File Sharing API for Swift Native SDK

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​

Upload the file to a specified channel.

This method covers the entire process of sending a file, including preparation, uploading the file to a cloud storage service, and post-uploading messaging on a channel.

For the last messaging step, send internally calls the publish method to publish a message on the channel.

The published message contains metadata about the file, such as the file identifier and name, enabling others on the channel to find out about the file and access it.

File encryption

The cryptoModule set in PubNub config will be used for encryption unless you overwrite it using the custom parameter.

For more information, refer to Crypto module configuration.

Method(s)​

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

Details​

/// Content that can be uploaded as a File to PubNub
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)
}

/// Additional information that can be sent during a File publish
struct PublishFileRequest {
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Returns​

The completion handler will respond with a Result.

Success​

A Tuple containing the HTTPFileUploadTask that 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
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Failure​

An Error describing the failure.

Basic Usage​

Reference code

This example is a self-contained code snippet ready to be run. It includes necessary imports and executes methods with console logging. Use it as a reference when working with other examples in this document.


List channel files​

Retrieve list of files uploaded to Channel.

Method(s)​

func listFiles(
    channel: String,
    limit: UInt = 100,
    next: String? = nil,
    custom requestConfig: PubNub.RequestConfiguration = PubNub.RequestConfiguration(),
    completion: ((Result<(files: [PubNubFile], next: String?), Error>) -> Void)?
)
* required
ParameterDescription
channel *
Type: String
Default:
n/a
Channel to get list of files.
limit
Type: UInt
Default:
100
Number of files to return. Minimum value is 1, and maximum is 100.
next
Type: String?
Default:
nil
Random string returned from the server, indicating a specific position in a data set. Used for forward pagination, it fetches the next page, allowing you to continue from where you left off.
custom
Type: PubNub.RequestConfiguration
Default:
PubNub.RequestConfiguration()
Custom configuration overrides when generating the File Upload URLRequest.
completion
Type: ((Result<(files: [PubNubFile], next: String?), Error>) -> Void)?
Default:
n/a
The async Result of the method call.

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
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Failure​

An Error describing the failure.

Basic Usage​


Get File Url​

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

Method(s)​

func generateFileDownloadURL(
    channel: String,
    fileId: String,
    filename: String
) throws -> URL
* required
ParameterDescription
channel *
Type: String
Name of channel to which the file has been uploaded.
fileID *
Type: String
Unique file identifier which has been assigned during file upload.
filename *
Type: String
Name under which the uploaded file is stored.

Returns​

The URL where the file can be downloaded.

Basic Usage​


Download file​

Download file from specified Channel.

File encryption

If the cryptoModule is set in PubNub config, it will be used for decryption.

For more information, refer to Crypto module configuration.

Method(s)​

func download(
    file: PubNubFile,
    toFileURL localFileURL: URL,
    resumeData: Data? = nil,
    downloadTask: @escaping (HTTPFileDownloadTask) -> Void,
    completion: ((Result<(task: HTTPFileDownloadTask, file: PubNubLocalFile), Error>) -> Void)?
)
* required
ParameterDescription
file *
Type: PubNubFile
Default:
n/a
The file that should be downloaded.
toFileURL *
Type: URL
Default:
n/a
The file URL where the file should be downloaded to. This is NOT the URL returned from generateFileDownloadURL.
resumeData
Type: Data?
Default:
nil
A data object that provides the data necessary to resume a download.
downloadTask
Type: (HTTPFileDownloadTask) -> Void
Default:
{ _ in }
The file upload task executing the upload; contains a reference to the actual URLSessionDownloadTask.
completion
Type: ((Result<(task: HTTPFileDownloadTask, file: PubNubLocalFile), Error>) -> Void)?
Default:
n/a
The async Result of the method call.

Returns​

The completion handler will respond with an instance of Result.

Success​

A Tuple containing the HTTPFileDownloadTaskthat 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.

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
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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
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Failure​

An Error describing the failure.

Basic Usage​


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.


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


Delete file​

Delete file from specified Channel.

Method(s)​

func remove(
    fileId: String,
    filename: String,
    channel: String,
    custom requestConfig: PubNub.RequestConfiguration = PubNub.RequestConfiguration(),
    completion: ((Result<(channel: String, fileId: String), Error>) -> Void)?
)
* required
ParameterDescription
fileId *
Type: String
Default:
n/a
Unique file identifier which has been assigned during file upload.
filename *
Type: String
Default:
n/a
Name under which the uploaded file is stored.
channel *
Type: String
Default:
n/a
Channel the file was sent to.
custom
Type: PubNub.RequestConfiguration
Default:
PubNub.RequestConfiguration()
Custom configuration overrides when generating the File Download URLRequest.
completion
Type: ((Result<(channel: String, fileId: String), Error>) -> Void)?
Default:
n/a
The async Result of the method call.

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.

Basic Usage​


Publish file message​

Publish the uploaded file message to a specified channel.

This method is called internally by send as part of the file-sending process to publish the message with the file (already uploaded in a storage service) on a channel.

This message includes the file's unique identifier and name elements, which are needed to construct download links and inform channel subscribers that the file is available for download.

You can call this method when send fails and returns the status.operation === PNPublishFileMessageOperation error. In that case, you can use the data from the status object to try again and use publish to manually resend a file message to a channel without repeating the upload step.

Method(s)​

func publish(
    file: PubNubFile,
    request: PublishFileRequest,
    completion: ((Result<Timetoken, Error>) -> Void)?
)
* required
ParameterDescription
file *
Type: PubNubFile
Default:
n/a
The PubNubFile representing the uploaded file.
request *
Type: PubNub.PublishFileRequest
Default:
n/a
Additional information that can be sent during a File publish.
completion
Type: ((Result<Timetoken, Error>) -> Void)?
Default:
n/a
The async Result of the method call.

PubNub.PublishFileRequest​

* required
ParameterDescription
additionalMessage *
Type: JSONCodable?
Default:
nil
The optional message to include alongside the File information.
customMessageType
Type: String?
Default:
n/a
A case-sensitive, alphanumeric string from 3 to 50 characters describing the business-specific label or category of the message. Dashes - and underscores _ are allowed. The value cannot start with special characters or the string pn_ or pn-.

Examples: text, action, poll.
store
Type: Bool?
Default:
nil
If true the published message is stored in history.
ttl
Type: Int?
Default:
nil
Set a per message time to live in storage.
meta
Type: JSONCodable?
Default:
nil
Additional metadata to publish alongside the file.
customRequestConfig
Type: PubNub.RequestConfiguration
Default:
PubNub.RequestConfiguration?
Custom configuration overrides for this request.

Returns​

The completion handler will respond with an instance of Result.

Success​

A Timetoken of the published message.

Failure​

An Error describing the failure.

Basic Usage​


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