Presence API for Lua 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

Here now

Requires Presence

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

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 Lua SDK:

pubnub_obj:here_now(params)

* required

Parameter	Description
params * Type: table	Table of here-now parameters. See Here Now Parameters for more details.

Here now parameters

* required

Parameter	Description
channel Type: string Default: none	The channel to get presence for - if not provided, get global presence.
callback * Type: function(r) Default: none	The function to call on success with result.
error Type: function(r) Default: function(r) end	The function to call on failure, with result.

Sample code

Get a list of uuids subscribed to channel

pubnub_obj:here_now({
    channel = "demo",
    callback = function(response)
        textout(response)
    end,
    error = function (response)
        textout(response)
    end
})

Where now

Requires Presence

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

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 where_now() you can use the following method(s) in the Lua SDK:

pubnub_obj:where_now(params)

* required

Parameter	Description
params * Type: table	Table of where-now parameters. See Where Now Parameters for more details.

Where now parameters

* required

Parameter	Description
UUID Type: string Default: UUID of the object	The UUID to get presence for.
callback * Type: function(r) Default: none	The function to call on success with result.
error Type: function(r) Default: function(r) end	The function to call on failure, with result.

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

pubnub_obj:where_now({
    callback = function(response)
        textout(response)
    end,
    error = function (response)
        textout(response)
    end
})