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Presence API for Swift Native SDK

Presence lets you track who is online or offline and store custom state information. Presence shows:

When a user has joined or left a channel
How many users are subscribed to a particular channel (occupancy)
Which channels a user or device is subscribed to
Presence state associated with these users

Learn more about our Presence feature in the Presence overview.

Here now

Requires Presence

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

For information on how to receive presence events and what those events are, refer to Presence Events.

This method returns information about the current state of a channel, including a list of unique user IDs (universally unique identifiers, UUIDs) currently subscribed to the channel and the total occupancy count of the channel.

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:

1func 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)?
8)

* required

Parameter	Description
`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. Wildcards are not supported.
`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

1public protocol PubNubPresence {
2

3    /// The channel identifier
4    var channel: String { get }
5

6    /// The total number of UUIDs present on the channel
7    var occupancy: Int { get set }
8

9    /// The known UUIDs present on the channel
10    ///
11    /// The `count` of this Array may differ from the `occupancy` field
12    var occupants: [String] { get set }
13

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

Failure

An Error describing the failure.

Sample code

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.

For information on how to receive presence events and what those events are, refer to Presence Events.

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.

For information on how to receive presence events and what those events are, refer to Presence Events.

Where now

Requires Presence

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

For information on how to receive presence events and what those events are, refer to Presence Events.

This method returns the list of channels a UUID is subscribed to.

Timeout events

If the app restarts (or the page refreshes) 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:

1func whereNow(
2    for uuid: String,
3    custom requestConfig: PubNub.RequestConfiguration = PubNub.RequestConfiguration(),
4    completion: `((Result<[String: [String]], Error>) -> Void)?`
5)

* required

Parameter	Description
`for` * Type: String Default: n/a	Specifies the `UUID` to return channel list for.
`custom` Type: `PubNub.RequestConfiguration` 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.

Sample code

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.

For information on how to receive presence events and what those events are, refer to Presence Events.

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

1func setPresence(
  state: [String: JSONCodableScalar],
  on channels: [String],
  and groups: [String] = [],
  custom requestConfig: PubNub.RequestConfiguration = PubNub.RequestConfiguration(),
  completion: ((Result<JSONCodable, Error>) -> Void)?
7)

* required

Parameter	Description
`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` Type: `PubNub.RequestConfiguration` 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

1func 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)?
7)

* required

Parameter	Description
`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` Type: `PubNub.RequestConfiguration` 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.

Here now​

Requires Presence

Cache

Method(s)​

Completion handler result​

Success​

Failure​

Sample code​

Get a list of UUIDs subscribed to channel​

Reference code

Other examples​

Return occupancy only​

Requires Presence

Channel group usage​

Requires Presence

Where now​

Requires Presence

Timeout events

Method(s)​

Completion handler result​

Success​

Failure​

Sample code​

Get a list of channels a UUID is subscribed to​

User state​

Requires Presence

Method(s)​

Set state​

Completion handler result​

Success​

Failure​

Get state​

Completion handler result​

Success​

Failure​

Sample code​

Set state​

Get state​

Other examples​

Converting the response to a JSON dictionary​

Converting the response to a custom object​

Here now

Method(s)

Completion handler result

Success

Failure

Sample code

Get a list of UUIDs subscribed to channel

Other examples

Return occupancy only

Channel group usage

Where now

Method(s)

Completion handler result

Success

Failure

Sample code

Get a list of channels a UUID is subscribed to

User state

Method(s)

Set state

Completion handler result

Success

Failure

Get state

Completion handler result

Success

Failure

Sample code

Set state

Get state

Other examples

Converting the response to a JSON dictionary

Converting the response to a custom object