Files API for PubNub Swift Native SDK

Note

The PubNub Swift 3.0 SDK contains many significant changes from the 2.x SDK, including breaking changes. Please refer to the PubNub Swift 3.0 Migration Guide for more details.

Allows users to upload and share files. You can upload any file of up to 5 MB in size. This feature is commonly used in social apps to share images, or in medical apps to share medical records for patients.

When a file is uploaded on a channel, it's stored and managed using a storage service, and associated with your key. Subscribers to that channel receive a file event which contains a file ID, filename, and optional description.

Send file

Description

Upload file / data to specified channel.

Method(s)

1. send(  _ content: FileUploadContent,  channel: String,  remoteFilename: String,  publishRequest: PublishFileRequest = PublishFileRequest(),  custom requestConfig: RequestConfiguration = RequestConfiguration(),  uploadTask: @escaping (HTTPFileUploadTask) -> Void,  completion: ((Result<(file: PubNubLocalFile, publishedAt: Timetoken), Error>) -> Void)? )
   

   Parameter	Type	Required	Default	Description
   content	FileUploadContent	Yes		The content to be uploaded.
   channel	String	Yes		The channel the file should be uploaded to.
   remoteFilename	String	Yes	nil	The name of the content when uploaded.
   publishRequest	PublishFileRequest	Optional	PublishFileRequest()	The request configuration object when the file is published to PubNub.
   custom	RequestConfiguration	Optional	RequestConfiguration	Custom configuration overrides when generating the File Upload URLRequest
   uploadTask	(HTTPFileUploadTask) -> Void	Optional	{ _ in }	The file upload task executing the upload; contains a reference to the actual URLSessionUploadTask.
   completion	((Result<(task: HTTPFileUploadTask, file: PubNubFile, publishedAt: Timetoken), Error>) -> Void)?	Optional		The async Resultof the method call.

   Details

   enum FileUploadContent: CustomStringConvertible, CustomDebugStringConvertible
     /// A URL to an existing file
     case file(url: URL)
   
     /// The raw content of a file and the content type that best describes it
     case data(_ data: Data, contentType: String?)
   
     /// A stream of data, the content type of that stream, and the total length of the stream in bytes
     case stream(_ stream: InputStream, contentType: String?, contentLength: Int)
   
   struct PublishFileRequest
     /// The optional message that will be include alongside the File information
     public var additionalMessage: JSONCodable? = nil
   
     /// If true the published message is stored in history.
     public var store: Bool? = nil
   
     /// Set a per message time to live in storage.
     public var ttl: Int? = nil
   
     /// Additional metadata to publish alongside the file
     public var meta: JSONCodable? = nil
   
     /// Custom configuration overrides for this request
     public var customRequestConfig: RequestConfiguration = RequestConfiguration()
   
   /// The uploadTask handler will respond with an instance of HTTPFileUploadTask
   class HTTPFileUploadTask
   
     /// The underlying URLSessionTask that is being processed
     var urlSessionTask: URLSessionTask { get }
   
     /// A representation of the overall task progress
     var progress: Progress { get }
   
     /// The background identifier of the URLSession that is processing this task
     var sessionIdentifier: String? { get }
   
     // An error object that indicates why the task failed
     var error: Error? { get }
   
     // The server's response to the currently active request
     var response: HTTPURLResponse? { get
   
     // The body of the response
     var responseData: Data? { get }
   

Basic Usage

let fileURL = URL(fileURLWithPath: "path/to/example.png")

pubnub.send(
 .file(url: fileURL),
 channel: "my_channel",
 remoteFilename: fileURL.lastPathComponent
) { (fileTask: HTTPFileUploadTask) in

  print("The task \(fileTask.task.taskIdentifier) has started uploading; no need to call `resume()`")
  print("If needed, the `URLSessionUploadTask` can be accessed with `fileTask.urlSessionTask`")
  print("You can use `fileTask.progress` to populate a  `UIProgressView`/`ProgressView` ")

} completion: { result in
  switch result {
  case let .success((newFile, publishedAt)):
    print("The file with an ID of \(newFile.fileId) was uploaded at \(publishedAt) timetoken) ")
  case let .failure(error):
    print("An error occurred while uploading the file: \(error.localizedDescription)")
  }
}

Returns

The uploadTask handler will respond with an instance of HTTPFileUploadTask.

class HTTPFileUploadTask

  /// The underlying URLSessionTask that is being processed
  var urlSessionTask: URLSessionTask { get }

  /// A representation of the overall task progress
  var progress: Progress { get }

  /// The background identifier of the URLSession that is processing this task
  var sessionIdentifier: String? { get }

  // An error object that indicates why the task failed
  var error: Error? { get }

  // The server's response to the currently active request
  var response: HTTPURLResponse? { get

  // The body of the response
  var responseData: Data? { get }

The completion handler will respond with a Result.

Success A Tuple containing the HTTPFileUploadTaskthat completed, the PubNubFile or PubNubLocalFile that was uploaded, and the Timetoken when it was published.

protocol PubNubLocalFile

  /// The local URL of the file
  var fileURL: URL { get set }

  /// If the local filenames change this can be used to track the remote filename
  var remoteFilename: String { get }

  /// The channel the file is associated with
  var channel: String { get }

  /// PubNub-generated ID for a file
  var fileId: String { get }

  /// User defined name for a file
  var filename: String { get }

  /// Size, in bytes, of the stored file
  var size: Int64 { get }

  /// The MIME Type of the file
  var contentType: String { get }

  /// ISO 8601 date and time the file was uploaded
  var createdDate: Date? { get set }

  /// Custom payload that can be used to store additional file details
  var custom: JSONCodable? { get set }

Failure An Error describing the failure.

List channel files

Description

Retrieve list of files uploaded to Channel.

Method(s)

1. func listFiles(     channel: String,     limit: UInt = 100,     next: String? = nil,     custom requestConfig: RequestConfiguration = RequestConfiguration(),     completion: ((Result<(files: [PubNubFile], next: String?), Error>) -> Void)? )
   

   Parameter	Type	Required	Default	Description
   channel	String	Yes		Channel to get list of files.
   limit	UInt	Optional	100	Number of files to return. Minimum value is 1, and maximum is 100.
   next	String?	Optional	nil	Previously-returned cursor bookmark for fetching the next page.
   custom	RequestConfiguration	Optional	RequestConfiguration()	Custom configuration overrides when generating the File Upload URLRequest
   completion	((Result<(files: [PubNubFile], next: String?), Error>) -> Void)?	Optional		The async Result of the method call

Basic Usage

pubnub.listFiles(
  channel: "my_channel"
) { result in
  case let .success(response):
    print("There are \(response.files.count) file(s) found")

    if let nextPage = response.next {
      print("The next page used for pagination: \(nextPage)")
    }
  case let .failure(error):
    print("An error occurred while fetching the file list: \(error.localizedDescription)")
}

Returns

The completion handler will respond with a Result:

Success A Tuple list of PubNubFile objects, and the next page identifier (if one exists).

protocol PubNubFile

  /// The channel the file is associated with
  var channel: String { get }

  /// PubNub-generated ID for a file
  var fileId: String { get }

  /// User defined name for a file
  var filename: String { get }

  /// Size, in bytes, of the stored file
  var size: Int64 { get }

  /// The MIME Type of the file
  var contentType: String { get }

  /// ISO 8601 date and time the file was uploaded
  var createdDate: Date? { get set }

  /// Custom payload that can be used to store additional file details
  var custom: JSONCodable? { get set }

Failure An Error describing the failure.

Get File Url

Description

Generate URL which can be used to download file from target Channel.

Method(s)

1. func generateFileDownloadURL(   channel: String,   fileId: String,   filename: String ) throws -> URL
   

   Parameter	Type	Required	Description
   channel	String	Yes	Name of channel to which the file has been uploaded.
   fileID	String	Yes	Unique file identifier which has been assigned during file upload
   filename	String	Yes	Name under which the uploaded file is stored.

Basic Usage

do {
  let downloadURL = try pubnub.generateFileDownloadURL(channel: file.channel, fileId: file.fileId, filename: file.filename)
} catch {
  print("The error the occurred generating the URL \(error.localizedDescription)")
}

Returns

The URL where the file can be downloaded.

Download file

Description

Download file from specified Channel.

Method(s)

1. func download(   file: PubNubFile,   toFileURL localFileURL: URL,   resumeData: Data? = nil,   downloadTask: @escaping (HTTPFileDownloadTask) -> Void,   completion: ((Result<(task: HTTPFileDownloadTask, file: PubNubLocalFile), Error>) -> Void)? )
   

   Parameter	Type	Required	Default	Description
   file	PubNubFile	Yes		The file that should be downloaded.
   toFileURL	URL	Yes		The file URL where the file should be downloaded to. This is NOT the URL returned from generateFileDownloadURL
   resumeData	Data?	Optional	nil	A data object that provides the data necessary to resume a download.
   downloadTask	(HTTPFileDownloadTask) -> Void	Optional	{ _ in }	The file upload task executing the upload; contains a reference to the actual URLSessionUploadTask
   completion	((Result<(task: HTTPFileDownloadTask, file: PubNubLocalFile), Error>) -> Void)?	Optional		The async Result of the method call.

Basic Usage

let requestFile = PubNubLocalFileBase(
  fileURL: URL(fileURLWithPath: "path/to/example.png"),
   channel: "my_channel",
   fileId: "fileId-from-PubNub",
   remoteFilename: "filename-from-PubNub"
)

pubnub.download(
  file: requestFile, toFileURL: requestFile.fileURL
) { (fileTask: HTTPFileDownloadTask) in

  print("The task \(fileTask.taskIdentifier) has started downloading; no need to call `resume()`")
  print("If needed, the `URLSessionUploadTask` can be accessed with `fileTask.urlSessionTask`")
  print("You can use `fileTask.progress` to populate a  `UIProgressView`/`ProgressView` ")

} completion: { result in
  switch result {
  case let .success(task, newFile):
    print("The file task \(task.taskIdentifier) downloaded successfully to \(newFile.fileURL), which might be different than \(requestFile.fileURL)")
    print("This also might mean that \(newFile.filename) could be different from \(newFile.remoteFilename)")

  case let .failure(error):
    print("An error occurred while downloading the file: \(error.localizedDescription)")
  }
}

Resume Download

Downloads can be paused and resumed at a later time under certain conditions. See Pausing and Resuming Downloads and cancel(byProducingResumeData:)

If you were given resumeData you can use the following example to try and resume your download; otherwise you can restart a new download.

let resumeData = /* See above documentation on ways you can obtain this data */

let requestFile = PubNubLocalFileBase(
  fileURL: URL(fileURLWithPath: "path/to/example.png"),
   channel: "my_channel",
   fileId: "fileId-from-PubNub",
   remoteFilename: "filename-from-PubNub"
)

pubnub.download(
  file: requestFile,
  toFileURL: requestFile.fileURL,
  resumeData: resumeData
) { (fileTask: HTTPFileDownloadTask) in

  print("The task \(fileTask.task.taskIdentifier) has started downloading; no need to call `resume()`")
  print("If needed, the `URLSessionUploadTask` can be accessed with `fileTask.urlSessionTask`")
  print("You can use `fileTask.progress` to populate a  `UIProgressView`/`ProgressView` ")

} completion: { [weak self] result in
  switch result {
  case let .success(task, newFile):
    print("The file task \(task.taskIdentifier) downloaded successfully to \(newFile.fileURL), which might be different than \(requestFile.fileURL)")
    print("This also might mean that \(newFile.filename) could be different from \(newFile.remoteFilename)")

  case let .failure(error):
    print("An error occurred while downloading the file: \(error.localizedDescription)")
  }
}

Custom URLSession

By default, the PubNub instance will use a background configured URLSession. This will allow the download to continue while the application is not in the foreground. For more information, see Apple's documentation on Downloading Files in the Background

// Explicitly invalidate any existing tasks to avoid memory leaks when overwriting
pubnub.fileURLSession.invalidateAndCancel()

// Create and make any changes to the default configuration
// Use `URLSessionConfiguration.background(withIdentifier:)`` to create a default background configuration
let configuration = URLSessionConfiguration()

// Create the URLSession using the FileSessionManager as the delegate
pubnub.fileURLSession = URLSession(configuration: configuration, delegate: FileSessionManager(), delegateQueue: nil)

let requestFile = PubNubLocalFileBase(
  fileURL: URL(fileURLWithPath: "path/to/example.png"),
   channel: "my_channel",
   fileId: "fileId-from-PubNub",
   remoteFilename: "filename-from-PubNub"
)

pubnub.download(
  file: requestFile, toFileURL: requestFile.fileURL
) { (fileTask: HTTPFileDownloadTask) in

  print("The task \(fileTask.task.taskIdentifier) has started downloading; no need to call `resume()`")
  print("If needed, the `URLSessionUploadTask` can be accessed with `fileTask.urlSessionTask`")
  print("You can use `fileTask.progress` to populate a  `UIProgressView`/`ProgressView` ")

} completion: { result in
  switch result {
  case let .success(task, newFile):
    print("The file task \(task.taskIdentifier) downloaded successfully to \(newFile.fileURL), which might be different than \(requestFile.fileURL)")
    print("This also might mean that \(newFile.filename) could be different from \(newFile.remoteFilename)")

  case let .failure(error):
    print("An error occurred while downloading the file: \(error.localizedDescription)")
  }
}

Returns

The downloadTask handler will respond with an instance of HTTPFileUploadTask:

class HTTPFileDownloadTask

  /// The underlying URLSessionTask that is being processed
  var urlSessionTask: URLSessionTask { get }

  /// A representation of the overall task progress
  var progress: Progress { get }

  /// The background identifier of the URLSession that is processing this task
  var sessionIdentifier: String? { get }

  /// An error object that indicates why the task failed
  var error: Error? { get }

  /// The server's response to the currently active request
  var response: HTTPURLResponse? { get

  /// The location where the temporary downloaded file should be copied
  var destinationURL: URL { get }

The completion handler will respond with an instance of Result:

Success A Tuple containing the HTTPFileUploadTaskthat completed and the PubNubLocalFile that was downloaded. The fileURL of this object might be different from the toFileURL in the request if a file already exists at that location.

protocol PubNubLocalFile

  /// The local URL of the file
  var fileURL: URL { get set }

  /// If the local filename changes this can be used to track the remote filename
  var remoteFilename: String { get }

  /// The channel the file is associated with
  var channel: String { get }

  /// PubNub-generated ID for a file
  var fileId: String { get }

  /// User defined name for a file
  var filename: String { get }

  /// Size, in bytes, of the stored file
  var size: Int64 { get }

  /// The MIME Type of the file
  var contentType: String { get }

  /// ISO 8601 date and time the file was uploaded
  var createdDate: Date? { get set }

  /// Custom payload that can be used to store additional file details
  var custom: JSONCodable? { get set }

Failure An Error describing the failure.

Delete file

Description

Delete file from specified Channel.

Method(s)

1. func remove(  fileId: String,  filename: String,  channel: String,  custom requestConfig: RequestConfiguration = RequestConfiguration(),  completion: ((Result<(channel: String, fileId: String), Error>) -> Void)? )
   

   Parameter	Type	Required	Default	Description
   fileId	String	Yes		Unique file identifier which has been assigned during file upload
   filename	String	Yes		Name under which the uploaded file is stored.
   channel	String	Yes		Channel the file was sent to.
   custom	RequestConfiguration	Optional	RequestConfiguration()	Custom configuration overrides when generating the File Upload URLRequest
   completion	((Result<(channel: String, fileId: String), Error>) -> Void)?	Optional		The async Result of the method call.

Basic Usage

self.pubnub.remove(fileId: "id-of-a-file", filename: "example.png", channel: "my_channel") { result in
  case let .success(response):
    print("The file whose ID is \(response.fileId) was removed from \(response.channel)")
  case let .failure(error):
    print("An error occurred while removing the file: \(error.localizedDescription)")
}

Returns

The completion handler will respond with an instance of Result:

Success A Tuple containing the channelthat completed and the fileId of the removed file.

Failure An Error describing the failure.

Publish file message

Description

Publish file message from specified Channel.

Method(s)

1. func publish(  file: PubNubFile,  request: PublishFileRequest,  completion: ((Result<Timetoken, Error>) -> Void)? )
   

   Parameter	Type	Required	Default	Description
   file	PubNubFile	Yes		The PubNubFile representing the uploaded file.
   publishRequest	PublishFileRequest	Optional	PublishFileRequest()	The request configuration object when the file is published to PubNub.
   completion	((Result<(file: PubNubLocalFile, publishedAt: Timetoken), Error>) -> Void)?	Optional		The async Result of the method call.

   PublishFileRequest

   Parameter	Type	Required	Default	Description
   additionalMessage	JSONCodable?	Yes	nil	The optional message to include alongside the File information
   store	Bool?	Optional	nil	If true the published message is stored in history.
   ttl	Int?	Optional	nil	Set a per message time to live in storage.
   meta	JSONCodable?	Optional	nil	Additional metadata to publish alongside the file.
   customRequestConfig	RequestConfiguration	Optional	RequestConfiguration?	Custom configuration overrides for this request.

Basic Usage

let file = PubNubLocalFileBase(
  fileURL: URL(fileURLWithPath: "path/to/example.png"),
  channel: "my_channel",
  fileId: "fileId-from-PubNub"
)

pubnub.publish(
  file: file,
  request: publishRequest
) { result in
  switch result {
  case let .success(timetoken):
    print("File Successfully Published at: \(timetoken)")
  case let .failure(error):
    print("Error publishing file: \(error.localizedDescription)")
  }
}

Returns

The completion handler will respond with an instance of Result:

Success A Timetoken of the published message.

Failure An Error describing the failure.