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

Parameter	Description
`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`.
`Execute` * Type: PNCallback	`PNCallback` of type `PNHereNowResult`.
`ExecuteAsync` Type: None	Returns `PNResult<PNHereNowResult>`.

Basic Usage

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

using System;
using PubnubApi;
using System.Threading.Tasks;
using System.Collections.Generic;

class HereNowExample
{
    static async Task Main(string[] args)
    {
        // Configuration
        PNConfiguration pnConfiguration = new PNConfiguration(new UserId("myUniqueUserId"))
        {
            SubscribeKey = "demo",
            PublishKey = "demo",
            Secure = true
show all 59 lines

Returns

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

Property Name	Type	Description
`Result`	PNHereNowResult	Returns a `PNHereNowResult` object.
`Status`	PNStatus	Returns a `PNStatus` object.

PNHereNowResult contains the following properties:

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

PNHereNowOccupantData

Property Name	Type	Description
`Uuid`	string	`UUIDs` of the user.
`State`	object	`State` of the user.

Other Examples

Get a list of UUIDs subscribed to channel synchronously

pubnub.HereNow()
    // tailor the next two lines to example
    .Channels(new string[] {
        "coolChannel",
        "coolChannel2"
        })
    .IncludeUUIDs(true)
    .Execute(new PNHereNowResultEx(
        (result, status) => {
            if (status.Error) {
                // handle error
                return;
            }

            if (result.Channels != null && result.Channels.Count > 0) {
show all 33 lines

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.

PNResult<PNHereNowResult> herenowResponse = await pubnub.HereNow()
    .Channels(new string[] {
        // who is present on those channels?
        "my_channel"
    })
    .IncludeState(true) // include state with request (false by default)
    .IncludeUUIDs(true) // if false, only shows occupancy count
    .ExecuteAsync();

PNHereNowResult herenowResult = herenowResponse.Result;
PNStatus status = herenowResponse.Status;
//handle it

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:

PNResult<PNHereNowResult> herenowResponse = await pubnub.HereNow()
    .Channels(new string[] {
            // who is present on those channels?
        "my_channel"
    })
    .IncludeState(false) // include state with request (false by default)
    .IncludeUUIDs(false) // if false, only shows occupancy count
    .ExecuteAsync();

PNHereNowResult herenowResult = herenowResponse.Result;
PNStatus status = herenowResponse.Status;
//handle it

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

Parameter	Description
`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: Command	`PNCallback` of type `PNWhereNowResult`.
`Execute` * Type: Command	`PNCallback` of type `PNWhereNowResult`.
`ExecuteAsync` Type: None	Returns `PNResult<PNWhereNowResult>`.

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

PNResult<PNWhereNowResult> wherenowResponse = await pubnub.WhereNow()
    .ExecuteAsync();

PNWhereNowResult wherenowResult = wherenowResponse.Result;
PNStatus status = wherenowResponse.Status;
// returns a pojo with channels
// channel groups which I am part of.

Returns

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

Property Name	Type	Description
`Result`	PNWhereNowResult	Returns a `PNWhereNowResult` object.
`Status`	PNStatus	Returns a `PNStatus` object.

PNWhereNowResult contains the following properties:

Property Name	Type	Description
`Channels`	List`<string>`	The list of `channels` where the `UUID` is present.

Other Examples

Get a list of channels synchronously

pubnub.WhereNow()
    .Execute(new PNWhereNowResultExt(
        (result, status) => {
            // returns a pojo with channels
            // channel groups which I am part of.
        }
    ));

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

PNResult<PNWhereNowResult> wherenowResponse = await pubnub.WhereNow()
    .Uuid("some-other-uuid") // uuid of the user we want to spy on.
    .ExecuteAsync();

PNWhereNowResult wherenowResult = wherenowResponse.Result;
PNStatus status = wherenowResponse.Status;
// returns a pojo with channels
// channel groups which "some-other-uuid" part of.ere_now_example_1

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

Parameter	Description
`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`.
`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

Parameter	Description
`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`.
`Execute` * Type: PNCallback	`PNCallback` of type `PNGetStateResult`.
`ExecuteAsync` Type: None	Returns PNResult`<PNGetStateResult>`.

Basic Usage

Set State

Dictionary<string, object> myState = new Dictionary<string, object>();
myState.Add("age", 20);

PNResult<PNSetStateResult> setstateResponse = await pubnub.SetPresenceState()
    .Channels(new string[] {
        "ch1",
        "ch2",
        "ch3"
    })
    .State(myState)
    .ExecuteAsync();

PNSetStateResult setstateResult = setstateResponse.Result;
PNStatus status = setstateResponse.Status;
// handle set state response

Get State

PNResult<NGetStateResult> getstateResponse = await pubnub.GetPresenceState()
    .Channels(new string[] {
        // channels to fetch state for
        "ch1",
        "ch2",
        "ch3"
    })
    .ChannelGroups(new string[] {
        // channel groups to fetch state for
        "cg1",
        "cg2",
        "cg3"
    })
    .Uuid("suchUUID") // uuid of user to fetch, or for own uuid
    .ExecuteAsync();
show all 19 lines

Returns

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

Property Name	Type	Description
`Result`	PNGetStateResult	Returns a `PNSetStateResult` object.
`Status`	PNStatus	Returns a `PNStatus` object.

PNSetStateResult contains the following property:

Property Name	Type	Description
`State`	Dictionary`<string, object>`	Dictionary of `UUIDs` and the user states.

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

Property Name	Type	Description
`Result`	PNGetStateResult	Returns a `PNGetStateResult` object.
`Status`	PNStatus	Returns a `PNStatus` object.

PNGetStateResult contains the following property:

Property Name	Type	Description
`StateByUUID`	Dictionary`<string, object>`	Dictionary of `UUIDs` and the user states.

Other Examples

Set state synchronously

Dictionary<string, object> myState = new Dictionary<string, object>();
myState.Add("age", 20);

pubnub.SetPresenceState()
    .Channels(new string[] {
        "ch1",
        "ch2",
        "ch3"
    })
    .State(myState)
    .Execute(new PNSetStateResultExt(
        (result, status) => {
            // handle set state response
        }
    ));

Get state synchronously

pubnub.GetPresenceState()
    .Channels(new string[] {
        // channels to fetch state for
        "ch1",
        "ch2",
        "ch3"
    })
    .ChannelGroups(new string[] {
        // channel groups to fetch state for
        "cg1",
        "cg2",
        "cg3"
    })
    .Uuid("suchUUID") // uuid of user to fetch, or for own uuid
    .Execute(new PNGetStateResultExt(
show all 19 lines

Set state for channels in channel group

Dictionary<string, object> myState = new Dictionary<string, object>();
myState.Add("age", 20);

PNResult<PNSetStateResult> setstateResponse = await pubnub.SetPresenceState()
    .ChannelGroups(new string[] {
        // apply on those channel groups
        "cg1",
        "cg2",
        "cg3"
    })
    .Channels(new string[] {
        // apply on those channels
        "ch1",
        "ch2",
        "ch3"
show all 22 lines

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

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

Request execution

Here Now​

Requires Presence

Cache

Method(s)​

Basic Usage​

Reference code

Get a list of UUIDs subscribed to channel​

Returns​

PNHereNowChannelData​

PNHereNowOccupantData​

Other Examples​

Get a list of UUIDs subscribed to channel synchronously​

Returning State​

Requires Presence

Example Response​

Return Occupancy Only​

Requires Presence

Example Response​

Where Now​

Requires Presence

Timeout events

Method(s)​

Basic Usage​

Get a list of channels a UUID is subscribed to​

Returns​

Other Examples​

Get a list of channels synchronously​

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

User State​

Requires Presence

Method(s)​

Set State​

Get State​

Basic Usage​

Set State​

Get State​

Returns​

Other Examples​

Set state synchronously​

Get state synchronously​

Set state for channels in channel group​

Here Now

Method(s)

Basic Usage

Get a list of UUIDs subscribed to channel

Returns

PNHereNowChannelData

PNHereNowOccupantData

Other Examples

Get a list of UUIDs subscribed to channel synchronously

Returning State

Example Response

Return Occupancy Only

Example Response

Where Now

Method(s)

Basic Usage

Get a list of channels a UUID is subscribed to

Returns

Other Examples

Get a list of channels synchronously

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

User State

Method(s)

Set State

Get State

Basic Usage

Set State

Get State

Returns

Other Examples

Set state synchronously

Get state synchronously

Set state for channels in channel group