Presence API for Swift Native SDK

Presence enables you to track the online and offline status of users and devices in real time, and store custom state information. Presence provides authoritative information on:

  • When a user has joined or left a channel
  • Who, and how many, users are subscribed to a particular channel
  • Which channel(s) an individual user is subscribed to
  • Associated state information for these users

Learn more about our Presence feature here.

Here Now​

Requires Presence

This method requires that the Presence add-on is enabled for your key in the Admin Portal.

You can obtain information about the current state of a channel including a list of unique user-ids currently subscribed to the channel and the total occupancy count of the channel by calling the hereNow() function in your application.

Cache

This method has a 3 second response cache time.

Method(s)​

To call Here Now you can use the following method(s) in the Swift SDK:

func hereNow(
    on channels: [String],
    and groups: [String] = [],
    includeUUIDs: Bool = true,
    includeState: Bool = false,
    custom requestConfig: PubNub.RequestConfiguration = PubNub.RequestConfiguration(),
    completion: ((Result<[String: PubNubPresence], Error>) -> Void)?
)
* required
ParameterDescription
on *
Type: [String]
Default:
n/a
The list of channels to return occupancy results from.
and
Type: [String]
Default:
[]
The list of channel groups for which will return occupancy results from.
includeUUIDs
Type: Bool
Default:
true
Setting uuid to false disables the return of UUIDs.
includeState
Type: Bool
Default:
false
Setting this flag to true will return the subscribe state information as well.
custom
Type: PubNub.RequestConfiguration
Default:
PubNub.RequestConfiguration()
An object that allows for per-request customization of PubNub Configuration or Network Session.
completion
Type: ((Result<[String: PubNubPresence], Error>) -> Void)?
Default:
nil
The async Result of the method call.

Completion Handler Result​

Success​

A Dictionary of channels mapped to their respective PubNubPresence

public protocol PubNubPresence {

    /// The channel identifier
    var channel: String { get }

    /// The total number of UUIDs present on the channel
    var occupancy: Int { get set }

    /// The known UUIDs present on the channel
    ///
    /// The `count` of this Array may differ from the `occupancy` field
    var occupants: [String] { get set }

    /// The Dictionary of UUIDs mapped to their respective presence state data
    var occupantsState: [String: JSONCodable] { get set }
show all 16 lines
Failure​

An Error describing the failure.

Basic Usage​

Get a list of UUIDs subscribed to channel​

Reference code

This example is a self-contained code snippet ready to be run. It includes necessary imports and executes methods with console logging. Use it as a reference when working with other examples in this document.


Other Examples​

Return Occupancy Only​

Requires Presence

This method requires that the Presence add-on is enabled for your key in the Admin Portal.

You can return only the occupancy information for a single channel by specifying the channel and setting UUIDs to false:


Channel Group Usage​

Requires Presence

This method requires that the Presence add-on is enabled for your key in the Admin Portal.


Where Now​

Requires Presence

This method requires that the Presence add-on is enabled for your key in the Admin Portal.

You can obtain information about the current list of channels to which a UUID is subscribed to by calling the whereNow() function in your application.

Timeout events

If the app is killed/crashes and restarted (or the page containing the PubNub instance is refreshed on the browser) within the heartbeat window no timeout event is generated.

Method(s)​

To call whereNow() you can use the following method(s) in the Swift SDK:

func whereNow(
    for uuid: String,
    custom requestConfig: PubNub.RequestConfiguration = PubNub.RequestConfiguration(),
    completion: `((Result<[String: [String]], Error>) -> Void)?`
)
* required
ParameterDescription
for *
Type: String
Default:
n/a
Specifies the UUID to return channel list for.
custom
Default:
PubNub.RequestConfiguration()
An object that allows for per-request customization of PubNub configuration or network session. For more information, refer to the Request Configuration section.
completion
Type: ((Result<[String: [String]], Error>) -> Void)?
Default:
nil
The async Result of the method call.

Completion Handler Result​

Success​

A Dictionary of UUIDs mapped to their respective Array of channels they have presence on.

Failure​

An Error describing the failure.

Basic Usage​

You simply need to define the uuid and the callback function to be used to send the data to as in the example below.

Get a list of channels a UUID is subscribed to​


User State​

Requires Presence

This method requires that the Presence add-on is enabled for your key in the Admin Portal.

Clients can set a dynamic custom state (score, game state, location) for their users on one or more channels and store it on a channel as long as the user stays subscribed.

The state is not persisted, and when the client disconnects, the state data is lost. For more information, refer to Presence State.

Method(s)​

Set State​

func setPresence(
    state: [String: JSONCodableScalar],
    on channels: [String],
    and groups: [String] = [],
    custom requestConfig: PubNub.RequestConfiguration = PubNub.RequestConfiguration(),
    completion: ((Result<JSONCodable, Error>) -> Void)?
)
* required
ParameterDescription
state *
Type: [String: JSONCodableScalar]
Default:
n/a
The state Dictionary to store. Nesting of Dictionary values isn't permitted, and key names beginning with prefix pn are reserved. Setting the state will overwrite the previous values set. Clearing out the state involves passing in an empty Dictionary.
on
Type: [String]
Default:
n/a
The list of channel to set the state on. Pass an empty array to not set.
and
Type: [String]
Default:
n/a
The list of channel groups to set the state on.
custom
Default:
PubNub.RequestConfiguration()
An object that allows for per-request customization of PubNub configuration or network session. For more information, refer to the Request Configuration section.
completion
Type: ((Result<JSONCodable, Error>) -> Void)?
Default:
nil
The async Result of the method call.

Completion Handler Result​

Success​

The presence State set as a JSONCodable.

Failure​

An Error describing the failure.

Get State​

func getPresenceState(
    for uuid: String,
    on channels: [String],
    and groups: [String] = [],
    custom requestConfig: PubNub.RequestConfiguration = PubNub.RequestConfiguration(),
    completion: ((Result<(uuid: String, stateByChannel: [String: JSONCodable]), Error>) -> Void)?
)
* required
ParameterDescription
for *
Type: String
Default:
n/a
The UUID to retrieve the state for.
on
Type: [String]
Default:
n/a
The list of channel to get the state on. Pass an empty array to not get.
and
Type: [String]
Default:
[]
The list of channel groups to get the state on. Pass an empty array to not get.
custom
Default:
PubNub.RequestConfiguration()
An object that allows for per-request customization of PubNub configuration or network session. For more information, refer to the Request Configuration section.
completion
Type: ((Result<(uuid: String, stateByChannel: [String: JSONCodable]), Error>) -> Void)?
Default:
nil
The async Result of the method call.

Completion Handler Result​

Success​

A Tuple containing the UUID that set the State and a Dictionary of channels mapped to their respective State.

Failure​

An Error describing the failure.

Basic Usage​

Set State​


Get State​


Other Examples​

Converting the response to a JSON Dictionary​


Converting the response to a custom object​


Last updated on
On this page