HelloController.groovy

package mn.telegram

import io.micronaut.http.MediaType;
import io.micronaut.http.annotation.Controller;
import io.micronaut.http.annotation.Get;
import io.micronaut.http.annotation.Produces;
import javax.inject.Inject
import com.puravida.mn.telegram.*

@Controller("/hello") 
public class HelloController {

    @Inject
    TelegramBot telegramBot

    @Get("/") 
    @Produces(MediaType.TEXT_PLAIN) 
    public String index() {

	Message message = new Message(chat_id:"-1001382561920",text:"hola from telegram api")
        telegramBot.sendMessage(message).subscribe({ ok->
		byte[] image = "http://mars.jpl.nasa.gov/msl-raw-images/proj/msl/redops/ods/surface/sol/01000/opgs/edr/fcam/FLB_486265257EDR_F0481570FHAZ00323M_.JPG".toURL().bytes
		SendPhoto photo = new SendPhoto(chat_id:"-1001382561920",bytes:image)
		telegramBot.sendPhoto(photo.multipartBody()).subscribe()
	},{ error->
		println error
	})

        return "Hello World"; 
    }
}

workshop-bot.adoc

Workshop: Build a Telegram Bot with Micronaut

Requirements

• Docker

• Java/Groovy

• Telegram in your mobile phone

• Heroku account and Heroku cli installed

Theory

• Architecture

• Channel

• Chat

• Others (not covered in this workshop): games, money

• Bot

  • push

  • pull

BotFather

• create bot

• config bot

• keep your Token secret

Channel

• Public vs Private

• Sending messages to a channel

• Sending multimedia to a channel

Chat

• Dockerize and publish to Heroku

• Starting a chat

• Answering to the user

• Sending multimedia to the user

• Commands and Keyboards

• InlineKeyboards and Callbacks

• Dialog

Heroku Alternatives

• Google AppEngine (Grails)

• Google Run

• Digital Ocean

• Okteto