Functional DSL

To infinity functional handling and beyond!

Although the basic mechanism of working with the bot involves working with annotations, but nevertheless it does not prevent the use of functional update processing.

Moreover, the flexibility of the bot interface also allows you to combine the two modes.

Functional handling DSL

In most functional processing methods differ in the types of Update supported, in simple terms you can put a listener on a certain type of data.

By way of example:

suspend fun main() {
    val bot = TelegramBot("BOT_TOKEN")

    bot.handleUpdates() {
        onChosenInlineResult {
            println("got a result ${update.chosenInlineResult.resultId} from ${update.user}")
        }
    }
}

Commands and Inputs

It is also possible to process both commands and inputs.

See example:

fun main() = runBlocking {
    val bot = TelegramBot("BOT_TOKEN")

    bot.handleUpdates() {
            // regular command
        onCommand("/start") {
            message { "Hello" }.send(user, bot)
        }
        onCommand("""(red|green|blue)""".toRegex()) {
            message { "you typed ${update.text} color" }.send(user, bot)
        }
    }
}

In the context of the onCommand function, parameters in the format Map<String, String> are passed,
parsed appropriately specified in configuration.

Inputs

It is also possible to use inputs through the familiar bot.inputListener mechanism.

fun main() = runBlocking {
    val bot = TelegramBot("BOT_TOKEN")

    bot.handleUpdates() {
            // regular command
        onCommand("/start") {
            message { "Hello, what's your name?" }.send(user, bot)
            bot.inputListener[user] = "testInput"
        }
        onInput("testInput") {
            message { "Hey, nice to meet you, ${update.text}" }.send(user, bot)
        }
    }
}

Also, you can use input chaining:

inputChain("conversation") {
     message { "Nice to meet you, ${update.text}" }.send(user, bot)
     message { "What is your favorite food?" }.send(user, bot)
}.breakIf({ update.text == "peanut butter" }) { // chain break condition
     message { "Oh, too bad, I'm allergic to it." }.send(user, bot)
     // action that will be applied when match
}.andThen {
     // next input point if break condition doesn't match
}

You can read more about methods in the FunctionalHandlingDsl class documentation.

Caution

Be aware that if you use both processors (functional, annotation) inputs may work not as it seems to be (each processor clears input after being processed, if you want another behavior change inputAutoRemoval configuration).

See also

• Action
• Useful utilities