Kotlin Telegram Bot

Kotlin based wrapper over Telegram API.

Installation

Add the MavenCentral repository to your root build.gradle.kts file:

repositories {
    mavenCentral()
}

Now add the library itself to the dependencies' module that you need it.

dependencies {
    implementation("eu.vendeli:telegram-bot:2.0.1")
}

Samples

You can see the samples in the samples' folder there you can find:

• Conversation - An example of using Inputs and storing data in UserData.
• Echo - Echo bot :)
• Exception-handling - Simple example of exception handling
• Ktor-webhook - An example of using webhook with Ktor
• Poll - An example of how to build a bot questionnaire.

Usage

suspend fun main() {
    val bot = TelegramBot("BOT_TOKEN", "com.example.controllers")
    /**
     * Second parameter is the package in which commands/inputs will be searched.
     */

    bot.handleUpdates()
    // start long-polling listener
}

@CommandHandler(["/start"])
suspend fun start(user: User, bot: TelegramBot) {
    message { "Hello" }.send(to = user, via = bot)
}

It is also possible to process manually:

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

    bot.handleUpdates { update ->
        onCommand("/start") {
            message { "Hello, what's your name?" }.send(user, bot)
            bot.inputListener.set(user.id, "conversation")
        }
        inputChain("conversation") {
            message { "Nice to meet you, ${message.text}" }.send(user, bot)
            message { "What is your favorite food?" }.send(user, bot)
        }.breakIf({ message.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 {
            // ...
        }
    }
}

It is also possible to do more advanced processing with a manual listener setting with bot.update.setListener {} function.

for webhook handling you can use any server and bot.update.handle() function (or use this function if you're directly setting listener),
and for set webhook you can use this method:

setWebhook("https://site.com").send(bot)

if you want to operate with response you can use sendAsync() instead of send() method, which returns Response:

message { "test" }.sendAsync(user, bot).await().onFailure {
    println("code: ${it.errorCode} description: ${it.description}")
}

Any async request returns a Response on which you can also use methods getOrNull() , isSuccess() , onFailure() .

More about

You can also read more information in the wiki, and you're always welcome in chat.