Presence API for C# 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.

Request execution

We recommend using try and catch statements when working with the C# SDK.

If there's an issue with the provided API parameter values, like missing a required parameter, the SDK throws an exception. However, if there is a server-side API execution issue or a network problem, the error details are contained within the status.

try
{
    PNResult<PNPublishResult> publishResponse = await pubnub.Publish()
        .Message("Why do Java developers wear glasses? Because they can't C#.")
        .Channel("my_channel")
        .ExecuteAsync();

    PNStatus status = publishResponse.Status;

    Console.WriteLine("Server status code : " + status.StatusCode.ToString());
}
catch (Exception ex)
{
    Console.WriteLine($"Request can't be executed due to error: {ex.Message}");
}

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.

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 C# SDK:

pubnub.HereNow()
        .Channels(Array)
        .ChannelGroups(Array)
        .IncludeState(bool)
        .IncludeUUIDs(bool)
        .QueryParam(Dictionary<string,object>)
* required
ParameterDescription
Channels
Type: Array
The Channels to get the here now details.
ChannelGroups
Type: Array
The ChannelGroups to get the here now details.
IncludeState
Type: bool
If true, the response will include the presence states of the users for Channels/ChannelGroups.
IncludeUUIDs
Type: bool
If true, the response will include the UUIDs of the connected clients.
QueryParam
Type: Dictionary<string, object>
Dictionary object to pass name/value pairs as query string params with PubNub URL request for debug purpose.
Async
Type: PNCallback
PNCallback of type PNHereNowResult.

This parameter is deprecated and will be removed in a future version. Please use the ExecuteAsync parameter instead.
Execute *
Type: PNCallback
PNCallback of type PNHereNowResult.
ExecuteAsync
Type: None
Returns PNResult<PNHereNowResult>.

Sample code​

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.

Get a list of UUIDs subscribed to channel​


Returns​

The HereNow() operation returns a PNResult<PNHereNowResult> which contains the following properties:

Property NameTypeDescription
Result
PNHereNowResult
Returns a PNHereNowResult object.
Status
PNStatus
Returns a PNStatus object.

PNHereNowResult contains the following properties:

Property NameTypeDescription
TotalChannels
int
Total Channels.
TotalOccupancy
int
Total Occupancy.
Channels
Dictionary<string, PNHereNowChannelData>
A map with values of PNHereNowChannelData for each channel. See PNHereNowChannelData for more details.

PNHereNowChannelData​

Property NameTypeDescription
ChannelName
string
Channel name.
Occupancy
int
Occupancy of the channel.
Occupants
List<PNHereNowOccupantData>
A list of PNHereNowOccupantData, see PNHereNowOccupantData for more details.

PNHereNowOccupantData​

Property NameTypeDescription
Uuid
string
UUIDs of the user.
State
object
State of the user.

Other examples​

Get a list of UUIDs subscribed to channel synchronously​


Returning 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.


Example response​

{
    "status" : 200,
    "message" : "OK",
    "service" : "Presence",
    "uuids" : [
        {
            "uuid" : "myUUID0"
        },
        {
            "state" : {
                "abcd" : {
                    "age" : 15
                }
            },
            "uuid" : "myUUID1"
show all 38 lines

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:


Example response​

{
    "status": 200,
    "message": "OK",
    "payload": {
        "channels": {
            "81d8d989-b95f-443c-a726-04fac323b331": {
                "uuids": [ "70fc1140-22b5-4abc-85b2-ff8c17b24d59" ],
                "occupancy": 1
            },
            "81b7a746-d153-49e2-ab70-3037a75cec7e": {
                "uuids": [ "91363e7f-584b-49cc-822c-52c2c01e5928" ],
                "occupancy": 1
            },
            "c068d15e-772a-4bcd-aa27-f920b7a4eaa8": {
                "uuids": [ "ccfac1dd-b3a5-4afd-9fd9-db11aeb65395" ],
show all 23 lines

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.

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 C# SDK:

pubnub.WhereNow()
        .Uuid(string)
        .QueryParam(Dictionary<string,object>)
* required
ParameterDescription
Uuid *
Type: string
Uuid.
QueryParam
Type: Dictionary<string, object>
Dictionary object to pass name/value pairs as query string params with PubNub URL request for debug purpose.
Async
Type: PNCallback
PNCallback of type PNWhereNowResult.

This parameter is deprecated and will be removed in a future version. Please use the ExecuteAsync parameter instead.
Execute *
Type: Command
PNCallback of type PNWhereNowResult.
ExecuteAsync
Type: None
Returns PNResult<PNWhereNowResult>.

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​


Returns​

The WhereNow() operation returns a PNResult<PNWhereNowResult> which contain the following properties:

Property NameTypeDescription
Result
PNWhereNowResult
Returns a PNWhereNowResult object.
Status
PNStatus
Returns a PNStatus object.

PNWhereNowResult contains the following properties:

Property NameTypeDescription
Channels
List<string>
The list of channels where the UUID is present.

Other examples​

Get a list of channels synchronously​


Obtain information about the current list of channels of some other UUID​


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.

The state API is used to set/get key/value pairs specific to a subscriber Uuid.

State information is supplied as a Generic Dictionary object(Dictionary<string, object>) of key/value pairs.

Method(s)​

Set state​

pubnub.SetPresenceState()
        .Channels(Array)
        .ChannelGroups(Array)
        .State(Dictionary<string, object>)
        .Uuid(string)
        .QueryParam(Dictionary<string,object>)
* required
ParameterDescription
Channels
Type: Array
Channels to set state.
ChannelGroups
Type: Array
ChannelGroups to set state.
State
Type: Dictionary<string, object>
State to set.
Uuid *
Type: string
Uuid
QueryParam
Type: Dictionary<string, object>
Dictionary object to pass name/value pairs as query string params with PubNub URL request for debug purpose.
Async
Type: PNCallback
PNCallback of type PNSetStateResult.

This parameter is deprecated and will be removed in a future version. Please use the ExecuteAsync parameter instead.
Execute *
Type: PNCallback
PNCallback of type PNSetStateResult.
ExecuteAsync
Type: None
Returns PNResult<PNSetStateResult>.

Get state​

pubnub.GetPresenceState()
        .Channels(Array)
        .ChannelGroups(Array)
        .Uuid(string)
        .QueryParam(Dictionary<string,object>)
* required
ParameterDescription
Channels
Type: Array
Channel name to fetch the state.
ChannelGroups
Type: Array
ChannelGroups name to fetch the state.
Uuid *
Type: string
Uuid
QueryParam
Type: Dictionary<string, object>
Dictionary object to pass name/value pairs as query string params with PubNub URL request for debug purpose.
Async
Type: PNCallback
PNCallback of type PNGetStateResult.

This parameter is deprecated and will be removed in a future version. Please use the ExecuteAsync parameter instead.
Execute *
Type: PNCallback
PNCallback of type PNGetStateResult.
ExecuteAsync
Type: None
Returns PNResult<PNGetStateResult>.

Sample code​

Set state​


Get state​


Returns​

The SetPresenceState() operation returns a PNResult<PNSetStateResult> which contains the following properties:

Property NameTypeDescription
Result
PNGetStateResult
Returns a PNSetStateResult object.
Status
PNStatus
Returns a PNStatus object.

PNSetStateResult contains the following property:

Property NameTypeDescription
State
Dictionary<string, object>
Dictionary of UUIDs and the user states.

The GetPresenceState() operation returns a PNResult<PNGetStateResult> which contains the following properties:

Property NameTypeDescription
Result
PNGetStateResult
Returns a PNGetStateResult object.
Status
PNStatus
Returns a PNStatus object.

PNGetStateResult contains the following property:

Property NameTypeDescription
StateByUUID
Dictionary<string, object>
Dictionary of UUIDs and the user states.

Other examples​

Set state synchronously​


Get state synchronously​


Set state for channels in channel group​


The above code would return the following response to the client:

{
    first  : "Robert",
    last   : "Plant",
    age    : 59,
    region : "UK"
}
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