Channel Groups API for Kotlin SDK

Breaking changes in v9.0.0

PubNub Kotlin SDK version 9.0.0 unifies the codebases for Kotlin and Java SDKs, introduces a new way of instantiating the PubNub client, and changes asynchronous API callbacks and emitted status events. These changes can impact applications built with previous versions (< 9.0.0 ) of the Kotlin SDK.

For more details about what has changed, refer to Java/Kotlin SDK migration guide.

Channel groups allow PubNub developers to bundle thousands of channels into a group that can be identified by a name. These channel groups can then be subscribed to, receiving data from the many back-end channels the channel group contains.

Channel group operations

You can't publish to a channel group. You can only subscribe to it. To publish within the channel group, you need to publish to each channel individually.

Request execution

Most PubNub Kotlin SDK method invocations return an Endpoint object, which allows you to decide whether to perform the operation synchronously or asynchronously.

You must invoke the .sync() or .async() method on the Endpoint to execute the request, or the operation will not be performed.

val channel = pubnub.channel("channelName")

channel.publish("This SDK rules!").async { result ->
    result.onFailure { exception ->
        // Handle error
    }.onSuccess { value ->
        // Handle successful method result
    }
}

Add channels to a channel group

Requires Stream Controller add-on

This method requires that the Stream Controller add-on is enabled for your key in the PubNub Admin Portal. Read the support page on enabling add-on features on your keys.

This function adds channels to a channel group.

Method(s)

Use the following method in the Kotlin SDK:

Maximum number of channels

You can add up to 200 channels to a channel group per API call.

pubnub.addChannelsToChannelGroup(
    channelGroup: String,
    channels: List<String>
).async { result -> }

* required

Parameter	Description
channelGroup * Type: String	The channel group to add the channels to.
channels * Type: List<String>	The channels to add to the channel group.

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.

Response

The addChannelsToChannelGroup() doesn't return actionable data, be sure to check result object on the outcome of the operation by checking the result.isFailure or handling exception result.onFailure(exception -> { }).

List channels in a channel group

Requires Stream Controller add-on

This method requires that the Stream Controller add-on is enabled for your key in the Admin Portal. Read the support page on enabling add-on features on your keys.

This function lists all channels in a channel group.

Method(s)

Use the following method in the Kotlin SDK:

pubnub.listChannelsForChannelGroup(
    channelGroup: String
).async { result -> }

* required

Parameter	Description
channelGroup * Type: String	The channel group for which to list channels.

Sample code

Returns

The listChannelsForChannelGroup() operation returns a PNChannelGroupsAllChannelsResult which contains the following operations:

Method	Description
channels Type: List<String>	List of channels of a channel group.

Remove channels from a channel group

Requires Stream Controller add-on

This method requires that the Stream Controller add-on is enabled for your key in the Admin Portal. Read the support page on enabling add-on features on your keys.

This function removes channels from a channel group.

Method(s)

Use the following method in the Kotlin SDK:

pubnub.removeChannelsFromChannelGroup(
    channels: List<String>,
    channelGroup: String
).async { result -> }

* required

Parameter	Description
channels * Type: List<String>	The channels to remove from the channel group.
channelGroup * Type: String	The channel group from which to remove channels.

Sample code

Returns

The removeChannelsFromChannelGroup() doesn't return actionable data, be sure to check result object on the outcome of the operation by checking the result.isFailure or handling exception result.onFailure(exception -> { }).

Delete a channel group

Requires Stream Controller add-on

This method requires that the Stream Controller add-on is enabled for your key in the Admin Portal. Read the support page on enabling add-on features on your keys.

This function deletes a channel group.

Method(s)

Use the following method in the Kotlin SDK:

pubnub.deleteChannelGroup(
    channelGroup: String
).async { result -> }

* required

Parameter	Description
channelGroup * Type: String	The channel group to delete.

Sample code

Returns

The deleteChannelGroup() doesn't return actionable data, be sure to check result object on the outcome of the operation by checking the result.isFailure or handling exception result.onFailure(exception -> { }).