides default behavior for URLSessionDataDelegate method urlSession(_:dataTask:didBecome:).
Declaration
Swift

open var dataTaskDidBecomeDownloadTask: ((URLSession, URLSessionDataTask, URLSessionDownloadTask) -> Void)?
dataTaskDidReceiveData
Overrides default behavior for URLSessionDataDelegate method urlSession(_:dataTask:didReceive:).
Declaration
Swift

open var dataTaskDidReceiveData: ((URLSession, URLSessionDataTask, Data) -> Void)?
dataTaskWillCacheResponse
Overrides default behavior for URLSessionDataDelegate method urlSession(_:dataTask:willCacheResponse:completionHandler:).
Declaration
Swift

open var dataTaskWillCacheResponse: ((URLSession, URLSessionDataTask, CachedURLResponse) -> CachedURLResponse?)?
dataTaskWillCacheResponseWithCompletion
Overrides all behavior for URLSessionDataDelegate method urlSession(_:dataTask:willCacheResponse:completionHandler:) and requires caller to call the completionHandler.
Declaration
Swift

open var dataTaskWillCacheResponseWithCompletion: ((URLSession, URLSessionDataTask, CachedURLResponse, @escaping (CachedURLResponse?) -> Void) -> Void)?

URLSessionDownloadDelegate Overrides

downloadTaskDidFinishDownloadingToURL
Overrides default behavior for URLSessionDownloadDelegate method urlSession(_:downloadTask:didFinishDownloadingTo:).
Declaration
Swift

open var downloadTaskDidFinishDownloadingToURL: ((URLSession, URLSessionDownloadTask, URL) -> Void)?
downloadTaskDidWriteData
Overrides default behavior for URLSessionDownloadDelegate method urlSession(_:downloadTask:didWriteData:totalBytesWritten:totalBytesExpectedToWrite:).
Declaration
Swift

open var downloadTaskDidWriteData: ((URLSession, URLSessionDownloadTask, Int64, Int64, Int64) -> Void)?
downloadTaskDidResumeAtOffset
Overrides default behavior for URLSessionDownloadDelegate method urlSession(_:downloadTask:didResumeAtOffset:expectedTotalBytes:).
Declaration
Swift

open var downloadTaskDidResumeAtOffset: ((URLSession, URLSessionDownloadTask, Int64, Int64) -> Void)?

URLSessionStreamDelegate Overrides


                    
                    
                    streamTaskReadClosed

Overrides default behavior for URLSessionStreamDelegate method urlSession(_:readClosedFor:).

Declaration

Swift

@available(iOS 9.0, macOS 10.11, tvOS 9.0, *)
open var streamTaskReadClosed: ((URLSession, URLSessionStreamTask) -> Void)? { get set }


                    
                    
                    streamTaskWriteClosed

Overrides default behavior for URLSessionStreamDelegate method urlSession(_:writeClosedFor:).

Declaration

Swift

@available(iOS 9.0, macOS 10.11, tvOS 9.0, *)
open var streamTaskWriteClosed: ((URLSession, URLSessionStreamTask) -> Void)? { get set }


                    
                    
                    streamTaskBetterRouteDiscovered

Overrides default behavior for URLSessionStreamDelegate method urlSession(_:betterRouteDiscoveredFor:).

Declaration

Swift

@available(iOS 9.0, macOS 10.11, tvOS 9.0, *)
open var streamTaskBetterRouteDiscovered: ((URLSession, URLSessionStreamTask) -> Void)? { get set }


                    
                    
                    streamTaskDidBecomeInputAndOutputStreams

Overrides default behavior for URLSessionStreamDelegate method urlSession(_:streamTask:didBecome:outputStream:).

Declaration

Swift

@available(iOS 9.0, macOS 10.11, tvOS 9.0, *)
open var streamTaskDidBecomeInputAndOutputStreams: ((URLSession, URLSessionStreamTask, InputStream, OutputStream) -> Void)? { get set }

Properties

subscript(_:)
Access the task delegate for the specified task in a thread-safe manner.
Declaration
Swift

open subscript(task: URLSessionTask) -> Request? { get set }

Lifecycle

init()
Initializes the SessionDelegate instance.
Declaration
Swift

public override init()
Return Value

The new SessionDelegate instance.

NSObject Overrides


                    
                    
                    responds(to:)

Returns a Bool indicating whether the SessionDelegate implements or inherits a method that can respond to a specified message.

Declaration

Swift

open override func responds(to selector: Selector) -> Bool

Parameters


                                selector

A selector that identifies a message.

Return Value

true if the receiver implements or inherits a method that can respond to selector, otherwise false.

URLSessionDelegate


                    
                    
                    urlSession(_:didBecomeInvalidWithError:)

Tells the delegate that the session has been invalidated.

Declaration

Swift

open func urlSession(_ session: URLSession, didBecomeInvalidWithError error: Error?)

Parameters

`session`	The session object that was invalidated.
`error`	The error that caused invalidation, or nil if the invalidation was explicit.


                    
                    
                    urlSession(_:didReceive:completionHandler:)

Requests credentials from the delegate in response to a session-level authentication request from the remote server.

Declaration

Swift

open func urlSession(
	_ session: URLSession,
	didReceive challenge: URLAuthenticationChallenge,
	completionHandler: @escaping (URLSession.AuthChallengeDisposition, URLCredential?) -> Void)

Parameters

`session`	The session containing the task that requested authentication.
`challenge`	An object that contains the request for authentication.
`completionHandler`	A handler that your delegate method must call providing the disposition and credential.


                    
                    
                    urlSessionDidFinishEvents(forBackgroundURLSession:)

Tells the delegate that all messages enqueued for a session have been delivered.

Declaration

Swift

open func urlSessionDidFinishEvents(forBackgroundURLSession session: URLSession)

Parameters


                                session

The session that no longer has any outstanding requests.

URLSessionTaskDelegate


                    
                    
                    urlSession(_:task:willPerformHTTPRedirection:newRequest:completionHandler:)

Tells the delegate that the remote server requested an HTTP redirect.

Declaration

Swift

open func urlSession(
	_ session: URLSession,
	task: URLSessionTask,
	willPerformHTTPRedirection response: HTTPURLResponse,
	newRequest request: URLRequest,
	completionHandler: @escaping (URLRequest?) -> Void)

Parameters

`session`	The session containing the task whose request resulted in a redirect.
`task`	The task whose request resulted in a redirect.
`response`	An object containing the server’s response to the original request.
`request`	A URL request object filled out with the new location.
`completionHandler`	A closure that your handler should call with either the value of the request parameter, a modified URL request object, or NULL to refuse the redirect and return the body of the redirect response.


                    
                    
                    urlSession(_:task:didReceive:completionHandler:)

Requests credentials from the delegate in response to an authentication request from the remote server.

Declaration

Swift

open func urlSession(
	_ session: URLSession,
	task: URLSessionTask,
	didReceive challenge: URLAuthenticationChallenge,
	completionHandler: @escaping (URLSession.AuthChallengeDisposition, URLCredential?) -> Void)

Parameters

`session`	The session containing the task whose request requires authentication.
`task`	The task whose request requires authentication.
`challenge`	An object that contains the request for authentication.
`completionHandler`	A handler that your delegate method must call providing the disposition and credential.


                    
                    
                    urlSession(_:task:needNewBodyStream:)

Tells the delegate when a task requires a new request body stream to send to the remote server.

Declaration

Swift

open func urlSession(
	_ session: URLSession,
	task: URLSessionTask,
	needNewBodyStream completionHandler: @escaping (InputStream?) -> Void)

Parameters

`session`	The session containing the task that needs a new body stream.
`task`	The task that needs a new body stream.
`completionHandler`	A completion handler that your delegate method should call with the new body stream.


                    
                    
                    urlSession(_:task:didSendBodyData:totalBytesSent:totalBytesExpectedToSend:)

Periodically informs the delegate of the progress of sending body content to the server.

Declaration

Swift

open func urlSession(
	_ session: URLSession,
	task: URLSessionTask,
	didSendBodyData bytesSent: Int64,
	totalBytesSent: Int64,
	totalBytesExpectedToSend: Int64)

Parameters

`session`	The session containing the data task.
`task`	The data task.
`bytesSent`	The number of bytes sent since the last time this delegate method was called.
`totalBytesSent`	The total number of bytes sent so far.
`totalBytesExpectedToSend`	The expected length of the body data.


                    
                    
                    urlSession(_:task:didFinishCollecting:)

Tells the delegate that the session finished collecting metrics for the task.

Declaration

Swift

@available(iOS 10.0, macOS 10.12, tvOS 10.0, *)
@objc(URLSession:task:didFinishCollectingMetrics:)
open func urlSession(_ session: URLSession, task: URLSessionTask, didFinishCollecting metrics: URLSessionTaskMetrics)

Parameters

`session`	The session collecting the metrics.
`task`	The task whose metrics have been collected.
`metrics`	The collected metrics.


                    
                    
                    urlSession(_:task:didCompleteWithError:)

Tells the delegate that the task finished transferring data.

Declaration

Swift

open func urlSession(_ session: URLSession, task: URLSessionTask, didCompleteWithError error: Error?)

Parameters

`session`	The session containing the task whose request finished transferring data.
`task`	The task whose request finished transferring data.
`error`	If an error occurred, an error object indicating how the transfer failed, otherwise nil.

URLSessionDataDelegate


                    
                    
                    urlSession(_:dataTask:didReceive:completionHandler:)

Tells the delegate that the data task received the initial reply (headers) from the server.

Declaration

Swift

open func urlSession(
	_ session: URLSession,
	dataTask: URLSessionDataTask,
	didReceive response: URLResponse,
	completionHandler: @escaping (URLSession.ResponseDisposition) -> Void)

Parameters

`session`	The session containing the data task that received an initial reply.
`dataTask`	The data task that received an initial reply.
`response`	A URL response object populated with headers.
`completionHandler`	A completion handler that your code calls to continue the transfer, passing a constant to indicate whether the transfer should continue as a data task or should become a download task.


                    
                    
                    urlSession(_:dataTask:didBecome:)

Tells the delegate that the data task was changed to a download task.

Declaration

Swift

open func urlSession(
	_ session: URLSession,
	dataTask: URLSessionDataTask,
	didBecome downloadTask: URLSessionDownloadTask)

Parameters

`session`	The session containing the task that was replaced by a download task.
`dataTask`	The data task that was replaced by a download task.
`downloadTask`	The new download task that replaced the data task.


                    
                    
                    urlSession(_:dataTask:didReceive:)

Tells the delegate that the data task has received some of the expected data.

Declaration

Swift

open func urlSession(_ session: URLSession, dataTask: URLSessionDataTask, didReceive data: Data)

Parameters

`session`	The session containing the data task that provided data.
`dataTask`	The data task that provided data.
`data`	A data object containing the transferred data.


                    
                    
                    urlSession(_:dataTask:willCacheResponse:completionHandler:)

Asks the delegate whether the data (or upload) task should store the response in the cache.

Declaration

Swift

open func urlSession(
	_ session: URLSession,
	dataTask: URLSessionDataTask,
	willCacheResponse proposedResponse: CachedURLResponse,
	completionHandler: @escaping (CachedURLResponse?) -> Void)

Parameters

`session`	The session containing the data (or upload) task.
`dataTask`	The data (or upload) task.
`proposedResponse`	The default caching behavior. This behavior is determined based on the current caching policy and the values of certain received headers, such as the Pragma and Cache-Control headers.
`completionHandler`	A block that your handler must call, providing either the original proposed response, a modified version of that response, or NULL to prevent caching the response. If your delegate implements this method, it must call this completion handler; otherwise, your app leaks memory.

URLSessionDownloadDelegate


                    
                    
                    urlSession(_:downloadTask:didFinishDownloadingTo:)

Tells the delegate that a download task has finished downloading.

Declaration

Swift

open func urlSession(
	_ session: URLSession,
	downloadTask: URLSessionDownloadTask,
	didFinishDownloadingTo location: URL)

Parameters

`session`	The session containing the download task that finished.
`downloadTask`	The download task that finished.
`location`	A file URL for the temporary file. Because the file is temporary, you must either open the file for reading or move it to a permanent location in your app’s sandbox container directory before returning from this delegate method.


                    
                    
                    urlSession(_:downloadTask:didWriteData:totalBytesWritten:totalBytesExpectedToWrite:)

Periodically informs the delegate about the download’s progress.

Declaration

Swift

open func urlSession(
	_ session: URLSession,
	downloadTask: URLSessionDownloadTask,
	didWriteData bytesWritten: Int64,
	totalBytesWritten: Int64,
	totalBytesExpectedToWrite: Int64)

Parameters

`session`	The session containing the download task.
`downloadTask`	The download task.
`bytesWritten`	The number of bytes transferred since the last time this delegate method was called.
`totalBytesWritten`	The total number of bytes transferred so far.
`totalBytesExpectedToWrite`	The expected length of the file, as provided by the Content-Length header. If this header was not provided, the value is `NSURLSessionTransferSizeUnknown`.


                    
                    
                    urlSession(_:downloadTask:didResumeAtOffset:expectedTotalBytes:)

Tells the delegate that the download task has resumed downloading.

Declaration

Swift

open func urlSession(
	_ session: URLSession,
	downloadTask: URLSessionDownloadTask,
	didResumeAtOffset fileOffset: Int64,
	expectedTotalBytes: Int64)

Parameters

`session`	The session containing the download task that finished.
`downloadTask`	The download task that resumed. See explanation in the discussion.
`fileOffset`	If the file’s cache policy or last modified date prevents reuse of the existing content, then this value is zero. Otherwise, this value is an integer representing the number of bytes on disk that do not need to be retrieved again.
`expectedTotalBytes`	The expected length of the file, as provided by the Content-Length header. If this header was not provided, the value is NSURLSessionTransferSizeUnknown.

URLSessionStreamDelegate


                    
                    
                    urlSession(_:readClosedFor:)

Tells the delegate that the read side of the connection has been closed.

Declaration

Swift

open func urlSession(_ session: URLSession, readClosedFor streamTask: URLSessionStreamTask)

Parameters

`session`	The session.
`streamTask`	The stream task.


                    
                    
                    urlSession(_:writeClosedFor:)

Tells the delegate that the write side of the connection has been closed.

Declaration

Swift

open func urlSession(_ session: URLSession, writeClosedFor streamTask: URLSessionStreamTask)

Parameters

`session`	The session.
`streamTask`	The stream task.


                    
                    
                    urlSession(_:betterRouteDiscoveredFor:)

Tells the delegate that the system has determined that a better route to the host is available.

Declaration

Swift

open func urlSession(_ session: URLSession, betterRouteDiscoveredFor streamTask: URLSessionStreamTask)

Parameters

`session`	The session.
`streamTask`	The stream task.


                    
                    
                    urlSession(_:streamTask:didBecome:outputStream:)

Tells the delegate that the stream task has been completed and provides the unopened stream objects.

Declaration

Swift

open func urlSession(
	_ session: URLSession,
	streamTask: URLSessionStreamTask,
	didBecome inputStream: InputStream,
	outputStream: OutputStream)

Parameters

`session`	The session.
`streamTask`	The stream task.
`inputStream`	The new input stream.
`outputStream`	The new output stream.