Activites and Processors

Introduction

Activity in the terms of this library is the abstract entity that serves as concept that represents a generalization of entities such as @CommandHandler, @InputHandler, @UnprocessedHandler, and @CommonHandler.

Also take a look at handlers article.

Collecting activities

Activities are collected and prepared all context in compile time.

If you want to limit the area in which the package will be searched, you can pass a parameter to plugin:

ktGram {
    packages = listOf("com.example.mybot")
}

or without plugin through ksp:

ksp {
    arg("package", "com.example.mybot")
}

note in such a case, in order for the collected actions to be processed correctly, you must also specify the package in the instance itself.

fun main() = runBlocking {
    val bot = TelegramBot("BOT_TOKEN", "com.example.mybot")

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

this option is added to be able to run multiple bot instances:

ktGram {
    packages = listOf("com.example.mybot", "com.example.mybot2")
}

or if you're not using plugin to specify different packages you need to specify them with ; separator:

ksp {
    arg("package", "com.example.mybot;com.example.mybot2")
}

Processors

You have two types of flow processing updates:

Functional

You establish the processing behavior through the lambda parameter function bot.handleUpdates() {}, or through bot.update.setListener.

You can read more about functional processing in a related article.

See FunctionalHandlingDsl.

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

    bot.handleUpdates {
         onMessage {
             message { update.text }.send(update.user, bot)
         }
   }
}

Annotation

Annotation depends on the selected processing mode:

Webhooks

In your controller (or another place where the webhook is processed), you call: bot.update.parseAndHandle(webhookString)

By default it will use processor for annotations, but if you want to have some custom behaviour it also can be set through setBehaviour (it is not necessary to assign the behavior in the controller itself every time, it is enough to assign it once during configuration):

bot.update.setBehaviour {
   // ...any other actions
   update(it) // run annotation processor
}

Long polling

Call: bot.handleUpdates() or through bot.update.setListener { handle(it) }

Both

Also, if desired, both these approaches can be combined using the same setListener {}, in such an approach even the same command can be processed twice, processing will be done in the order they are called.

fun main() = runBlocking {
    val bot = TelegramBot("BOT_TOKEN", "eu.vendeli.samples.controller")

    bot.update.setListener {
        handle(it) // Here we send the update for annotation processing.
        handle(it) { // Here we functionally process it afterwards.
            onMessage {
                message { update.text }.send(update.user, bot)
            }
        }
}

Example of combining usage you can see in a poll sample.

or in webhook handling you can set through setBehaviour as described before.

See also

• Update parsing
• Activity invocation
• Actions