Presence

In your chat app, you might want to graphically show up-to-date information on all users present on a given channel, showing if they are online, offline, active, or away.

Unity Chat SDK provides methods and options to determine user's presence on the channel level. To do that, Unity Chat SDK uses the PubNub Presence API. It provides a set of convenience methods for checking which channels a given user is subscribed to. Importantly, you can stream presence events and always get real-time information about the user's channel presence. You can also set dynamic custom state for users on one or more channels. This custom state persists on a channel as long as the user stays subscribed. Some examples of custom states are to add your score, game state, or location in an application if it changes frequently.

Channel presence

These methods let you monitor who is subscribed to a given channel ("present" on that channel).

Requires Presence

All channel presence methods in this section require that Presence is enabled for your app's keyset in the Admin Portal.

You can retrieve similar information for presence with different methods by calling them on the User, Channel, or Chat object. Depending on the chosen method, you must provide a different input information set.

Return channels where user is present

You can return a list of channels where a given user is present with:

WherePresent() called on the User object
WherePresent() called on the Chat object.

Both of these methods have the same name and give the same output. The only difference is that you call a given method either on the Chat or the User object. Depending on the object, you either have to specify the ID of the user whose presence you want to check or not because it's already known.

Method signature

These methods take the following parameters:

WherePresent() (on the User object)
```
user.WherePresent()
```
WherePresent() (on the Chat object)
```
chat.WherePresent(
    string userId
)
```

Input

Parameter	Type	Required in the `User` object method	Required in the `Chat` object method	Default	Description
`userId`	`string`	No	Yes	n/a	Unique identifier (up to 92 UTF-8 characters) of the user whose presence you want to check.

Output

This method returns a List<string> with all channel IDs on which the given user is present.

Basic usage

Get a list of channels on which the support_agent_15 user is present.

WherePresent() (on the User object)

if (!chat.TryGetUser("support_agent_15`", out var user))
{
    Console.WriteLine("Couldn't find user!");
    return;
};

var channelIds = user.WherePresent()

WherePresent() (on the Chat object)

// reference the "chat" object and invoke the "wherePresent()" method.
var channelIds = chat.WherePresent("support_agent_15")

Check user's channel presence

You can return information if the user is present on a specified channel with:

IsPresentOn() called on the User object
IsUserPresent() called on the Channel object.
IsPresent() called on the Chat object.

All of these methods give the same output. The only difference is that you call a given method on the User, Channel, or Chat object. Depending on the object, you have to specify the ID of the user whose presence you want to check, the channel ID where you want to check user's presence, or both user and channel IDs.

Method signature

These methods take the following parameters:

IsPresentOn() (on the User object)
```
user.IsPresentOn(
    string channelId
)
```

IsUserPresent() (on the Channel object)

channel.IsUserPresent(
    string userId
)

IsPresent() (on the Chat object)

chat.IsPresent(
    string userId, 
    string channelId
)

Input

Parameter	Type	Required in the `User` object method	Required in the `Channel` object method	Required in the `Chat` object method	Default	Description
`userId`	`string`	No	Yes	Yes	n/a	Unique ID (up to 92 UTF-8 characters) of the user whose presence you want to check.
`channelId`	`string`	Yes	No	Yes	n/a	Unique identifier of the channel where you want to check the user's presence.

Output

Returns information on whether a given user is present on a specified channel (true) or not (false).

Basic usage

Find out if the support_agent_15 user is present on the support channel.

IsPresentOn() (on the User object)

if (!chat.TryGetUser("support_agent_15`", out var user))
{
    Console.WriteLine("Couldn't find user!");
    return;
};

var isPresentOn = user.IsPresentOn("support")

IsUserPresent() (on the Channel object)

if (!chat.TryGetChannel("support", out var channel))
{
    Console.WriteLine("Couldn't find channel!");
    return;
};

var isPresent = channel.IsUserPresent("support_agent_15")

IsPresent() (on the Chat object)

var isPresent = chat.IsPresent("support_agent_15", "support")

Return all users present on channel

You can return a list of users present on the given channel with:

WhoIsPresent() called on the Channel object
WhoIsPresent() called on the Chat object.

Both of these methods have the same name and give the same output. The only difference is that you call a given method either on the Chat or the Channel object. Depending on the object, you either have to specify the ID of the channel where you want to check all present users or not because it's already known.

Method signature

These methods take the following parameters:

WhoIsPresent() (on the Channel object)
```
channel.WhoIsPresent()
```
WhoIsPresent() (on the Chat object)
```
chat.WhoIsPresent(
    string channelId
)
```

Input

Parameter	Type	Required in the `Channel` object method	Required in the `Chat` object method	Default	Description
`channelId`	`string`	No	Yes	n/a	Unique identifier of the channel where you want to check all present users.

Output

This method returns a List<string> with all user IDs on the channel.

Basic usage

Get a list of users that are present on the support channel.

WhoIsPresent() (on the Channel object)

if (!chat.TryGetChannel("support", out var channel))
{
    Console.WriteLine("Couldn't find channel!");
    return;
};

var userIds = channel.WhoIsPresent()

WhoIsPresent() (on the Chat object)

var userIds = chat.WhoIsPresent("support")

Get presence updates

Get up-to-date information about the real-time presence of users in the specified channel by subscribing to PubNub Presence events. The OnPresenceUpdate event lets you constantly track who connects to or disconnects from the channel and visually represent that in your chat app through some status, like offline, online, active, away, or any other.

Event signature

Action<List<string>> OnPresenceUpdate;

Event handler signature

void EventHandler(List<string> users)

Parameter	Type	Required	Default	Description
`users`	`List<string>`	Yes	n/a	List of user IDs.

Basic usage

Get user presence updates on support channel.

if (!chat.TryGetChannel("support", out var channel))
{
    Console.WriteLine("Couldn't find channel!");
    return;
};

channel.OnPresenceUpdate += OnPresenceUpdateHandler; // or use lambda

void OnPresenceUpdateHandler(List<string> users)
{
    Console.WriteLine($"Users present: {string.Join(", ", users)}");
}

Channel presence​

Requires Presence

Return channels where user is present​

Method signature​

Input​

Output​

Basic usage​

Check user's channel presence​

Method signature​

Input​

Output​

Basic usage​

Return all users present on channel​

Method signature​

Input​

Output​

Basic usage​

Get presence updates​

Event signature​

Event handler signature​

Basic usage​

Channel presence

Return channels where user is present

Method signature

Input

Output

Basic usage

Check user's channel presence

Method signature

Input

Output

Basic usage

Return all users present on channel

Method signature

Input

Output

Basic usage

Get presence updates

Event signature

Event handler signature

Basic usage