How to reserve ZIO response inside a custom method in - scala

Question

I have this method
import ClientServer.*
import zio.http.{Client, *}
import zio.json.*
import zio.http.model.Method
import zio.{ExitCode, URIO, ZIO}
import sttp.capabilities.*
import sttp.client3.Request
import zio.*
import zio.http.model.Headers.Header
import zio.http.model.Version.Http_1_0
import zio.stream.*
import java.net.InetAddress
import sttp.model.sse.ServerSentEvent
import sttp.client3._
object fillFileWithLeagues:
def fill = for {
openDotaResponse <- Client.request("https://api.opendota.com/api/leagues")
bodyOfResponse <- openDotaResponse.body.asString
listOfLeagues <- ZIO.fromEither(bodyOfResponse.fromJson[List[League]].left.map(error => new Exception(error)))
save = FileStorage.saveToFile(listOfLeagues.toJson) //Ok
}yield ()
println("Im here fillFileWithLeagues.fill ")
and when I try use
fillFileWithLeagues.fill
nothing happens
I'm trying fill file with data from target api using
fillFileWithLeagues.fill
def readFromFileV8(path: Path = Path("src", "main", "resources", "data.json")): ZIO[Any, Throwable, String] =
val zioStr = (for bool <- Files.isReadable(path) yield bool).flatMap(bool =>
if (bool) Files.readAllLines(path, Charset.Standard.utf8).map(_.head)
else {
fillFileWithLeagues.fill
wait(10000)
println("im here readFromFileV8")
readFromFileV8()})
zioStr
I'm expecting data.json file must created from
Client.request("https://api.opendota.com/api/leagues")
but there is nothing happens
Maybe I should use some sttp, or some other tools?

Answer 1

If we fix indentation of the code we'll find this:
object fillFileWithLeagues {
def fill = {
for {
openDotaResponse <- Client.request("https://api.opendota.com/api/leagues")
bodyOfResponse <- openDotaResponse.body.asString
listOfLeagues <- ZIO.fromEither(bodyOfResponse.fromJson[List[League]].left.map(error => new Exception(error)))
save = FileStorage.saveToFile(listOfLeagues.toJson) //Ok
} yield ()
}
println("Im here fillFileWithLeagues.fill ")
}
As you see the println is part of fillFileWithLeagues, not of fill.
Another potential problem is that an expression like fillFileWithLeagues.fill only returns a ZIO instance, it is not yet evaluated. To evaluate it, it needs to be run. For example as follows:
import zio._
object MainApp extends ZIOAppDefault {
def run = fillFileWithLeagues.fill
}