Collection of extensions for Telegramium (a pure functional Telegram Bot API implementation for Scala) that I use to build my bots.
tgbot-utils is currently available for Scala 2.12 and 2.13.
Whole utils pack:
libraryDependencies += "ru.johnspade" %% "tgbot-utils" % "<latest version in badge>"
A specific module:
libraryDependencies += "ru.johnspade" %% "<module name>" % "<latest version in badge>"
Represent your callback query data types as an ADT and use kantan.csv to (de)serialize them to CSV strings.
import kantan.csv.DecodeError.TypeError
import kantan.csv.ops._
import kantan.csv._
import ru.johnspade.tgbot.callbackdata.named.MagnoliaRowEncoder._
import ru.johnspade.tgbot.callbackdata.named.MagnoliaRowDecoder._
sealed abstract class CallbackData {
def toCsv: String = this.writeCsvRow(rfc)
}
final case class BuyIcecream(flavor: String) extends CallbackData
case object SayHello extends CallbackData
object CallbackData {
implicit val buyIcecreamRowCodec: RowCodec[BuyIcecream] = RowCodec.caseOrdered(BuyIcecream.apply _)(BuyIcecream.unapply)
implicit val sayHelloRowCodec: RowCodec[SayHello.type] = RowCodec.from(_ => Right(SayHello))(_ => Seq.empty)
def decode(csv: String): ReadResult[CallbackData] =
csv.readCsv[List, CallbackData](rfc).headOption.getOrElse(Left(TypeError("Callback data is missing")))
}
val csv = BuyIcecream("vanilla").toCsv
// BuyIceCream,vanilla
val callbackData = CallbackData.decode(csv).getOrElse(sys.error(""))
// BuyIcecream(vanilla)
http4s -like DSL to handle callback queries.
import cats.effect.IO
import ru.johnspade.tgbot.callbackqueries.CallbackQueryDsl._
import ru.johnspade.tgbot.callbackqueries.CallbackQueryRoutes
import telegramium.bots.client.Method
val routes = CallbackQueryRoutes.of[CallbackData, Option[Method[_]], IO] {
case BuyIcecream(flavor) in cb =>
IO {
println(s"${cb.from.firstName} have chosen: $flavor")
None
}
}
Extract and use context information from callback queries with CallbackQueryContextRoutes
:
import cats.effect.IO
import ru.johnspade.tgbot.callbackqueries.CallbackQueryDsl._
import ru.johnspade.tgbot.callbackqueries.CallbackQueryContextRoutes
import telegramium.bots.high.Methods
case class User(id: Int, firstName: String, language: String)
val contextRoutes = CallbackQueryContextRoutes.of[CallbackData, User, Option[Method[_]], IO] {
case SayHello in cb as user =>
IO {
Some(Methods.answerCallbackQuery(cb.id, text = Some(s"Hello, ${user.firstName}")))
}
}
We use CallbackQueryContextMiddleware
for that:
import cats.data.{Kleisli, OptionT}
import ru.johnspade.tgbot.callbackqueries.{CallbackQueryContextMiddleware, CallbackQueryData, ContextCallbackQuery}
val userMiddleware: CallbackQueryContextMiddleware[CallbackData, User, Option[Method[_]], IO] =
_.compose(
Kleisli { (cb: CallbackQueryData[CallbackData]) =>
val from = cb.cb.from
val user = User(from.id, from.firstName, from.languageCode.getOrElse("en"))
OptionT.liftF(IO(ContextCallbackQuery(user, cb)))
}
)
Combine multiple routes with <+>
(combineK
) and handle queries with CallbackQueryHandler
:
import cats.syntax.semigroupk._
import cats.syntax.either._
import ru.johnspade.tgbot.callbackqueries.{CallbackQueryHandler, CallbackDataDecoder, ParseError, DecodeError}
val allRoutes = routes <+> userMiddleware(contextRoutes)
private val cbDataDecoder: CallbackDataDecoder[IO, CallbackData] =
CallbackData.decode(_).left.map {
case error: kantan.csv.ParseError => ParseError(error.getMessage)
case error: kantan.csv.DecodeError => DecodeError(error.getMessage)
}
.toEitherT[IO]
// query: CallbackQuery
val handler = CallbackQueryHandler.handle(
query,
routes = allRoutes,
decoder = cbDataDecoder,
onNotFound = _ => IO(Option.empty[Method[_]])
)
String interpolators to create message entities with auto-calculated offsets and lenghts.
import ru.johnspade.tgbot.messageentities.TypedMessageEntity
import ru.johnspade.tgbot.messageentities.TypedMessageEntity.Plain.lineBreak
import ru.johnspade.tgbot.messageentities.TypedMessageEntity._
val messageEntities = List(
plain"bold: ", bold"bold text", lineBreak,
plain"italic: ", italic"italic text", lineBreak,
plain"email: ", email"do-not-reply@telegram.org", lineBreak,
plain"pre: ", Pre(text = "monowidth block", language = "Scala")
)
val tgMessageEntities = TypedMessageEntity.toMessageEntities(messageEntities)
/*
List(
BoldMessageEntity(6,9),
ItalicMessageEntity(24,11),
EmailMessageEntity(43,25),
PreMessageEntity(74,15,Scala)
)
*/
val text = messageEntities.map(_.text).mkString
/*
bold: bold text
italic: italic text
email: do-not-reply@telegram.org
pre: monowidth block
*/