Presence

Methods

get

Get the current presence member set for this channel. In the REST client library this method directly queries Ably's REST presence API

PaginatedResult<PresenceMessage> get(Hash options)

Gets an array of members present on the channel as PresenceMessage objects.

Parameters

options parameters

Returns

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

Failure to retrieve the current presence member set will raise an AblyException

Returns

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

Failure to retrieve the current presence member, the error contains an ErrorInfo object with the failure reason.

history

PaginatedResult<PresenceMessage> history(Hash options)

Gets a paginated set of historical presence message events for this channel. If the channel is configured to persist messages to disk, then the presence message event history will typically be available for 24 - 72 hours. If not, presence message events are only retained in memory by the Ably service for two minutes.

Parameters

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 raise an AblyException

Related types

Ably::Models::PresenceMessage

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

Attributes

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

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

Returns

An Array of PresenceMessage objects

Ably::Models::PresenceMessage::ACTION

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

Ably::Models::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.

Attributes

Methods

first

PaginatedResult first

has_next?

Boolean has_next?

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

last?

Boolean last?

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

next

PaginatedResult next

Returns a new PaginatedResult loaded with the next page of results. If there are no further pages, then is returned. When using the Realtime library, the first method returns a Deferrable and yields a PaginatedResult.

Example

# 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