Message Persistence API for PubNub Cocoa Swift SDK

This SDK has been replaced by a new PubNub Swift SDK written purely in Swift. Check it out here

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.

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

This function fetches historical messages of a channel.

It is possible to control how messages are returned and in what order, for example you can:

Search for messages starting on the newest end of the timeline (default behavior - reverse = false)
Search for messages from the oldest end of the timeline by setting reverse to true.
Page through results by providing a startDate OR endDate timetoken.
Retrieve a slice of the time line by providing both a startDate AND endDate timetoken.
Limit the number of messages to a specific quantity using the limit parameter.

Start & End parameter usage clarity:

If only the startDate parameter is specified (without endDate), you will receive messages that are older than and up to that startDate timetoken value. If only the endDate parameter is specified (without startDate) you will receive messages that match that endDate timetoken value and newer Specifying values for both startDate and endDate parameters will return messages between those timetoken values (inclusive on the endDate value). Keep in mind that you will still receive a maximum of 100 messages even if there are more messages that meet the timetoken values. Iterative calls to history adjusting the startDate timetoken is necessary to page through the full set of results if more than 100 messages meet the timetoken values.

Method(s)

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

open func historyForChannel(_ channel: String, withCompletion closure: PubNub.PNHistoryCompletionBlock)

Parameter	Type	Required	Description
`channel`	String	Yes	`Channel` name to retrieve the History information.
`closure`	PNHistoryCompletionBlock	Yes	The completion `closure` has two arguments: result - in case of successful processing (data field will contain results of history request operation);status - in case if error occurred during request processing (errorData contains error information).

open func historyForChannel(_ channel: String, start startDate: NSNumber?, end endDate: NSNumber?, withCompletion closure: PubNub.PNHistoryCompletionBlock)

Parameter	Type	Required	Description
`channel`	String	Yes	`Channel` name to retrieve the History information.
`startDate`	NSNumber	No	Timetoken delimiting the start of time slice (exclusive) to pull messages from.
`endDate`	NSNumber	No	Timetoken delimiting the end of time slice (inclusive) to pull messages from.
`closure`	PNHistoryCompletionBlock	Yes	The completion `closure` has two arguments: result - in case of successful processing (data field will contain results of history request operation);status - in case if error occurred during request processing (errorData contains error information).

open func historyForChannel(_ channel: String, start startDate: NSNumber?, end endDate: NSNumber?, limit: UInt, withCompletion closure: PubNub.PNHistoryCompletionBlock)

Parameter	Type	Required	Description
`channel`	String	Yes	`Channel` name to retrieve the History information.
`startDate`	NSNumber	No	Timetoken delimiting the start of time slice (exclusive) to pull messages from.
`endDate`	NSNumber	No	Timetoken delimiting the end of time slice (inclusive) to pull messages from.
`limit`	UInt	Yes	Specifies the number of historical messages to return. default/maximum is 100.
`closure`	PNHistoryCompletionBlock	Yes	The completion `closure` has two arguments: result - in case of successful processing (data field will contain results of history request operation);status - in case if error occurred during request processing (errorData contains error information).

open func historyForChannel(_ channel: String, start startDate: NSNumber?, end endDate: NSNumber?, includeTimeToken shouldIncludeTimeToken: Bool, withCompletion closure: PubNub.PNHistoryCompletionBlock)

Parameter	Type	Required	Description
`channel`	String	Yes	`Channel` name to retrieve the History information.
`startDate`	NSNumber	No	Timetoken delimiting the start of time slice (exclusive) to pull messages from.
`endDate`	NSNumber	No	Timetoken delimiting the end of time slice (inclusive) to pull messages from.
`shouldIncludeTimeToken`	Bool	Yes	If true the `message` post timestamps will be included in the history response.
`closure`	PNHistoryCompletionBlock	Yes	The completion `closure` has two arguments: result - in case of successful processing (data field will contain results of history request operation); status - in case if error occurred during request processing (errorData contains error information).

open func historyForChannel(_ channel: String, start startDate: NSNumber?, end endDate: NSNumber?, limit: UInt, includeTimeToken shouldIncludeTimeToken: Bool, withCompletion closure: PubNub.PNHistoryCompletionBlock)

Parameter	Type	Required	Description
`channel`	String	Yes	`Channel` name to retrieve the History information.
`startDate`	NSNumber	No	Timetoken delimiting the start of time slice (exclusive) to pull messages from.
`endDate`	NSNumber	No	Timetoken delimiting the end of time slice (inclusive) to pull messages from.
`limit`	UInt	Yes	Specifies the number of historical messages to return. default/maximum is 100.
`shouldIncludeTimeToken`	Bool	Yes	If `true` the `message` post timestamps will be included in the history response.
`closure`	PNHistoryCompletionBlock	Yes	The completion `closure` has two arguments: result - in case of successful processing (data field will contain results of history request operation); status - in case if error occurred during request processing (errorData contains error information).

open func historyForChannel(_ channel: String, start startDate: NSNumber?, end endDate: NSNumber?, limit: UInt, reverse shouldReverseOrder: Bool, withCompletion closure: PubNub.PNHistoryCompletionBlock)

Parameter	Type	Required	Description
`channel`	String	Yes	`Channel` name to retrieve the History information.
`startDate`	NSNumber	No	Timetoken delimiting the start of time slice (exclusive) to pull messages from.
`endDate`	NSNumber	No	Timetoken delimiting the end of time slice (inclusive) to pull messages from.
`limit`	UInt	Yes	Specifies the number of historical messages to return. Default/maximum is 100.
`shouldReverseOrder`	Bool	Yes	Setting to `true` will traverse the time line in reverse starting with the oldest `message` first. Default is false. If both `start` and `end` arguments are provided, reverse is ignored and messages are returned starting with the newest `message`.
`closure`	PNHistoryCompletionBlock	Yes	The completion `closure` has two arguments: result - in case of successful processing (data field will contain results of history request operation); status - in case if error occurred during request processing (errorData contains error information).

open func historyForChannel(_ channel: String, start startDate: NSNumber?, end endDate: NSNumber?, limit: UInt, reverse shouldReverseOrder: Bool, includeTimeToken shouldIncludeTimeToken: Bool, withCompletion closure: PubNub.PNHistoryCompletionBlock)

Parameter	Type	Required	Description
`channel`	String	Yes	`Channel` name to retrieve the History information.
`startDate`	NSNumber	No	`Timetoken` delimiting the start of time slice (exclusive) to pull messages from.
`endDate`	NSNumber	No	`Timetoken` delimiting the end of time slice (inclusive) to pull messages from.
`limit`	UInt	Yes	Specifies the number of historical messages to return. default/maximum is 100.
`shouldReverseOrder`	Bool	Yes	Setting to `true` will traverse the time line in reverse starting with the oldest `message` first. Default is `false`. If both start and end arguments are provided, reverse is ignored and messages are returned starting with the newest `message`.
`shouldIncludeTimeToken`	Bool	Yes	If true the `message` post timestamps will be included in the history response.
`closure`	PNHistoryCompletionBlock	Yes	The completion `closure` has two arguments: result - in case of successful processing (data field will contain results of history request operation);status - in case if error occurred during request processing (errorData contains error information).

Using the `reverse` parameter:

Messages are always returned sorted in ascending time direction from history regardless of reverse. The reverse direction matters when you have more than 100 (or limit, if it's set) messages in the time interval, in which case reverse determines the end of the time interval from which it should start retrieving the messages.

Basic Usage

Retrieve the last 100 messages on a channel:

self.client.historyForChannel("history_channel", withCompletion: { (result, status) in

    if status == nil {

        /**
         Handle downloaded history using:
            result.data.start - oldest message time stamp in response
            result.data.end - newest message time stamp in response
            result.data.messages - list of messages
         */
    }
    else {

        /**
         Handle message history download error. Check 'category' property
         to find out possible reason because of which request did fail.
         Review 'errorData' property (which has PNErrorData data type) of status
         object to get additional information about issue.

         Request can be resent using: status.retry()
         */
    }
})

Response

The response object which is returned by the client when the history API is used:

open class PNHistoryData : PNServiceData {

    // Channel history messages.
    open var messages: [Any] { get }
    // History time frame start time.
    open var start: NSNumber { get }
    // History time frame end time.
    open var end: NSNumber { get }
}

open class PNHistoryResult : PNResult {

    // Stores reference on channel history request processing information.
    open var data: PNHistoryData { get }
}

Other Examples

Use historyForChannel to retrieve the three oldest messages by retrieving from the time line in reverse:

self.client.historyForChannel("my_channel", start: nil, end: nil, limit: 3,
                              reverse: true, withCompletion: { (result, status) in

    if status == nil {

        /**
         Handle downloaded history using:
            result.data.start - oldest message time stamp in response
            result.data.end - newest message time stamp in response
            result.data.messages - list of messages
         */
    }
    else {

        /**
         Handle message history download error. Check 'category' property
         to find out possible reason because of which request did fail.
         Review 'errorData' property (which has PNErrorData data type) of status
         object to get additional information about issue.

         Request can be resent using: status.retry()
         */
    }
})

Response:

[
    ["Pub1","Pub2","Pub3"],
    13406746729185766,
    13406746780720711
]

Use historyForChannel to retrieve messages newer than a given timetoken by paging from oldest message to newest message starting at a single point in time (exclusive):

let start = NSNumber(value: (13406746780720711 as CUnsignedLongLong))
self.client.historyForChannel("my_channel", start: start, end: nil, limit: 100,
                              reverse: true, withCompletion: { (result, status) in

    if status == nil {

        /**
         Handle downloaded history using:
            result.data.start - oldest message time stamp in response
            result.data.end - newest message time stamp in response
            result.data.messages - list of messages
         */
    }
    else {

        /**
         Handle message history download error. Check 'category' property
         to find out possible reason because of which request did fail.
         Review 'errorData' property (which has PNErrorData data type) of status
         object to get additional information about issue.

         Request can be resent using: status.retry()
         */
    }
})

Response

[
    ["Pub3","Pub4","Pub5"],
    13406746780720711,
    13406746845892666
]

Use historyForChannel to retrieve messages until a given timetoken by paging from newest message to oldest message until a specific end point in time (inclusive):

let end = NSNumber(value: (13406746780720711 as CUnsignedLongLong))
self.client.historyForChannel("my_channel", start: nil, end: end, limit: 100, reverse: true,
                              withCompletion: { (result, status) in

    if status == nil {

        /**
         Handle downloaded history using:
            result.data.start - oldest message time stamp in response
            result.data.end - newest message time stamp in response
            result.data.messages - list of messages
         */
    }
    else {

        /**
         Handle message history download error. Check 'category' property
         to find out possible reason because of which request did fail.
         Review 'errorData' property (which has PNErrorData data type) of status
         object to get additional information about issue.

         Request can be resent using: status.retry()
         */
    }
})

Response:

[
    ["Pub3","Pub4","Pub5"],
    13406746780720711,
    13406746845892666
]

History Paging Example

Usage!

You can call the method by passing 0 or a valid timetoken as the argument.

// Pull out all messages newer than message sent at 14395051270438477.
let date = NSNumber(value: (14395051270438477 as CUnsignedLongLong));
self.historyNewerThan(date, onChannel: "history_channel", withCompletion:  { (messages) in

    print("Messages from history: \(messages)")
})

func historyNewerThan(_ date: NSNumber, onChannel channel: String,
                      withCompletion closure: @escaping (Array<Any>) -> Void) {

    var msgs: Array<Any> = []
    self.historyNewerThan(date, onChannel: channel, withProgress: { (messages) in

        msgs.append(contentsOf: messages)
        if messages.count < 100 { closure(msgs) }
    })
}

private func historyNewerThan(_ date: NSNumber, onChannel channel: String,
                              withProgress closure: @escaping (Array<Any>) -> Void) {

    self.client?.historyForChannel(channel, start: date, end: nil, limit: 100,
                                   reverse: false, withCompletion: { (result, status) in

        if status == nil {

            closure((result?.data.messages)!)
            if result?.data.messages.count == 100 {

                self.historyNewerThan((result?.data.start)!, onChannel: channel,
                                      withProgress: closure)
            }
        }
        else {

            /**
             Handle message history download error. Check the 'category' property
             to find out why the request failed.
             Review the 'errorData' property (of type PNErrorData) of the status
             object to get additional information about the issue.

             Request can be resent using: [status retry];
            */
        }
    })
}

History (Builder Pattern)

Description

This function fetches historical messages of a channel.

This method uses the builder pattern; you can omit any optional arguments.

Method(s)

To get channel history using the Builder pattern, use the following method(s) in the Swift SDK:

history().channels([String]).limit(UInt).performWithCompletion(PubNub.PNHistoryCompletionBlock);

Parameter	Type	Required	Description
`channels`	[String]	Yes	List of `channels` for which history should be returned.
`limit`	UInt	No	Maximum number of messages which should be returned for each channel. Default and maximum value is 100 for a single channel, 25 for multiple channels.
`completion`	PNHistoryCompletionBlock	Yes	History pull processing completion block which pass two arguments: result - in case of successful request processing data field will contain results of history request operation; status - in case if error occurred during request processing.

Using the `reverse` parameter:

Basic Usage

self.client.history().channels(["my_channel"]).limit(15).performWithCompletion({ (result, status) in

    if status == nil {

        /**
         Handle downloaded history using:
         result.data.channels - dictionary with channels' history. Each key is channel name and value is
         list of fetched messages.
         */
    }
    else {

        /**
         Handle message history download error. Check 'category' property
         to find out possible reason because of which request did fail.
         Review 'errorData' property (which has PNErrorData data type) of status
         object to get additional information about issue.

         Request can be resent using: [status retry]
         */
    }
})

Delete Messages from History

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.

open func deleteMessagesFromChannel(_ channel: String, start startDate: NSNumber?, end endDate: NSNumber?, withCompletion closure: PubNub.PNMessageDeleteCompletionBlock? = nil)

Basic Usage

let startDate = NSNumber(value: (15101397027611671 as CUnsignedLongLong))
let endDate = NSNumber(value: (15101397427611671 as CUnsignedLongLong))
self.client.deleteMessagesFromChannel("channel", start: startDate, end: endDate, withCompletion: { (status) in

    if !status.isError {
        // Messages within specified time frame has been removed.
    } else {
       /**
        * Handle message history download error. Check 'category' property to find out possible
        * issue because of which request did fail.
        *
        * Request can be resent using: status.retry()
        */
    }
})

Other Examples

Delete specific message from history

To delete a specific message, pass the publish timetoken (received from a successful publish) in the End parameter and timetoken +/- 1 in the Start parameter. e.g. if 15526611838554310 is the publish timetoken, pass 15526611838554309 in Start and 15526611838554310 in End parameters respectively as shown in the following code snippet.

let startDate = NSNumber(value: (15526611838554310 as CUnsignedLongLong))
let endDate = NSNumber(value: (15526611838554309 as CUnsignedLongLong))
self.client.deleteMessagesFromChannel("channel", start: startDate, end: endDate, withCompletion: { (status) in

    if !status.isError {
        // Messages within specified time frame has been removed.
    } else {
       /**
        * Handle message history download error. Check 'category' property to find out possible
        * issue because of which request did fail.
        *
        * Request can be resent using: status.retry()
        */
    }
})

Delete Messages from History (Builder Pattern)

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.

deleteMessage().channel(String).start(NSNumber?).end(NSNumber?).performWithCompletion(PubNub.PNMessageDeleteCompletionBlock? = nil)

Basic Usage

let startDate = NSNumber(value: (15101397027611671 as CUnsignedLongLong))
let endDate = NSNumber(value: (15101397427611671 as CUnsignedLongLong))
self.client.deleteMessage().channel("channel").start(startDate).end(endDate).performWithCompletion({ (status) in

    if !status.isError {
        // Messages within specified time frame has been removed.
    } else {
       /**
        * Handle message history download error. Check 'category' property to find out possible
        * issue because of which request did fail.
        *
        * Request can be resent using: status.retry()
        */
    }
})

Message Counts

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 timetokensparameter.

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]).timetokens([Int]).performWithCompletion(PNMessageCountCompletionBlock)

Parameter	Type	Required	Description
`channels`	[String]	Yes	The `channels` to fetch the message count
`timetokens`	[Int]	Yes	List with single or multiple timetokens, where each timetoken position in correspond to target `channel` location in channel names list.
`completion`	PNMessageCountCompletionBlock	Yes	Messages count fetch completion closure which pass two arguments: `result` - in case of successful request processing data field will contain results of message count fetch operation; `status` - in case of error occurred during request processing.

Basic Usage

let timetoken = NSNumber(value: (15501015683744028 as CUnsignedLongLong))
self.client.messageCounts().channels(["unread-channel-1", "unread-channel-2"])
    .timetokens([timetoken])
    .performWithCompletion({ (result, status) in

        if !status.isError {
            // Client state retrieved number of messages for channels.
        } else {
            /**
             Handle client state modification error. Check 'category' property
             to find out possible reason because of which request did fail.
             Review 'errorData' property (which has PNErrorData data type) of status
             object to get additional information about issue.

             Request can be resent using: status.retry()
            */
        }
    });

Returns

Note

Channels without messages have a count of 0. Channels with 10,000 messages or more have a count of 10000.

open class PNMessageCountData : PNServiceData {

    // Dictionary where each key is name of channel and value is number of messages in it.
    var channels: [String:Int] { get }
}

open class PNMessageCountResult : PNResult {

    // Message count request processing information.
    var data: PNMessageCountData { get }
}

Other Examples

Retrieve count of messages using different timetokens for each channel

let timetoken = NSNumber(value: (15501015683744028 as CUnsignedLongLong))
let timetoken2 = NSNumber(value: (15501015683744130 as CUnsignedLongLong))
self.client.messageCounts().channels(["unread-channel-1", "unread-channel-2"])
    .timetokens([timetoken, timetoken2])
    .performWithCompletion({ (result, status) in

        if !status.isError {
            // Client state retrieved number of messages for channels.
        } else {
            /**
             Handle client state modification error. Check 'category' property
             to find out possible reason because of which request did fail.
             Review 'errorData' property (which has PNErrorData data type) of status
             object to get additional information about issue.

             Request can be resent using: status.retry()
            */
        }
    });

History

Description

Start & End parameter usage clarity:

Method(s)

Using the reverse parameter:

Basic Usage

Response

Other Examples

Usage!

History (Builder Pattern)

Description

Method(s)

Using the reverse parameter:

Basic Usage

Delete Messages from History

Description

Note

Method(s)

Basic Usage

Other Examples

Delete Messages from History (Builder Pattern)

Description

Note

Method(s)

Basic Usage

Message Counts

Description

Note

Method(s)

Basic Usage

Returns

Note

Other Examples

Using the `reverse` parameter:

Using the `reverse` parameter: