```
public class Presence

                    
```
Enables the presence set to be entered and subscribed to, and the historic presence set to be retrieved for a channel.

Nested Class Summary

Nested Classes
Modifier and Type	Class	Description
`public interface`	`Presence.PresenceListener`	An interface allowing a listener to be notified of arrival of a presence message.

Field Summary

Fields
Modifier and Type	Field	Description
`public final static String`	`GET_WAITFORSYNC`
`public final static String`	`GET_CLIENTID`
`public final static String`	`GET_CONNECTIONID`
`public boolean`	`syncComplete`

Method Summary

Modifier and Type	Method	Description
`synchronized Array<PresenceMessage>`	`get(Array<Param> params)`	Retrieves the current members present on the channel and the metadata for each member,such as their io.ably.lib.types.PresenceMessage.Action and ID.
`synchronized Array<PresenceMessage>`	`get(boolean wait)`	Retrieves the current members present on the channel and the metadata for each member,such as their io.ably.lib.types.PresenceMessage.Action and ID.
`synchronized Array<PresenceMessage>`	`get(String clientId, boolean wait)`	Retrieves the current members present on the channel and the metadata for each member,such as their io.ably.lib.types.PresenceMessage.Action and ID.
`void`	`subscribe(Presence.PresenceListener listener, CompletionListener completionListener)`	Registers a listener that is called each time a PresenceMessage matching a given PresenceMessage.Action,or an action within an array of PresenceMessage.Action, is received on the channel,such as a new member entering the presence set.
`void`	`subscribe(Presence.PresenceListener listener)`	Registers a listener that is called each time a PresenceMessage matching a given PresenceMessage.Action,or an action within an array of PresenceMessage.Action, is received on the channel,such as a new member entering the presence set.
`void`	`unsubscribe(Presence.PresenceListener listener)`	Deregisters a specific listener that is registered to receive PresenceMessage on the channel.
`void`	`subscribe(PresenceMessage.Action action, Presence.PresenceListener listener, CompletionListener completionListener)`	Registers a listener that is called each time a PresenceMessage matching a given PresenceMessage.Action,or an action within an array of PresenceMessage.Action, is received on the channel,such as a new member entering the presence set.
`void`	`subscribe(PresenceMessage.Action action, Presence.PresenceListener listener)`	Registers a listener that is called each time a PresenceMessage matching a given PresenceMessage.Action,or an action within an array of PresenceMessage.Action, is received on the channel,such as a new member entering the presence set.
`void`	`unsubscribe(PresenceMessage.Action action, Presence.PresenceListener listener)`	Deregisters a specific listener that is registered to receive PresenceMessage on the channel for a given PresenceMessage.Action.
`void`	`subscribe(EnumSet<PresenceMessage.Action> actions, Presence.PresenceListener listener, CompletionListener completionListener)`	Registers a listener that is called each time a PresenceMessage matching a given PresenceMessage.Action,or an action within an array of PresenceMessage.Action, is received on the channel,such as a new member entering the presence set.
`void`	`subscribe(EnumSet<PresenceMessage.Action> actions, Presence.PresenceListener listener)`	Registers a listener that is called each time a PresenceMessage matching a given PresenceMessage.Action,or an action within an array of PresenceMessage.Action, is received on the channel,such as a new member entering the presence set.
`void`	`unsubscribe(EnumSet<PresenceMessage.Action> actions, Presence.PresenceListener listener)`	Deregisters a specific listener that is registered to receive PresenceMessage on the channel for a given PresenceMessage.Action.
`void`	`unsubscribe()`	Deregisters all listeners currently receiving PresenceMessage for the channel.
`void`	`enter(Object data, CompletionListener listener)`	Enters the presence set for the channel, optionally passing a data payload.A clientId is required to be present on a channel.An optional callback may be provided to notify of the success or failure of the operation.
`void`	`update(Object data, CompletionListener listener)`	Updates the data payload for a presence member.
`void`	`leave(Object data, CompletionListener listener)`	Leaves the presence set for the channel.A client must have previously entered the presence set before they can leave it.
`void`	`leave(CompletionListener listener)`	Leaves the presence set for the channel.A client must have previously entered the presence set before they can leave it.
`void`	`enterClient(String clientId)`	Enters the presence set of the channel for a given clientId.Enables a single client to update presence on behalf of any number of clients using a single connection.The library must have been instantiated with an API key or a token bound to a wildcard clientId.
`void`	`enterClient(String clientId, Object data)`	Enters the presence set of the channel for a given clientId.Enables a single client to update presence on behalf of any number of clients using a single connection.The library must have been instantiated with an API key or a token bound to a wildcard clientId.
`void`	`enterClient(String clientId, Object data, CompletionListener listener)`	Enters the presence set of the channel for a given clientId.Enables a single client to update presence on behalf of any number of clients using a single connection.The library must have been instantiated with an API key or a token bound to a wildcard clientId.
`void`	`updateClient(String clientId)`	Updates the data payload for a presence member using a given clientId.Enables a single client to update presence on behalf of any number of clients using a single connection.The library must have been instantiated with an API key or a token bound to a wildcard clientId.An optional callback may be provided to notify of the success or failure of the operation.
`void`	`updateClient(String clientId, Object data)`	Updates the data payload for a presence member using a given clientId.Enables a single client to update presence on behalf of any number of clients using a single connection.The library must have been instantiated with an API key or a token bound to a wildcard clientId.An optional callback may be provided to notify of the success or failure of the operation.
`void`	`updateClient(String clientId, Object data, CompletionListener listener)`	Updates the data payload for a presence member using a given clientId.Enables a single client to update presence on behalf of any number of clients using a single connection.The library must have been instantiated with an API key or a token bound to a wildcard clientId.An optional callback may be provided to notify of the success or failure of the operation.
`void`	`leaveClient(String clientId)`	Leaves the presence set of the channel for a given clientId.Enables a single client to update presence on behalf of any number of clients using a single connection.The library must have been instantiated with an API key or a token bound to a wildcard clientId.
`void`	`leaveClient(String clientId, Object data)`	Leaves the presence set of the channel for a given clientId.Enables a single client to update presence on behalf of any number of clients using a single connection.The library must have been instantiated with an API key or a token bound to a wildcard clientId.
`void`	`leaveClient(String clientId, Object data, CompletionListener listener)`	Leaves the presence set of the channel for a given clientId.Enables a single client to update presence on behalf of any number of clients using a single connection.The library must have been instantiated with an API key or a token bound to a wildcard clientId.
`void`	`updatePresence(PresenceMessage msg, CompletionListener listener)`	Update the presence for this channel with a given PresenceMessage update.The connection must be authenticated in a way that enables it to representthe clientId in the message.
`PaginatedResult<PresenceMessage>`	`history(Array<Param> params)`	Retrieves a PaginatedResult object, containing an array of historical PresenceMessage objects for the channel.If the channel is configured to persist messages,then presence messages can be retrieved from history for up to 72 hours in the past.If not, presence messages can only be retrieved from history for up to two minutes in the past.
`void`	`historyAsync(Array<Param> params, Callback<AsyncPaginatedResult<PresenceMessage>> callback)`	Asynchronously retrieves a PaginatedResult object, containing an array of historical PresenceMessage objects for the channel.If the channel is configured to persist messages,then presence messages can be retrieved from history for up to 72 hours in the past.If not, presence messages can only be retrieved from history for up to two minutes in the past.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Method Detail
  - get
```
 synchronized Array<PresenceMessage> get(Array<Param> params)
```
    Retrieves the current members present on the channel and the metadata for each member,such as their io.ably.lib.types.PresenceMessage.Action and ID.Returns an array of PresenceMessage objects.
    Spec: RTP11
    
    Parameters:
    
    params - the request params:waitForSync (RTP11c1) - Sets whether to wait for a full presence set synchronization between Ably and the clients onthe channel to complete before returning the results.
  - get
```
 synchronized Array<PresenceMessage> get(boolean wait)
```
    Retrieves the current members present on the channel and the metadata for each member,such as their io.ably.lib.types.PresenceMessage.Action and ID.Returns an array of PresenceMessage objects.
    Spec: RTP11
    
    Parameters:
    
    wait - (RTP11c1) - Sets whether to wait for a full presence set synchronization between Ably and the clients onthe channel to complete before returning the results.
  - get
```
 synchronized Array<PresenceMessage> get(String clientId, boolean wait)
```
    Retrieves the current members present on the channel and the metadata for each member,such as their io.ably.lib.types.PresenceMessage.Action and ID.Returns an array of PresenceMessage objects.
    Spec: RTP11
    
    Parameters:
    
    clientId - (RTP11c2) - Filters the array of returned presence members by a specific client using its ID.
    
    wait - (RTP11c1) - Sets whether to wait for a full presence set synchronization between Ably and the clients onthe channel to complete before returning the results.
  - subscribe
```
 void subscribe(Presence.PresenceListener listener, CompletionListener completionListener)
```
    Registers a listener that is called each time a PresenceMessage matching a given PresenceMessage.Action,or an action within an array of PresenceMessage.Action, is received on the channel,such as a new member entering the presence set.
    Spec: RTP6a
    
    Parameters:
    
    listener - An event listener function.
    
    completionListener - A callback to be notified of success or failure of the channel attach operation.
  - subscribe
```
 void subscribe(Presence.PresenceListener listener)
```
    Registers a listener that is called each time a PresenceMessage matching a given PresenceMessage.Action,or an action within an array of PresenceMessage.Action, is received on the channel,such as a new member entering the presence set.
    Spec: RTP6a
    
    Parameters:
    
    listener - An event listener function.
  - unsubscribe
```
 void unsubscribe(Presence.PresenceListener listener)
```
    Deregisters a specific listener that is registered to receive PresenceMessage on the channel.
    Spec: RTP7a
    
    Parameters:
    
    listener - An event listener function.
  - subscribe
```
 void subscribe(PresenceMessage.Action action, Presence.PresenceListener listener, CompletionListener completionListener)
```
    Registers a listener that is called each time a PresenceMessage matching a given PresenceMessage.Action,or an action within an array of PresenceMessage.Action, is received on the channel,such as a new member entering the presence set.
    Spec: RTP6b
    
    Parameters:
    
    action - A PresenceMessage.Action to register the listener for.
    
    listener - An event listener function.
    
    completionListener - A callback to be notified of success or failure of the channel attach operation.
  - subscribe
```
 void subscribe(PresenceMessage.Action action, Presence.PresenceListener listener)
```
    Registers a listener that is called each time a PresenceMessage matching a given PresenceMessage.Action,or an action within an array of PresenceMessage.Action, is received on the channel,such as a new member entering the presence set.
    Spec: RTP6b
    
    Parameters:
    
    action - A PresenceMessage.Action to register the listener for.
    
    listener - An event listener function.
  - unsubscribe
```
 void unsubscribe(PresenceMessage.Action action, Presence.PresenceListener listener)
```
    Deregisters a specific listener that is registered to receive PresenceMessage on the channel for a given PresenceMessage.Action.
    Spec: RTP7b
    
    Parameters:
    
    action - A specific PresenceMessage.Action to deregister the listener for.
    
    listener - An event listener function.
  - subscribe
```
 void subscribe(EnumSet<PresenceMessage.Action> actions, Presence.PresenceListener listener, CompletionListener completionListener)
```
    Registers a listener that is called each time a PresenceMessage matching a given PresenceMessage.Action,or an action within an array of PresenceMessage.Action, is received on the channel,such as a new member entering the presence set.
    Spec: RTP6b
    
    Parameters:
    
    actions - An array of PresenceMessage.Action to register the listener for.
    
    listener - An event listener function.
    
    completionListener - A callback to be notified of success or failure of the channel attach operation.
  - subscribe
```
 void subscribe(EnumSet<PresenceMessage.Action> actions, Presence.PresenceListener listener)
```
    Registers a listener that is called each time a PresenceMessage matching a given PresenceMessage.Action,or an action within an array of PresenceMessage.Action, is received on the channel,such as a new member entering the presence set.
    Spec: RTP6b
    
    Parameters:
    
    actions - An array of PresenceMessage.Action to register the listener for.
    
    listener - An event listener function.
  - unsubscribe
```
 void unsubscribe(EnumSet<PresenceMessage.Action> actions, Presence.PresenceListener listener)
```
    Deregisters a specific listener that is registered to receive PresenceMessage on the channel for a given PresenceMessage.Action.
    Spec: RTP7b
    
    Parameters:
    
    actions - An array of specific PresenceMessage.Action to deregister the listener for.
    
    listener - An event listener function.
  - unsubscribe
```
 void unsubscribe()
```
    Deregisters all listeners currently receiving PresenceMessage for the channel.
    Spec: RTP7a, RTE5
  - enter
```
 void enter(Object data, CompletionListener listener)
```
    Enters the presence set for the channel, optionally passing a data payload.A clientId is required to be present on a channel.An optional callback may be provided to notify of the success or failure of the operation.
    Spec: RTP8
    
    Parameters:
    
    data - The payload associated with the presence member.
    
    listener - An callback to notify of the success or failure of the operation.
  - update
```
 void update(Object data, CompletionListener listener)
```
    Updates the data payload for a presence member.If called before entering the presence set, this is treated as an enter event.An optional callback may be provided to notify of the success or failure of the operation.
    Spec: RTP9
    
    Parameters:
    
    data - The payload associated with the presence member.
    
    listener - An callback to notify of the success or failure of the operation.
  - leave
```
 void leave(Object data, CompletionListener listener)
```
    Leaves the presence set for the channel.A client must have previously entered the presence set before they can leave it.
    Spec: RTP10
    
    Parameters:
    
    data - The payload associated with the presence member.
    
    listener - a listener to notify of the success or failure of the operation.
  - leave
```
 void leave(CompletionListener listener)
```
    Leaves the presence set for the channel.A client must have previously entered the presence set before they can leave it.
    Spec: RTP10
    
    Parameters:
    
    listener - a listener to notify of the success or failure of the operation.
  - enterClient
```
 void enterClient(String clientId)
```
    Enters the presence set of the channel for a given clientId.Enables a single client to update presence on behalf of any number of clients using a single connection.The library must have been instantiated with an API key or a token bound to a wildcard clientId.
    Spec: RTP4, RTP14, RTP15
    
    Parameters:
    
    clientId - The ID of the client to enter into the presence set.
  - enterClient
```
 void enterClient(String clientId, Object data)
```
    Enters the presence set of the channel for a given clientId.Enables a single client to update presence on behalf of any number of clients using a single connection.The library must have been instantiated with an API key or a token bound to a wildcard clientId.
    Spec: RTP4, RTP14, RTP15
    
    Parameters:
    
    clientId - The ID of the client to enter into the presence set.
    
    data - The payload associated with the presence member.
  - enterClient
```
 void enterClient(String clientId, Object data, CompletionListener listener)
```
    Enters the presence set of the channel for a given clientId.Enables a single client to update presence on behalf of any number of clients using a single connection.The library must have been instantiated with an API key or a token bound to a wildcard clientId.
    Spec: RTP4, RTP14, RTP15
    
    Parameters:
    
    clientId - The ID of the client to enter into the presence set.
    
    data - The payload associated with the presence member.
    
    listener - An callback to notify of the success or failure of the operation.
  - updateClient
```
 void updateClient(String clientId)
```
    Updates the data payload for a presence member using a given clientId.Enables a single client to update presence on behalf of any number of clients using a single connection.The library must have been instantiated with an API key or a token bound to a wildcard clientId.An optional callback may be provided to notify of the success or failure of the operation.
    Spec: RTP15
    
    Parameters:
    
    clientId - The ID of the client to update in the presence set.
  - updateClient
```
 void updateClient(String clientId, Object data)
```
    Updates the data payload for a presence member using a given clientId.Enables a single client to update presence on behalf of any number of clients using a single connection.The library must have been instantiated with an API key or a token bound to a wildcard clientId.An optional callback may be provided to notify of the success or failure of the operation.
    Spec: RTP15
    
    Parameters:
    
    clientId - The ID of the client to update in the presence set.
    
    data - The payload to update for the presence member.
  - updateClient
```
 void updateClient(String clientId, Object data, CompletionListener listener)
```
    Updates the data payload for a presence member using a given clientId.Enables a single client to update presence on behalf of any number of clients using a single connection.The library must have been instantiated with an API key or a token bound to a wildcard clientId.An optional callback may be provided to notify of the success or failure of the operation.
    Spec: RTP15
    
    Parameters:
    
    clientId - The ID of the client to update in the presence set.
    
    data - The payload to update for the presence member.
    
    listener - An callback to notify of the success or failure of the operation.
  - leaveClient
```
 void leaveClient(String clientId)
```
    Leaves the presence set of the channel for a given clientId.Enables a single client to update presence on behalf of any number of clients using a single connection.The library must have been instantiated with an API key or a token bound to a wildcard clientId.
    Spec: RTP15
    
    Parameters:
    
    clientId - The ID of the client to leave the presence set for.
  - leaveClient
```
 void leaveClient(String clientId, Object data)
```
    Leaves the presence set of the channel for a given clientId.Enables a single client to update presence on behalf of any number of clients using a single connection.The library must have been instantiated with an API key or a token bound to a wildcard clientId.
    Spec: RTP15
    
    Parameters:
    
    clientId - The ID of the client to leave the presence set for.
    
    data - The payload associated with the presence member.
  - leaveClient
```
 void leaveClient(String clientId, Object data, CompletionListener listener)
```
    Leaves the presence set of the channel for a given clientId.Enables a single client to update presence on behalf of any number of clients using a single connection.The library must have been instantiated with an API key or a token bound to a wildcard clientId.
    Spec: RTP15
    
    Parameters:
    
    clientId - The ID of the client to leave the presence set for.
    
    data - The payload associated with the presence member.
    
    listener - An callback to notify of the success or failure of the operation.
  - updatePresence
```
 void updatePresence(PresenceMessage msg, CompletionListener listener)
```
    Update the presence for this channel with a given PresenceMessage update.The connection must be authenticated in a way that enables it to representthe clientId in the message.
    
    Parameters:
    
    msg - the presence message
    
    listener - a listener to be notified on completion of the operation.
  - history
```
 PaginatedResult<PresenceMessage> history(Array<Param> params)
```
    Retrieves a PaginatedResult object, containing an array of historical PresenceMessage objects for the channel.If the channel is configured to persist messages,then presence messages can be retrieved from history for up to 72 hours in the past.If not, presence messages can only be retrieved from history for up to two minutes in the past.
    Spec: RTP12c
    
    Parameters:
    
    params - the request params:start (RTP12a) - The time from which messages are retrieved, specified as milliseconds since the Unix epoch.
  - historyAsync
```
 void historyAsync(Array<Param> params, Callback<AsyncPaginatedResult<PresenceMessage>> callback)
```
    Asynchronously retrieves a PaginatedResult object, containing an array of historical PresenceMessage objects for the channel.If the channel is configured to persist messages,then presence messages can be retrieved from history for up to 72 hours in the past.If not, presence messages can only be retrieved from history for up to two minutes in the past.
    Spec: RTP12c
    
    Parameters:
    
    params - the request params:start (RTP12a) - The time from which messages are retrieved, specified as milliseconds since the Unix epoch.
    
    callback - A Callback returning AsyncPaginatedResult object containing an array of PresenceMessage objects.

Class Presence

Nested Class Summary

Field Summary

Method Summary

Methods inherited from class java.lang.Object

Method Detail

get

get

get

subscribe

subscribe

unsubscribe

subscribe

subscribe

unsubscribe

subscribe

subscribe

unsubscribe

unsubscribe

enter

update

leave

leave

enterClient

enterClient

enterClient

updateClient

updateClient

updateClient

leaveClient

leaveClient

leaveClient

updatePresence

history

historyAsync