Message Persistence 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.

The PubNub Message Persistence Service provides real-time access to history for all messages published to PubNub. Each published message is timestamped to the nearest 10 nanoseconds, and is stored across multiple availability zones in several geographical data center locations. Stored messages can be encrypted with AES-256 message encryption, ensuring that they are not readable while stored on PubNub's network.

Messages can be stored for a configurable duration or forever, as controlled by the retention policy that is configured on your account. The following options are available: 1, 3, 5, 7, 15, or 30 days, and Forever.

Fetch History

Requires Message Persistence add-onRequires that the Message Persistence add-on is enabled for your key. See this page on enabling add-on features on your keys:
https://support.pubnub.com/hc/en-us/articles/360051974791-How-do-I-enable-add-on-features-for-my-keys-

Description

This function fetches historical messages from one or multiple channels. The includeMessageActions flag also allows you to fetch message actions along with the messages.

It's possible to control how messages are returned and in what order.

if you specify only the start parameter (without end), you will receive messages that are older than the start timetoken
if you specify only the end parameter (without start), you will receive messages from that end timetoken and newer
if you specify values for both start and end parameters, you will retrieve messages between those timetokens (inclusive of the end value)

You will receive a maximum of 100 messages for a single channel or 25 messages for multiple channels (up to 500). If more messages meet the timetoken criteria, make iterative calls while adjusting the start timetoken to fetch the entire list of messages from storage.

Method(s)

To run Fetch History, you can use the following method(s) in the Swift SDK:

fetchMessageHistory(  for channels: [String],  includeActions actions: Bool = false,  includeMeta: Bool = false,  page: PubNubBoundedPage? = PubNubBoundedPageBase(),  custom requestConfig: RequestConfiguration = RequestConfiguration(),  completion: ((Result<(messagesByChannel: [String: [PubNubMessage]], next: PubNubBoundedPage?), Error>) -> Void)?)

Parameter	Type	Required	Defaults	Description
`for`	[String]	Yes		The list of channels to fetch history messages from. Maximum of 500 channels are allowed.
`includeActions`	Bool	Optional	`false`	If `true` any Message Actions will be included in the response. When set to `true` the method is limited to retrieving history from a single channel.
`includeMeta`	Bool	Optional	`false`	If `true` the meta properties of messages will be included in the response.
`page`	PubNubBoundedPage?	Optional	`PubNubBoundedPageBase()`	The paging object used for pagination. Set `limit` to control the number of results per page. Maximum value is 100 for a single channel, 25 for multiple channels, and 25 when `includeActions` is `true`.
`custom`	RequestConfiguration	Optional	`RequestConfiguration()`	An object that allows for per-request customization of PubNub Configuration or Network Session
`completion`	((Result<(messagesByChannel: [String: [PubNubMessage]], next: PubNubBoundedPage?), Error>) -> Void)?	Optional	`nil`	The async `Result` of the method call

Truncated response

If you fetch messages with messages actions, the number of messages in the response may be truncated when internal limits are hit. If the response is truncated, a more property will be returned with additional parameters. Send iterative calls to history adjusting the parameters to fetch more messages.

Completion Handler Result

Success A Tuple of a Dictionary of channels mapped to an Array their respective PubNubMessages, and the next request PubNubBoundedPage (if one exists).

public protocol PubNubMessage {
  /// The message sent on the channel
  var payload: JSONCodable { get set }

  /// Message actions associated with this message
  var actions: [PubNubMessageAction] { get set }

  /// The channel for which the message belongs
  var channel: String { get }

  /// Timetoken for the message
  var published: Timetoken { get set }

  /// Meta information for the message
  var metadata: JSONCodable? { get set }
}

public protocol PubNubBoundedPage {
  /// The start value for the next set of remote data
  var start: Timetoken? { get }

  /// The bounded end value that will be eventually fetched to
  var end: Timetoken? { get }

  /// The previous limiting value (if any)
  var limit: Int? { get }
}

Failure An Error describing the failure.

Basic Usage

Retrieve the last message on a channel:

pubnub.fetchMessageHistory(for: ["my_channel"]) { result in
  switch result {
  case let .success(response):
    if let myChannelMessages = response.messagesByChannel["my_channel"] {
      print("The list of messages returned for `my_channel`: \(myChannelMessages)")
    }
    if let nextPage = response.next {
      print("The next page used for pagination: \(nextPage)")
    }
  case let .failure(error):
    print("Failed History Fetch Response: \(error.localizedDescription)")
  }
})

Other Examples

Retrieve messages newer than a given timetoken:

pubnub.fetchMessageHistory(
  for: ["my_channel"],
  page: PubNubBoundedPageBase(end: 13406746780720711)
) { result in
  switch result {
  case let .success(response):
    if let myChannelMessages = response.messagesByChannel["my_channel"] {
      print("The list of messages returned for `my_channel`: \(myChannelMessages)")
    }
    if let nextPage = response.next {
      print("The next page used for pagination: \(nextPage)")
    }
  case let .failure(error):
    print("Failed History Fetch Response: \(error.localizedDescription)")
  }
}

Retrieve messages starting from a specific timetoken:

pubnub.fetchMessageHistory(
  for: ["my_channel"],
  page: PubNubBoundedPageBase(start: 13406746780720711)
) { result in
  switch result {
  case let .success(response):
    if let myChannelMessages = response.messagesByChannel["my_channel"] {
      print("The list of messages returned for `my_channel`: \(myChannelMessages)")
    }
    if let nextPage = response.next {
      print("The next page used for pagination: \(nextPage)")
    }
  case let .failure(error):
    print("Failed History Fetch Response: \(error.localizedDescription)")
  }
}

Retrieve the last 10 messages on channelSwift, otherChannel, and myChannel:

pubnub.fetchMessageHistory(
  for: ["channelSwift", "otherChannel", "myChannel"],
  page: PubNubBoundedPageBase(limit: 10)
) { result in
  switch result {
  case let .success(response):
    response.messagesByChannel.forEach { (channel, messages) in
      print("Channel `\(channel)` has the following messages: \(messages)")
    }
    if let nextPage = response.next {
      print("The next page used for pagination: \(nextPage)")
    }
  case let .failure(error):
    print("Failed History Fetch Response: \(error.localizedDescription)")
  }
}

Retrieve messages and their metadata:

pubnub.fetchMessageHistory(
  for: ["my_channel"],
  includeMeta: true
) { result in
  switch result {
  case let .success(response):
    if let myChannelMessages = response.messagesByChannel["my_channel"] {
      print("The list of messages returned for `my_channel`: \(myChannelMessages)")
      myChannelMessages.forEach { message in
        print("The message sent at \(message.published) has the following metadata \(message.metadata)")
      }
    }
    if let nextPage = response.next {
      print("The next page used for pagination: \(nextPage)")
    }
  case let .failure(error):
    print("Failed History Fetch Response: \(error.localizedDescription)")
  }
}

Retrieve messages and their Message Action data:

pubnub.fetchMessageHistory(
  for: ["my_channel"],
  includeActions: true
) { result in
  switch result {
  case let .success(response):
      if let myChannelMessages = response.messagesByChannel["my_channel"] {
        print("The list of messages returned for `my_channel`: \(myChannelMessages)")
        myChannelMessages.forEach { message in
          print("The message sent at \(message.published) has the following actions \(message.actions)")
        }
      }
      if let nextPage = response.next {
        print("The next page used for pagination: \(nextPage)")
      }
  case let .failure(error):
    print("Failed History Fetch Response: \(error.localizedDescription)")
  }
}

Delete Messages from History

Requires Message Persistence add-on Requires that the Message Persistence add-on is enabled for your key. See this page on enabling add-on features on your keys:
https://support.pubnub.com/hc/en-us/articles/360051974791-How-do-I-enable-add-on-features-for-my-keys-

Description

Removes the messages from the history of a specific channel.

Note

There is a setting to accept delete from history requests for a key, which you must enable by checking the Enable Delete-From-History checkbox in the key settings for your key in the Admin Portal.

Requires Initialization with secret key.

Method(s)

To Delete Messages from History you can use the following method(s) in the Swift SDK.

deleteMessageHistory(  from channel: String,  start: Timetoken? = nil,  end: Timetoken? = nil,  custom requestConfig: RequestConfiguration = RequestConfiguration(),  completion: ((Result<Void, Error>) -> Void)?)

Parameter	Type	Required	Defaults	Description
`from`	String	Yes		The channel to delete the messages from.
`start`	Timetoken?	Optional	`nil`	Timetoken delimiting the start of time slice (inclusive) to delete messages from.
`end`	Timetoken?	Optional	`nil`	Timetoken delimiting the end of time slice (exclusive) to delete messages from.
`custom`	RequestConfiguration	Optional	`RequestConfiguration()`	An object that allows for per-request customization of PubNub Configuration or Network Session
`completion`	((Result<Void, Error>) -> Void)?	Optional	`nil`	The async `Result` of the method call

Completion Handler Result

Success A Void indicating a success.
Failure An Error describing the failure.

Basic Usage

pubnub.deleteMessageHistory(
  from: "my_channel"
) { result in
  switch result {
  case let .success:
    print("The message deletion was successful")
  case let .failure(error):
    print("Failed Message Deletion Response: \(error.localizedDescription)")
  }
}

Other Examples

Delete specific message from history

pubnub.deleteMessageHistory(
  from: "my_channel",
  start: 15526611838554310,
  end: 15526611838554309
) { result in
  switch result {
  case let .success:
    print("The message deletion was successful")
  case let .failure(error):
    print("Failed Message Deletion Response: \(error.localizedDescription)")
  }
}

Message Counts

Requires Message Persistence add-on Requires that the Message Persistence add-on is enabled for your key. See this page on enabling add-on features on your keys:
https://support.pubnub.com/hc/en-us/articles/360051974791-How-do-I-enable-add-on-features-for-my-keys-

Description

Returns the number of messages published on one or more channels since a given time. The count returned is the number of messages in history with a timetoken value greater than or equal to than the passed value in the timetokenparameter.

Note

For keys with unlimited message retention enabled, this method considers only messages published in the last 30 days.

Method(s)

You can use the following method(s) in the Swift SDK:

messageCounts(  channels: [String: Timetoken],  custom requestConfig: RequestConfiguration = RequestConfiguration(),  completion: ((Result<[String: Int], Error>) -> Void)?)

Parameter	Type	Required	Defaults	Description
`channels`	[String: Timetoken]	Yes		The map of channels and the `Timetoken` to get the message count for
`custom`	RequestConfiguration	Optional	`RequestConfiguration()`	An object that allows for per-request customization of PubNub Configuration or Network Session
`completion`	((Result<[String: Int], Error>) -> Void)?	Optional	`nil`	The async `Result` of the method call

messageCounts(  channels: [String],  timetoken: Timetoken = 1,  custom requestConfig: RequestConfiguration = RequestConfiguration(),  completion: ((Result<[String: Int], Error>) -> Void)?)

Parameter	Type	Required	Defaults	Description
`channels`	[String]	Yes		The list of channels to get message counts for.
`timetoken`	Timetoken	Optional	`1`	The timetoken for all channels in the list to get message counts for.
`custom`	RequestConfiguration	Optional	`RequestConfiguration()`	An object that allows for per-request customization of PubNub Configuration or Network Session
`completion`	((Result<[String: Int], Error>) -> Void)?	Optional	`nil`	The async `Result` of the method call

Completion Handler Result

Success A Dictionary of channels mapped to their respective message count.
Failure An Error describing the failure.

Basic Usage

pubnub.messageCounts(channels: ["my_channel"]) { result in
  switch result {
  case let .success(messageCountByChannel):
    if let myChannelCount = messageCountByChannel["my_channel"] {
      print("The current message count for `my_channel` is \(myChannelCount)")
    }
  case let .failure(error):
    print("Failed Message Count Response: \(error.localizedDescription)")
  }
}

Other Examples

Retrieve message counts for multiple channels with the same timetoken 15526611838554310:

pubnub.messageCounts(
  channels: ["my_channel", "other_channel", "their_channel"],
  timetoken: 15526611838554310
) { result in
  switch result {
  case let .success(messageCountByChannel):
    messageCountByChannel.forEach { (channel, messageCount) in
      print("The current message count for `\(channel)` is \(messageCount)")
    }
  case let .failure(error):
    print("Failed Message Count Response: \(error.localizedDescription)")
  }
}

Retrieve message counts for multiple channels with different timetokens:

pubnub.messageCounts(
  channels: [
    "my_channel": 15526611838554310,
    "other_channel": 15526611838554309,
    "their_channel": 1
  ]
) { result in
  switch result {
  case let .success(messageCountByChannel):
    messageCountByChannel.forEach { (channel, messageCount) in
      print("The current message count for `\(channel)` is \(messageCount)")
    }
  case let .failure(error):
    print("Failed Message Count Response: \(error.localizedDescription)")
  }
}