Message Persistence API for PubNub Ruby SDK

Message Persistence provides real-time access to the history of 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 locations. Stored messages can be encrypted with AES-256 message encryption, ensuring that they are not readable while stored on PubNub's network. For more information, refer to Message Persistence.

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 day, 7 days, 30 days, 3 months, 6 months, 1 year, or Unlimited.

You can retrieve the following:

• Messages
• Message actions
• File Sharing (using File Sharing API)

History

Requires Message Persistence

This method requires that Message Persistence is enabled for your key in the Admin Portal. Read the support page on enabling add-on features on your keys.

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 start OR end timetoken.
• Retrieve a slice of the time line by providing both a start AND end timetoken.
• Limit the number of messages to a specific quantity using the count parameter.

Start & End parameter usage clarity

If only the start parameter is specified (without end), you will receive messages that are older than and up to that start timetoken value. If only the end parameter is specified (without start) you will receive messages that match that end timetoken value and newer. Specifying values for both start and end parameters will return messages between those timetoken values (inclusive on the end 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 start 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 Ruby SDK:

history(
    channels: channels,
    count: count,
    start: start,
    end: end,
    reverse: reverse,
    include_token: include_token,
    http_sync: http_sync,
    callback: callback
)

Parameter	Type	Required	Description
channels	String, Symbol	Yes	Specify channels to return history messages from.
count	Integer	Optional	Specifies the number of historical messages to return. Default/maximum is 100.
start	Integer	Optional	Timetoken delimiting the start of time slice (exclusive) to pull messages from.
end	Integer	Optional	Timetoken delimiting the end of time slice (inclusive) to pull messages from.
reverse	Boolean	Optional	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.
http_sync	Boolean	Optional	Default false. Method will be executed asynchronously and will return future, to get its value you can use value method. If set to true, method will return array of envelopes (even if there's only one envelope). For sync methods Envelope object will be returned.
include_token	Boolean	Optional	With include_token parameter set to true each envelope will contain timetoken specific for message that it holds. Default: false
callback	Lambda accepting one parameter	Optional	Callback that will be called for each envelope. For async methods future will be returned, to retrieve value Envelope object you have to call value method (thread will be locked until the value is returned).

tip

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 count, 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:

pubnub.history(
    channel: 'history_channel',
    count: 100
) do |envelope|
    puts envelope.result[:data][:messages]
end

Response

The Ruby SDK returns false on fail. An array is returned on success.

The history() function returns a list of up to 100 messages, the timetoken of the first (oldest) message and the timetoken of the last (newest) message in the resulting set of messages. The output below demonstrates the format for a history() response:

#<Pubnub::Envelope:0x007fd384da4ad0
    @result = {
        :data => {
            :messages => ["Pub1", "Pub2", "Pub3", "Pub4", "Pub5", "Pub6", "Pub7", "Pub8", "Pub9", "Pub10"],
            :end => 15010808292416521,
            :start => 15010808287349573
        }
    },
    @status = {
        :code => 200
    }
>

Other Examples

Use history() to retrieve the three oldest messages by retrieving from the time line in reverse

pubnub.history(
    channel: :history,
    count: 3,
    reverse: true,
    http_sync: true
)

Response

#<Pubnub::Envelope:0x007fd3858e34c8
    @result = {
        :data => {
            :messages => ["Pub1", "Pub2", "Pub3"],
            :end => 15010808288498250,
            :start => 15010808287349573
        }
    },
    @status = {
        :code => 200
    }
>

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

pubnub.history(
    channel: :history,
    start: 15010808287700000,
    reverse: true,
    http_sync: true
)

Response

#<Pubnub::Envelope:0x007fd38523ced0
    @result = {
        :data => {
            :messages => ["Pub1"],
            :end => 15010808287349573,
            :start => 15010808287349573
        }
    }
    @status = {
        :code => 200
    }
>

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

pubnub.history(
    channel: :history,
    end: 15010808287700000,
    http_sync: true
)

Response

#<Pubnub::Envelope:0x007fd3860dbce8
    @result = {
        :data => {
            :messages => ["Pub2", "Pub3", "Pub4", "Pub5", "Pub6", "Pub7", "Pub8", "Pub9", "Pub10"],
            :end => 15010808292416521,
            :start => 15010808287951883
        }
    }
    @status = {
        :code => 200
    }
>

History Paging Example

Usage

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

pubnub.paged_history(channel: :messages, limit: 10, page: 20) do |envelope|
    puts envelope.result[:data][:messages]
end

Include timetoken in history response

# ASYNC
# Call history with include_token: true
future_envelope = pubnub.history(channel: :demo, include_token: true)
# Get timetoken of first retrieved message
future_envelope.value.result[:data][:messages].first['timetoken']

# SYNC
# Call history with include_token: true
envelope = pubnub.history(channel: :demo, include_token: true, http_sync: true)
# Get timetoken of first retrieved message
envelope.result[:data][:messages].first['timetoken']

# Example response in result[:data][:messages]
# [
#   {"message"=>"Whatever", "timetoken"=>14865606002747651},

show all 18 lines

Delete Messages from History

Requires Message Persistence

This method requires that Message Persistence is enabled for your key in the Admin Portal. Read the support page on enabling add-on features on your keys.

Removes the messages from the history of a specific channel.

Required setting

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 Ruby SDK.

delete_messages(
    channels: channels,
    start: start,
    end: end,
    http_sync: http_sync,
    callback: callback
)

Parameter	Type	Required	Description
channels	String, Symbol	Yes	Channels from which messages will be deleted.
start	String, Integer	No	Timestamp since when messages should be deleted.
end	String, Integer	No	Timestamp until when messages should be deleted.
http_sync	Boolean	No	Default false. Method will be executed asynchronously and will return future, to get its value you can use value method. If set to true, method will return array of envelopes (even if there's only one envelope). For sync methods Envelope object will be returned.
callback	Lambda accepting one parameter	No	Callback that will be called for each envelope. For async methods future will be returned, to retrieve value Envelope object you have to call value method (thread will be locked until the value is returned).

Basic Usage

pubnub.delete_messages(channel: 'my-channel', start: 1508284800, end: 1508935781, callback: check_response_status)

Response

#<Pubnub::Envelope
    @status = {
        :code => 200,
        :operation => :delete,
        :category => :ack,
        :error => false,
        # [...]
    },
    # [...]
>

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. For example, if 15526611838554310 is the publish timetoken, pass 15526611838554309 in start and 15526611838554310 in end parameters respectively as shown in the following code snippet.

pubnub.delete_messages(channel: 'my-channel', start: 15526611838554310, end: 15526611838554309, callback: check_response_status)

Message Counts

Requires Message Persistence

This method requires that Message Persistence is enabled for your key in the Admin Portal. Read the support page on enabling add-on features on your keys.

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 channel_timetokensparameter.

Unlimited message retention

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 Ruby SDK:

pubnub.message_counts(
    channels: array_of_channels,
    channel_timetokens: array_of_timetokens
)

Parameter	Type	Required	Default	Description
channel	String, Symbol	Yes		Either array of channels, string with single channel or string with comma separated channels
channel_timetokens	Array	Yes	null	Array of timetokens, in order of the channels list. Specify a single timetoken to apply it to all channels. Otherwise, the list of timetokens must be the same length as the list of channels, or the function returns a PNStatus with an error flag.
http_sync	Boolean	No		Default false. Method will be executed asynchronously and will return future, to get its value you can use value method. If set to true, method will return array of envelopes (even if there's only one envelope). For sync methods Envelope object will be returned.

Basic Usage

envelope = pubnub.message_counts(channel:['a', 'b', 'c', 'd'], channel_timetokens: 12123).value
    p envelope.result[:data]

Returns

Channels count

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

Returns Concurrent::Future object if PubNub is configured with http_sync: false (default behavior) or envelope if it's set to sync mode

#<Pubnub::Envelope
    @result=
      {
       :data=>
        {
         "channels"=>{"a"=>2, "c"=>0, "b"=>0, "d"=>0}
        }
     @status=
      {
        :code=>200
      }
>

Other Examples

Retrieve count of messages using different timetokens for each channel

envelope = pubnub.message_counts(channel:['a', 'b', 'c', 'd'], channel_timetokens: [123135129, 123135124, 12312312, 123135125]).value
    p envelope.result[:data]