Message Reactions API for PubNub 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.

Add or remove actions on published messages to build features like receipts, reactions, or to associate custom metadata to messages. Clients can subscribe to a channel to receive message reaction events on that channel. They can also fetch past message reactions from Message Persistence independently or when they fetch original messages.

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
    }
}

Terminology

All message reactions in code are collectively called message reactions in the docs and the term applies both to reacting to a message (through emojis) and acting on a message (by deleting it).

Add Message Reaction

Requires Message Persistence

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

Add an action on a published message. Returns the added action in the response.

Method(s)

To Add a Message Reaction you can use the following method(s) in the Kotlin SDK:

pubnub.addMessageAction(
    channel: String,
    messageAction: PNMessageAction
).async { result -> }

Parameter	Type	Required	Description
channel	String	Yes	Specifies channel name to publish message reactions to.
messageAction	PNMessageAction	Yes	The message reaction object containing the message reaction's type, value and the publish timetoken of the original message. See PNMessageAction for more details.

Basic Usage

pubnub.addMessageAction(
    channel = "my_channel",
    messageAction = PNMessageAction(
        type = "reaction",
        value = "smiley_face",
        messageTimetoken = 15701761818730000L
    )
).async { result ->
    result.onFailure { exception ->
        // Handle error
    }.onSuccess { value ->
        // Handle successful method result
    }
}

Returns

The addMessageAction() operation returns a PNAddMessageActionResult which contains the following operations:

Method	Type	Description
type	String	Message reaction's type.
value	String	Message reaction's value.
uuid	String	Publisher of the message reaction.
actionTimetoken	String	Timestamp when the message reaction was created.
messageTimetoken	Long	Timestamp when the actual message was created the message reaction belongs to.

PNMessageAction

Method	Type	Description
type	String	Message reaction's type.
value	String	Message reaction's value.
messageTimetoken	Long	Timestamp when the actual message was created the message reaction belongs to.

Remove Message Reaction

Requires Message Persistence

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

Remove a previously added action on a published message. Returns an empty response.

Method(s)

To Remove a Message Reaction you can use the following method(s) in the Kotlin SDK:

pubnub.removeMessageAction(
    channel: String,
    messageTimetoken: Long,
    actionTimetoken: Long
).async { result -> }

Parameter	Type	Required	Description
channel	String	Yes	Specifies channel name to remove message reactions from.
messageTimetoken	Long	Yes	Publish timetoken of the original message.
actionTimetoken	Long	Yes	Publish timetoken of the message reaction to be removed.

Basic Usage

pubnub.removeMessageAction(
    channel = "my_channel",
    messageTimetoken = 15701761818730000L,
    actionTimetoken = 15701775691010000L
).async { _, status ->
    if (!status.error) {
        // result has no actionable data
        // it's enough to check if the status itself is not an error
    } else {
        // handle error
        status.exception?.printStackTrace()
    }
}

Returns

The removeMessageAction() operation returns a no actionable data.

Get Message Reactions

Requires Message Persistence

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

Get a list of message reactions in a channel. Returns a list of actions sorted by the action's timetoken in ascending order.

Method(s)

To Get Message Reactions you can use the following method(s) in the Kotlin SDK:

pubnub.getMessageActions(
    channel: String,
    page: PNBoundedPage
)

Parameter	Type	Required	Description
channel	String	Yes	The channel name.
page	PNBoundedPage	Optional	The paging object used for pagination. Set limit to specify the number of actions to return in response. Default/Maximum is 100. start and end denotes the range boundaries. Return values will be less than start and greater or equal to end.

Basic Usage

pubnub.getMessageActions(
    channel = "my_channel"
).async { result ->
    result.onFailure { exception ->
        // Handle error
    }.onSuccess { value ->
        // Handle successful method result
    }
}

Returns

The getMessageActions() operation returns a list of PNGetMessageActionsResult? objects, each containing the following operations:

Method	Type	Description
type	String	Message reaction's type.
value	String	Message reaction's value.
uuid	String	Publisher of the message reaction.
actionTimetoken	String	Timestamp when the message reaction was created.
messageTimetoken	Long	Timestamp when the actual message was created the message reaction belongs to.
page	PNBoundedPage	If exists indicates that more data is available. It can be passed directly to another call of getMessageActions to retrieve this remaining data.

Other Examples

Fetch Messages with paging

fun main() {
    getMessageActionsWithPaging(
        channel = "my_channel",
        start = System.currentTimeMillis() * 10_000L
    ) { actions ->
        actions.forEach {
            println(it.type)
            println(it.value)
            println(it.uuid)
            println(it.messageTimetoken)
            println(it.actionTimetoken)
        }
    }
}

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