API Version: v1.2
REST Client Library API

History

The REST client library provides message and presence event history for channels. Channel history combines both instantaneous “live” history as well as the longer term persisted history. If persisted history is enabled for the channel, then messages will typically be stored for 24 – 72 hours on disk. If persisted history is not enabled, Ably retains the last two minutes of instantaneous “live” message history in memory.

Getting started

The Ably REST client library provides a straightforward API to retrieve paginated message or presence event history. Each page of history, by default, contains up to 100 messages. Message ordering, by default, is from most recent to oldest.

var rest = new Ably.Rest('xVLyHw.7bh0WA:B4-4c3dzZOd8lehq');
var channel = rest.channels.get('pad-dug-kid');
channel.publish('example', 'message data', function(err) {
  channel.history(function(err, resultPage) {
    var recentMessage = resultPage.items[0];
    alert('Most recent message: ' + recentMessage.id + ' - ' + recentMessage.data);
  });
});
var rest = new Ably.Rest('xVLyHw.7bh0WA:B4-4c3dzZOd8lehq');
var channel = rest.channels.get('pad-dug-kid');
channel.publish('example', 'message data', function(err) {
  channel.history(function(err, resultPage) {
    var recentMessage = resultPage.items[0];
    console.log('Most recent message: ' + recentMessage.id + ' - ' + recentMessage.data);
  });
});
rest = Ably::Rest.new('xVLyHw.7bh0WA:B4-4c3dzZOd8lehq')
channel = rest.channels.get('pad-dug-kid')
channel.publish 'example', 'message data'
result_page = channel.history
recent_message = result_page.items.first
puts "Most recent message: #{recent_message.message.id} - #{recent_message.data}")
rest = AblyRest('xVLyHw.7bh0WA:B4-4c3dzZOd8lehq')
channel = rest.channels.get('pad-dug-kid')
result_page = channel.history()
recent_message = result_page.items[0]
print('Most recent message: ' + str(recent_message.message.id) + ' - ' + recent_message.data)
$rest = new Ably\AblyRest('xVLyHw.7bh0WA:B4-4c3dzZOd8lehq');
$channel = $rest->channels->get('pad-dug-kid');
$channel->publish('example', 'message data');
$resultPage = $channel->history();
$recentMessage = $resultPage->items[0];
echo("Most recent message data: " . $recentMessage->data);
AblyRest rest = new AblyRest("xVLyHw.7bh0WA:B4-4c3dzZOd8lehq");
Channel channel = rest.channels.get("pad-dug-kid");
channel.publish("example", "message data")
PaginatedResult<Message> resultPage = channel.history(null);
Message recentMessage = resultPage.items[0];
System.out.println("Most recent message: " + recentMessage.id + " - " + recentMessage.data);
AblyRest rest = new AblyRest("xVLyHw.7bh0WA:B4-4c3dzZOd8lehq");
IRestChannel channel = rest.Channels.Get("pad-dug-kid");
await channel.PublishAsync("example", "message data");
PaginatedResult<Message> resultPage = await channel.HistoryAsync();
Message recentMessage = resultPage.Items[0];
Console.WriteLine("Most recent message: " + recentMessage.Id + " - " + recentMessage.Data);
ARTRest *rest = [[ARTRest alloc] initWithKey:@"xVLyHw.7bh0WA:B4-4c3dzZOd8lehq"];
ARTRestChannel *channel = [rest.channels get:@"pad-dug-kid"];
[channel publish:@"example" data:@"message data"];
[channel history:^(ARTPaginatedResult<ARTMessage *> *resultPage, ARTErrorInfo *error) {
    ARTMessage *recentMessage = resultPage.items[0];
    NSLog(@"Most recent message: %@ - %@", recentMessage.id, recentMessage.data);
}];
let rest = ARTRest(key: "xVLyHw.7bh0WA:B4-4c3dzZOd8lehq")
let channel = rest.channels.get("pad-dug-kid")
channel.publish("example", data: "message data")
channel.history { resultPage, error in
    let recentMessage = resultPage!.items[0] as! ARTMessage
    print("Most recent message: \(recentMessage.id) - \(recentMessage.data)")
}
rest, err := ably.NewRestClient(ably.NewClientOptions("xVLyHw.7bh0WA:B4-4c3dzZOd8lehq"))
channel := rest.Channels.Get("pad-dug-kid", nil)
err = channel.Publish("example", "message data")
page, err := channel.History(nil)
fmt.Println("Last published message: %s\n", page.Messages[0].Data)

If you would prefer to just dive into code and see some examples of how to use history via the REST API, then we recommend you take a look at our REST tutorials.

Channel & Presence history

Both the Channel and Presence objects provide history. The Channel object provides the history of Message objects published on the channel, whereas the Presence object provides presence event history of that channel i.e. members entering, updating or leaving the channel as PresenceMessage objects.

Enabling persistent history

By default, persisted history on channels is disabled and messages are only stored by the Ably service for two minutes in memory. If persisted history is enabled for the channel, then messages will typically be stored for 24 – 72 hours on disk.

Every message that is persisted to or retrieved from disk counts as an extra message towards your monthly quote. For example, for a channel that has persistence enabled, if a message is published, two messages will be deducted from your monthly quota. If the message is later retrieved from history, another message will be deducted from your monthly quota.

To enable history on a channel, it is necessary to add a channel rule in the settings of your application dashboard. See the documentation on channel rules for further information on what they are and how to configure them.

API reference

Channel object

The Rest Channel object exposes the following public method to obtain Message history.

Methods

historyHistory

history(Object option, callback(ErrorInfo err, PaginatedResult<Message> resultPage))PaginatedResult<Message> history(Hash option)PaginatedResult<Message> history(kwargs_options)PaginatedResult<Message> history(Array option)PaginatedResult<Message> history(Param[] option)Task<PaginatedResult<Message>> HistoryAsync(PaginatedRequestParams query);history(query: ARTDataQuery?, callback: (ARTPaginatedResult<ARTMessage>?, ARTErrorInfo?) → Void) throws(c *RestChannel) History(option *PaginateParams) (*PaginatedResult, error)

Gets a paginated set of historical messages for this channel.

Parameters

optionqueryParam[] option
an optional object containing the query parametersoptional keyword arguments containing the query parametersan optional set of key value pairs containing the query parametersan Associate Array containing the query parameters, as specified below.
callback
is a function of the form: function(err, resultPage)
callback
called with a ARTPaginatedResult<ARTMessage> object or an error

options parametersARTDataQuery propertiesPaginatedRequestParams properties

start:startStart
beginning of time earliest DateTimeOffset or Time or time in milliseconds since the epoch for any messages retrieved
Type: LongInt or @TimeDateTimeOffset
end:endEnd
current time latest DateTimeOffset or Time or time in milliseconds since the epoch for any messages retrieved
Type: LongInt or @TimeDateTimeOffset
direction:directionDirection
backwards :forwards or :backwards
Type: StringSymbolDirection enum
limit:limitLimit
100 maximum number of messages to retrieve up to 1,000
Type: Integer

Callback result

On success, resultPage contains a PaginatedResult encapsulating an array of Message objects corresponding to the current page of results. PaginatedResult supports pagination using next() and first() methods.

On failure to retrieve message history, err contains an ErrorInfo object with the failure reason.

Returns

On success, the returned PaginatedResult encapsulates an array of Message objects corresponding to the current page of results. PaginatedResult supports pagination using next and first methods.

Failure to retrieve the message history will raise an AblyException

Returns

On success, the returned PaginatedResult encapsulates an array of Message objects corresponding to the current page of results. PaginatedResult supports pagination using next and first methods.

Failure to retrieve the message history will mean error contains an ErrorInfo object with the failure reason.

Returns

This method returns a Task and needs to be awaited.

On success, the returned PaginatedResult encapsulates an array of Message objects corresponding to the current page of results. PaginatedResult supports pagination using NextAsync and FirstAsync methods.

Failure to retrieve the message history will raise an AblyException

Presence object

Rest Presence object exposes the following public method to obtain presence event history such as enter, update and leave events. These events are represented as PresenceMessage objects.

Methods

historyHistory

history(Object option, callback(ErrorInfo err, PaginatedResult<PresenceMessage> resultPage))PaginatedResult<PresenceMessage> history(Hash option)PaginatedResult<PresenceMessage> history(kwargs_options)PaginatedResult<PresenceMessage> history(Array option)PaginatedResult<PresenceMessage> history(Param[] option)Task<PaginatedResult<PresenceMessage>> HistoryAsync(PaginatedRequestParams query);history(query: ARTDataQuery?, callback: (ARTPaginatedResult<ARTPresenceMessage>?, ARTErrorInfo?) → Void) throws(p *RestPresence) History(option *PaginateParams) (*PaginatedResult, error)

Gets a paginated set of historical presence events for this channel.

Parameters

optionParam[] optionPaginatedRequestParams query
an optional object containing the query parametersoptional keyword arguments containing the query parametersan optional set of key value pairs containing the query parametersan Associate Array containing the query parameters, as specified below.
callback
is a function of the form: function(err, resultPage)
callback
called with a ARTPaginatedResult<ARTPresenceMessage> object or an error

options parametersARTDataQuery propertiesPaginatedRequestParams properties

start:startStart
beginning of time earliest DateTimeOffset or Time or time in milliseconds since the epoch for any presence events retrieved
Type: LongInt or @TimeDateTimeOffset
end:endEnd
current time latest DateTimeOffset or Time or time in milliseconds since the epoch for any presence events retrieved
Type: LongInt or @TimeDateTimeOffset
direction:directionDirection
backwards :forwards or :backwards
Type: StringSymbolDirection enum
limit:limitLimit
100 maximum number of presence events to retrieve up to 1,000
Type: Integer

Callback result

On success, resultPage contains a PaginatedResult encapsulating an array of PresenceMessage objects corresponding to the current page of results. PaginatedResult supports pagination using next() and first() methods.

On failure to retrieve presence event history, err contains an ErrorInfo object with the failure reason.

Returns

On success, the returned PaginatedResult encapsulates an array of PresenceMessage objects corresponding to the current page of results. PaginatedResult supports pagination using next and first methods.

Failure to retrieve the presence event history will raise an AblyException

Returns

On success, the returned PaginatedResult encapsulates an array of PresenceMessage objects corresponding to the current page of results. PaginatedResult supports pagination using next and first methods.

Failure to retrieve the message history will mean error contains an ErrorInfo object with the failure reason.

Returns

This method returns a Task and needs to be awaited.

On success, the returned PaginatedResult encapsulates an array of PresenceMessage objects corresponding to the current page of results. PaginatedResult supports pagination using NextAsync and FirstAsync methods.

Failure to retrieve the presence event history will raise an AblyException

MessageARTMessageAbly::Models::Message Enumio.ably.lib.types.MessageIO.Ably.Message

A Message represents an individual message that is sent to or received from Ably.

PropertiesMembersAttributesAttributes

nameName
Event name, if provided
Type: String
dataData
The presence update payload, if provided
Type: String, ByteArray, JSONObject, JSONArrayString, byte[], plain C# object that can be converted to JsonString, []byteString, StringBuffer, JSON ObjectString, Binary (ASCII-8BIT String), Hash, ArrayString, Bytearray, Dict, ListString, NSData, Dictionary, ArrayNSString *, NSData *, NSDictionary *, NSArray *String, Binary String, Associative Array, ArrayObject
extrasExtras
Metadata and/or ancillary payloads, if provided. The only currently valid payload for extras is the push object.
Type: JSONObject, JSONArrayplain C# object that can be converted to JsonString, []byteJSON ObjectHash, ArrayDict, ListDictionary, ArrayNSDictionary *, NSArray *Associative Array, ArrayMap, List
idId
Unique ID assigned by Ably to this message. Can optionally be assigned by the client as part of idempotent publishing
Type: String
clientIdclient_idClientId
The client ID of the publisher of this message
Type: String
connectionIdconnection_idConnectionId
The connection ID of the publisher of this message
Type: String
timestampTimestamp
Timestamp when the message was received by the Ably service, as milliseconds since the epocha Time object
Type: IntegerLong IntegerDateTimeOffsetTimeNSDateDateTime
encodingEncoding
This will typically be empty as all messages received from Ably are automatically decoded client-side using this value. However, if the message encoding cannot be processed, this attribute will contain the remaining transformations not applied to the data payload
Type: String

Message constructors

Message.fromEncoded

Message.fromEncoded(Object encodedMsg, ChannelOptions channelOptions?) → Message

A static factory method to create a Message from a deserialized Message-like object encoded using Ably’s wire protocol.

Parameters

encodedMsg
a Message-like deserialized object.
Type: Object
channelOptions
an optional ChannelOptions. If you have an encrypted channel, use this to allow the library can decrypt the data.
Type: Object

Returns

A Message object

Message.fromEncodedArray

Message.fromEncodedArray(Object[] encodedMsgs, ChannelOptions channelOptions?) → Message[]

A static factory method to create an array of Messages from an array of deserialized Message-like object encoded using Ably’s wire protocol.

Parameters

encodedMsgs
an array of Message-like deserialized objects.
Type: Array
channelOptions
an optional ChannelOptions. If you have an encrypted channel, use this to allow the library can decrypt the data.
Type: Object

Returns

An Array of Message objects

PresenceMessageARTPresenceMessageAbly::Models::PresenceMessage Enumio.ably.lib.types.PresenceMessageIO.Ably.PresenceMessage

A PresenceMessage represents an individual presence update that is sent to or received from Ably.

PropertiesMembersAttributes

action
the event signified by a PresenceMessage. See PresenceMessage.action
Type: enum { ABSENT, PRESENT, ENTER, LEAVE, UPDATE }
Action
the event signified by a PresenceMessage. See PresenceMessage.action
Type: enum { Absent, Present, Enter, Leave, Update }
action
the event signified by a PresenceMessage. See Presence action
Type: int enum { ABSENT, PRESENT, ENTER, LEAVE, UPDATE }
action
the event signified by a PresenceMessage. See PresenceAction
Type: int enum { ABSENT, PRESENT, ENTER, LEAVE, UPDATE }
action
the event signified by a PresenceMessage. See PresenceMessage::ACTION
Type: enum { :absent, :present, :enter, :leave, :update }
action
the event signified by a PresenceMessage. See PresenceMessage::ACTION
Type: const PresenceMessage::ABSENT,PRESENT,ENTER,LEAVE,UPDATE
action
the event signified by a PresenceMessage. See PresenceMessage.action
Type: ARTPresenceAction
Action
the event signified by a PresenceMessage. See PresenceMessage::action
Type: const PresenceMessage::PresenceAbsent,PresencePresent,PresenceEnter,PresenceLeave,PresenceUpdate
dataData
The presence update payload, if provided
String, ByteArray, JSONObject, JSONArrayString, byte[], plain C# object that can be converted to JsonString, StringBuffer, JSON ObjectString, []byteString, Binary (ASCII-8BIT String), Hash, ArrayString, Bytearray, Dict, ListString, NSData, Dictionary, ArrayNSString *, NSData *, NSDictionary *, NSArray *String, Binary String, Associative Array, Array
extrasExtras
Metadata and/or ancillary payloads, if provided. The only currently valid payload for extras is the push object.
Type: JSONObject, JSONArrayplain C# object that can be converted to JsonString, []byteJSON ObjectHash, ArrayDict, ListDictionary, ArrayNSDictionary *, NSArray *Associative Array, Array
idId
Unique ID assigned by Ably to this presence update
Type: String
clientIdclient_idClientId
The client ID of the publisher of this presence update
Type: String
connectionIdconnection_idConnectionId
The connection ID of the publisher of this presence update
Type: String
timestampTimestamp
Timestamp when the presence update was received by Ably, as milliseconds since the epoch.
Type: IntegerLong IntegerDateTimeOffsetTimeNSDate
encodingEncoding
This will typically be empty as all presence updates received from Ably are automatically decoded client-side using this value. However, if the message encoding cannot be processed, this attribute will contain the remaining transformations not applied to the data payload
Type: String

PresenceMessage constructors

PresenceMessage.fromEncoded

PresenceMessage.fromEncoded(Object encodedPresMsg, ChannelOptions channelOptions?) → PresenceMessage

A static factory method to create a PresenceMessage from a deserialized PresenceMessage-like object encoded using Ably’s wire protocol.

Parameters

encodedPresMsg
a PresenceMessage-like deserialized object.
Type: Object
channelOptions
an optional ChannelOptions. If you have an encrypted channel, use this to allow the library can decrypt the data.
Type: Object

Returns

A PresenceMessage object

PresenceMessage.fromEncodedArray

PresenceMessage.fromEncodedArray(Object[] encodedPresMsgs, ChannelOptions channelOptions?) → PresenceMessage[]

A static factory method to create an array of PresenceMessages from an array of deserialized PresenceMessage-like object encoded using Ably’s wire protocol.

Parameters

encodedPresMsgs
an array of PresenceMessage-like deserialized objects.
Type: Array
channelOptions
an optional ChannelOptions. If you have an encrypted channel, use this to allow the library can decrypt the data.
Type: Object

Returns

An Array of PresenceMessage objects

Presence actionPresenceActionARTPresenceActionio.ably.lib.types.PresenceMessage.ActionAbly::Models::PresenceMessage::ACTIONIO.Ably.PresenceAction

Presence action is a String with a value matching any of the Realtime Presence states & events.

var PresenceActions = [
  'absent', // (reserved for internal use)
  'present',
  'enter',
  'leave',
  'update'
]

io.ably.lib.types.PresenceMessage.Action is an enum representing all the Realtime Presence states & events.

public enum Action {
  ABSENT,  // 0 (reserved for internal use)
  PRESENT, // 1
  ENTER,   // 2
  LEAVE,   // 3
  UPDATE   // 4
}

IO.Ably.PresenceAction is an enum representing all the Realtime Presence states & events.

public enum Action {
  Absent,  // 0 (reserved for internal use)
  Present, // 1
  Enter,   // 2
  Leave,   // 3
  Update   // 4
}

PresenceAction is an enum-like class representing all the Realtime Presence states & events.

class PresenceAction(object):
  ABSENT = 0    # (reserved for internal use)
  PRESENT = 1
  ENTER = 2
  LEAVE = 3
  UPDATE = 4

PresenceMessage Action is one of the class constants representing all the Realtime Presence states & events.

namespace Ably\Models;
class PresenceMessages {
  const ABSENT  = 0; /* (reserved for internal use) */
  const PRESENT = 1;
  const ENTER   = 2;
  const LEAVE   = 3;
  const UPDATE  = 4;
}

Example usage

if ($presenceMessage->action == Ably\Models\PresenceMesage::ENTER) {
  /* do something */
}

Ably::Models::PresenceMessage::ACTION is an enum-like value representing all the Realtime Presence states & events. ACTION can be represented interchangeably as either symbols or constants.

Symbol states

:absent  # => 0 (reserved for internal use)
:present # => 1
:enter   # => 2
:leave   # => 3
:update  # => 4

Constant states

PresenceMessage::ACTION.Absent  # => 0 (internal use)
PresenceMessage::ACTION.Present # => 1
PresenceMessage::ACTION.Enter   # => 2
PresenceMessage::ACTION.Leave   # => 3
PresenceMessage::ACTION.Update  # => 4

Example usage

# Example with symbols
presence.on(:attached) { ... }

# Example with constants
presence.on(Ably::Models::PresenceMessage::ACTION.Enter) { ... }

# Interchangeable
Ably::Models::PresenceMessage::ACTION.Enter == :enter # => true

ARTPresenceAction is an enum representing all the Realtime Presence states & events.

typedef NS_ENUM(NSUInteger, ARTPresenceAction) {
    ARTPresenceAbsent,
    ARTPresencePresent,
    ARTPresenceEnter,
    ARTPresenceLeave,
    ARTPresenceUpdate
};
enum ARTPresenceAction : UInt {
  case Absent
  case Present
  case Enter
  case Leave
  case Update
}

Presence action is a String with a value matching any of the Realtime Presence states & events.

const (
  PresenceAbsent = 0
  PresencePresent = 1
  PresenceEnter = 2
  PresenceLeave = 3
  PresenceUpdate = 4
)

IO.Ably.PaginatedRequestParams

HistoryRequestParams is a type that encapsulates the parameters for a history queries. For example usage see Channel#historyChannel#History.

Members

Start
null The start of the queried interval
Type: DateTimeOffset
End
null The end of the queried interval
Type: DateTimeOffset
Limit
null By default it is null. Limits the number of items returned by history or stats
Type: Integer
Direction
Backwards Enum which is either Forwards or Backwards
Type: Direction enum
ExtraParameters
Optionally any extra query parameters that may be passed to the query. This is mainly used internally by the library to manage paging.
Type: Dictionary<string, string>

PaginatedResultARTPaginatedResultAbly::Models::PaginatedResultio.ably.lib.types.PaginatedResultIO.Ably.PaginatedResult

A PaginatedResult is a type that represents a page of results for all message and presence history, stats and REST presence requests. The response from a Ably REST API paginated query is accompanied by metadata that indicates the relative queries available to the PaginatedResult object.

PropertiesMembersAttributes

itemsItems
contains the current page of results (for example an Array of Message or PresenceMessage objects for a channel history request)
Type: Array <Message, Presence, Stats>Type: List <Message, Presence, Stats>

Methods

firstFirst

first(callback(ErrorInfo err, PaginatedResult resultPage))PaginatedResult firstPaginatedResult first()PaginatedResult first()Task<PaginatedResult> FirstAsync()PaginatedResult first()first(callback: (ARTPaginatedResult?, ARTErrorInfo?) → Void)First() (PaginatedResult, error)

Returns a new PaginatedResult for the first page of results. When using the Realtime library, the first method returns a Deferrable and yields a PaginatedResult.The method is asynchronous and returns a Task which needs to be awaited to get the PaginatedResult.

hasNextHasNexthas_next?has_next

Boolean hasNext()Boolean has_next?Boolean hasNext()Boolean has_next()Boolean HasNext()Boolean hasNext()Boolean hasNext()HasNext() (bool)

Returns true if there are more pages available by calling nextNext and returns false if this page is the last page available.

isLastIsLastlast?is_last

Boolean isLast()Boolean last?Boolean isLast()Boolean is_last()Boolean IsLast()Boolean isLast()Boolean isLast()IsLast() (bool)

Returns true if this page is the last page and returns false if there are more pages available by calling nextNext available.

nextNext

next(callback(ErrorInfo err, PaginatedResult resultPage))PaginatedResult nextPaginatedResult next()PaginatedResult next()Task<PaginatedResult> NextAsync()PaginatedResult next()next(callback: (ARTPaginatedResult?, ARTErrorInfo?) → Void)Next() (PaginatedResult, error)

Returns a new PaginatedResult loaded with the next page of results. If there are no further pages, then nulla blank PaginatedResult will be returnedNullNonenil is returned. The method is asynchronous and return a Task which needs to be awaited to get the PaginatedResultWhen using the Realtime library, the first method returns a Deferrable and yields a PaginatedResult.

Example

channel.history(function(err, paginatedResult) {
  console.log('Page 0 item 0:' + paginatedResult.items[0].data);
  paginatedResult.next(function(err, nextPage) {
    console.log('Page 1 item 1: ' + nextPage.items[1].data);
    console.log('Last page?: ' + nextPage.isLast());
  });
});
channel.history(function(err, paginatedResult) {
  console.log('Page 0 item 0:' + paginatedResult.items[0].data);
  paginatedResult.next(function(err, nextPage) {
    console.log('Page 1 item 1: ' + nextPage.items[1].data);
    console.log('Last page?: ' + nextPage.isLast());
  });
});
PaginatedResult firstPage = channel.history();
System.out.println("Page 0 item 0:" + firstPage.items[0].data);
if (firstPage.hasNext) {
  PaginatedResult nextPage = firstPage.next();
  System.out.println("Page 1 item 1:" + nextPage.items[1].data);
  System.out.println("More pages?:" + Strong.valueOf(nextPage.hasNext()));
};
PaginatedResult firstPage = channel.history();
System.out.println("Page 0 item 0:" + firstPage.items[0].data);
if (firstPage.hasNext) {
  PaginatedResult nextPage = firstPage.next();
  System.out.println("Page 1 item 1:" + nextPage.items[1].data);
  System.out.println("More pages?:" + Strong.valueOf(nextPage.hasNext()));
};
PaginatedResult<Message> firstPage = await channel.HistoryAsync(null);
Message firstMessage = firstPage.Items[0];
Console.WriteLine("Page 0 item 0: " + firstMessage.data);
if (firstPage.HasNext)
{
    var nextPage = await firstPage.NextAsync();
    Console.WriteLine("Page 1 item 1:" + nextPage.Items[1].data);
    Console.WriteLine("More pages?: " + nextPage.HasNext());
}
# When using the REST sync library
first_page = channel.history
puts "Page 0 item 0: #{first_page.items[0].data}"
if first_page.has_next?
  next_page = first_page.next
  puts "Page 1 item 1: #{next_page.items[1].data}"
  puts "Last page?: #{next_page.is_last?}"
end

# When using the Realtime EventMachine library
channel.history do |first_page|
  puts "Page 0 item 0: #{first_page.items[0].data}"
  if first_page.has_next?
    first_page.next do |next_page|
      puts "Page 1 item 1: #{next_page.items[1].data}"
      puts "Last page?: #{next_page.is_last?}"
    end
  end
end
result_page = channel.history()
print 'Page 0 item 0: ' + str(result_page.items[0].data)
if result_page.has_next():
  next_page = result_page.next()
  print 'Page 1 item 1: ' + str(next_page.items[1].data)
  print 'Last page?: ' + str(next_page.is_last())
$firstPage = $channel.history();
echo("Page 0 item 0: " . $firstPage->items[0]->data);
if ($firstPage->hasNext()) {
  $nextPage = $firstPage->next();
  echo("Page 1 item 1: " . $nextPage->items[1]->data);
  echo("Last page?: " . $nextPage->isLast());
}
[channel history:^(ARTPaginatedResult<ARTMessage *> *paginatedResult, ARTErrorInfo *error) {
    NSLog(@"Page 0 item 0: %@", paginatedResult.items[0].data);
    [paginatedResult next:^(ARTPaginatedResult<ARTMessage *> *nextPage, ARTErrorInfo *error) {
        NSLog(@"Page 1 item 1: %@", nextPage.items[1].data);
        NSLog(@"Last page?: %d", nextPage.isLast());
    }];
}];
channel.history { paginatedResult, error in
    let paginatedResult = paginatedResult!
    print("Page 0 item 0: \((paginatedResult.items[0] as! ARTMessage).data)")
    paginatedResult.next { nextPage, error in
        let nextPage = nextPage!
        print("Page 1 item 1: \((nextPage.items[1] as! ARTMessage).data)")
        print("Last page? \(nextPage.isLast())")
    }
}
page0, err := channel.History(nil)
fmt.Println("Page. 0 item 0: %s\n", page0.Messages[0].Data)
page1, err := page0.Next()
fmt.Println("Page. 1 item 1: %s\n", page1.Messages[1].Data)
fmt.Println("Last page? %s\n", page1.IsLast())

io.ably.lib.types.Param

Param is a type encapsulating a key/value pair. This type is used frequently in method parameters allowing key/value pairs to be used more flexible, see Channel#history for an example.

Please note that key and value attributes are always strings. If an Integer or other value type is expected, then you must coerce that type into a String.

Members

key
The key value
Type: String
value
The value associated with the key
Type: String

API reference
Documentation