Group call

This page explains the key functions of group call consisting of how to create a room and how a user can participate in a group call by entering and exiting a room from your app.

You can choose to create a room that supports up to 6 participants with video or a room that supports up to 100 participants with audio. When a user creates a room in your app, the room’s status becomes OPEN and a ROOM_ID is generated.

You can create a room by setting the room type by using the Type property and the createRoom() method as shown below.

let roomType = RoomType.smallRoomForVideo
let params = RoomParams(roomType: roomType)
SendBirdCall.createRoom(with: params) { room, error in
    guard let room = room, error == nil else { return } // Handle error.
    // `room` is created with a unique identifier `room.roomId`.
}

A user can search a room with a specific room ID to participate in a group call at any time. When a user enters a room, a participant is created with a unique participant ID to represent the user in the room.

To enter a room, you must acquire the room instance from Sendbird server with the room ID. To fetch the most up-to-date room instance from Sendbird server, use the SendBirdCall.fetchRoom(by:completionHandler:) method. Also, you can use the SendBirdCall.getCachedRoom(by:) method that returns the most recently cached room instance from Sendbird Calls SDK.

SendBirdCall.fetchRoom(by: ROOM_ID) { room, error in
    guard let room = room, error == nil else { return } // Handle error.
    // `room` with the identifier `ROOM_ID` is fetched from Sendbird Server.
}

let cachedRoom: Room? = SendBirdCall.getCachedRoom(by: ROOM_ID)
// Returns the most recently cached room from the SDK.
//If there is no such room with the given room ID, `nil` is returned.

Note: A user can enter the room using multiple devices or browser tabs. Entering from each device or browser tab will create a new participant.

Once the room is retrieved, call the enter(with:completionHandler:) method to enter the room.

let params = Room.EnterParams(isVideoEnabled: true, isAudioEnabled: true)
room.enter(with: params) { error in
    guard error == nil else { return } // Handle error.
    // User has successfully entered `room`.
}

Note: Share the room ID with other users for them to enter the room from the client app.

To leave a room, call Room.exit(). On the room delegates of the remaining participants, the RoomDelegate.didRemoteParticipantExit(_:) method will be called.

do {
    try room.exit()
    // participant has exited the room successfully.
} catch {
    // SBCError.participantNotInRoom is thrown because participant has not entered the room.
}

With custom items for group calls, you can store additional information as key-value pairs to a room in the Room object. Custom key-value items are saved as a [String: String] dictionary and can be updated or deleted as long as the room status is OPEN. Information related to customer service, refund, or inquiry can be added as custom items for better user experience.

When a room is created, users can add custom items in RoomParams as [String: String] dictionary type. By default, the customItems is an empty dictionary.

let customItems = [“key”: “value1”, “key2”: “value2”]
let params = RoomParams(roomType: .smallRoomForVideo, customItems: customItems)
SendBirdCall.createRoom(with: params) { room, error in
    // Set up delegates to receive events.
 }

Custom items can be updated or deleted as long as the room status is OPEN. If a new custom item has the same key as the existing custom item, the new item will update the value of the existing item. A new item with a new key will be added to the list of custom items. You can update existing custom items by calling the room.updateCustomItems(customItems:completionHandler:).

You can delete custom items by calling the room.deleteCustomItems(customItemKeys:completionHandler:) with the list of keys that you want to delete from the list of custom items.

let customItems = [“key1”: “value3”]
room.updateCustomItems(customItems: customItems, completionHandler: { customItems, updatedKeys, error in
    // Custom items with matching keys in `updatedKeys` have been updated in the `customItems`.
})

let keys = [“key1”]
room.deleteCustomItems(customItemKeys: keys, completionHandler: { customItems, deletedKeys, error in
     // Custom items with matching keys in `deletedKeys` have been deleted from `customItems`.
})

A participant in a room can receive events from Sendbird server when other participants update or delete custom items in the room. Implement the didUpdateCustomItems(updatedKeys:) and the didDeleteCustomItems(deletedKeys:) from the RoomDelegate to receive events from other participants. Each event contains the list of keys of the changed custom items, such as updatedKeys or deletedKeys.

Custom items can be modified and the events are delivered to the RoomDelegate only when the room's status is OPEN and there are participants in the room. To check the custom items that had been changed for ended or ongoing calls in a room, you can use the Calls API or room.fetchCustomItems(completionHandler:).

class MyClass: RoomDelegate {
  func didUpdateCustomItems(updatedKeys: [String]) {
      // Custom items with `updatedKeys` have been updated in the target room.
  }
  func didDeleteCustomItems(deletedKeys: [String]) {
      // Custom items with `deletedKeys` have been deleted in the target room.
  }
}

You can retrieve a list of rooms by using the RoomListQuery and the following table shows all supported filters for the RoomListQuery to search for specific rooms you want to retrieve.

You can specify the above filters as shown below:

let params = RoomListQuery.Params()
            .setType(.largeRoomForAudioOnly)
            .setLimit(50)
            .setState(.open)
            .setRangeForCurrentParticipantCount(3...)
            .setCreatedByUserIds([USER_ID1, USERID2])
            .setRangeForCreatedAt(..<Date())

To retrieve a list of rooms, call the RoomListQuery.next(completionHandler:) method.

let query = SendBirdCall.createRoomListQuery(with: params)
if query?.hasNext == true, query?.isLoading == false {
    query?.next{ rooms, error in
        guard let rooms = rooms, error == nil else {
            // Error has occurred.
            return
        }
        ...
    }
}

When a list of rooms is retrieved, you can show the list to a user and allow the user to select a room they want to enter.

rooms.first?.enter(with: .init()) { error in
    // User has entered the room.
}

Note: The room data returned from the query is not updated unless the user has entered the room. To update the details about a room, call the SendBirdCall.fetchRoom(by:completionHandler:) method.

Participant’s actions, such as turning on or off their microphone or camera, in a room are handled by the participant objects.

To control the media of the local user, you can use the following methods from the Room.localParticipant object:

// Mutes the local participant's microphone.
room.localParticipant.muteMicrophone()

// Unmutes the local participant's microphone.
room.localParticipant.unmuteMicrophone()

// Stops the local participant's video.
room.localParticipant.stopVideo()

// Starts the local participant's video.
room.localParticipant.startVideo()

// Switches between the front and back camera.
room.localParticipant.switchCamera(completionHandler: ErrorHandler)

When there is a participant in the room, a media stream is established between a participant and Sendbird server to support group calls. You can configure the user interface for participants in a room by using the properties in Participant.

The following is the process of how participants can send and receive media streams in a room:

Step 1: To send a media stream, a participant who would like to send its media stream has to be connected to Sendbird server.

Step 2: To receive a media stream, a participant who would like to receive a media stream from another participant has to be connected to the media server. Once connected, the didRemoteParticipantStreamStart(_:) method will be invoked which notifies that the receiving media stream has started.

Step 3: Add a view to show the received media stream.

class MyClass: RoomDelegate {
    // Called when a remote participant is connected to the media stream and starts sending the media stream.
    func didRemoteParticipantStreamStart(_ participant: RemoteParticipant) { }
}

You can receive a video stream from a participant by configuring the videoView property as shown below:

@IBOutlet weak var participantVideoView: UIView?

// Create SendBirdVideoView.
let participantSendBirdVideoView = SendBirdVideoView(frame: self.participantVideoView?.frame ?? CGRect.zero)
self.participantVideoView?.embed(participantSendBirdVideoView)

// Configure participants video view.
// participant: Participant
participant.videoView = participantSendBirdVideoView

You can show participants in gallery view as they enter or exit the room by using UICollectionView which dynamically changes views. You can set the number of items to be the count of room.participants and the custom cells to represent each participant.

When the below methods in RoomDelegate are called, information for room.participants gets updated and the number of items are changed accordingly. To have the custom cells added or removed, you need to call UICollectionView.reloadData() for the delegate methods.

If a participant is not connected to the call or has turned off their video, you can set a default image to show on the screen for that participant. Otherwise, it will be shown as black to other participants. To check whether a participant has turned on their video or is connected to the room for a video call, refer to the isVideoEnabled and the state properties of a Participant object.

It is recommended to show an image such as the user’s profile image as the default image when the didRemoteParticipantEnter(_:) delegate method is invoked.

When the didRemoteParticipantStreamStart(_:) delegate method is invoked, create a new UIImageView and set it to the participant by adding it as a subview on the UITableView or UICollectionView cell.

A user can receive events of a room that they are currently participating. Users will be notified when other participants enter or leave the room, change their media settings or when the room is deleted.

Add an event delegate for the user to receive events that occur in a room that the user joins as a participant.

room.addDelegate(myClass, identifier: UNIQUE_IDENTIFIER)

class MyClass: RoomDelegate {
}

When a participant joins or leaves the room, other participants in the room will receive the following events.

class MyClass: RoomDelegate {
    // Called when a remote participant has entered the room.
    func didRemoteParticipantEnter(_ participant: RemoteParticipant) { }

    // Called when a remote participant has exited the room.
    func didRemoteParticipantExit(_ participant: RemoteParticipant) { }
}

A local participant can change the media settings such as muting their microphone or turning off their camera by using muteMicrophone() or stopVideo(). Other participants will receive event delegates that notify them of the corresponding media setting changes.

class MyClass: RoomDelegate {
 // Called when audio settings of a remote participant have been changed.
    func didRemoteAudioSettingsChange(_ participant: RemoteParticipant) { }

    // Called when video settings of a remote participant have been changed.
    func didRemoteVideoSettingsChange(_ participant: RemoteParticipant) { }
}

To delete a room through Calls Platform API, see Delete a room in the Calls API documentation. When a room is deleted, participants in the room will receive the following event.

class MyRoom: RoomDelegate {
    // Called when the room has been deleted.
    func didDelete() { }
}

To stop receiving events about a room, remove the registered delegates as shown below:

// Removes registered delegate that has the matching identifier.
room.removeDelegate(identifier: UNIQUE_IDENTIFIER)

// Removes all registered delegates to stop receiving events about a room.
room.removeAllDelegates()

When a participant loses media stream in a room due to connection issues, Sendbird Calls SDK automatically tries to reconnect the participant’s media streaming in the room. If the Calls SDK fails to reconnect for about 40 seconds, an error will be returned.

class MyClass: RoomDelegate {
    // Called when an error has occurred.
    func didReceiveError(_ error: SBCError, participant: Participant?) {
        // Clear resources for group calls.
    }
}

Note: See the Error codes page for more information.