Why do I get LocalDateTime error in Scala? - scala

Question

Im trying to build a small web page for my school project in scala with cask. Im trying to use the LocalDateTime data type in my forms and in the post handlers. For some reason I get this error when trying to run the website:
could not find implicit value for parameter p: annotObject$macro$24.InputParser[java.time.LocalDateTime]
[error] def f (name: String, location: String, team: String, begins: LocalDateTime, ends: LocalDateTime, info: String) = {
I have no clue what's going on, any help is appreciated. This is my code:
import backend.Session
import backend.test.Test._
import scalatags.Text.all.{borderWidth, link, marginBottom, p, _}
import java.time.LocalDateTime
object MinimalApplication extends cask.MainRoutes{
basicUser()
var session = new Session(None, false)
#cask.postForm("/createEvent")
def f (name: String, location: String, team: String, begins: LocalDateTime, ends: LocalDateTime, info: String) = {
createEvent.post(name, location, team, begins, ends, info)
}
#cask.get("/createEvent")
def e () = createEvent.get()
initialize()
}
And the handlers look like this:
import scalatags.Text.all.{form, p, _}
import java.time.LocalDateTime
object createEvent {
def get() = {
html(
head(
link(
rel := "stylesheet",
href := "https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/css/bootstrap.min.css"
),
),
body(
div(width := "50%",height := "100vh", display := "flex", flexDirection := "column", padding := "50px", borderWidth :="3px", borderStyle:="solid", borderColor := "black", marginLeft := "25%")(
h1(marginBottom:="100px", alignSelf := "center")("Create a new event"),
form(action := "/createEvent", method := "post")(
div(width := "100%", height := "100%", display := "flex", justifyContent := "center", alignItems := "flex-start", flexDirection := "column", alignSelf:="center")(
input(
marginBottom := "10px",
`type` := "text",
name := "name",
placeholder := "Event name",
width := "70%",
borderWidth := "2px",
borderStyle := "solid",
backgroundColor := "White",
borderColor := "(240, 240, 240)",
borderRadius := "5px"
// userName.map(value := _)
),
input(
`type` := "text",
name := "location",
placeholder := "Location",
width := "50%",
borderWidth := "2px",
borderStyle := "solid",
backgroundColor := "White",
borderColor := "(240, 240, 240)",
borderRadius := "5px",
marginBottom := "10px"
// msg.map(value := _)
)
,
input(
`type` := "text",
name := "team",
placeholder := "Team",
width := "25%",
borderWidth := "2px",
borderStyle := "solid",
backgroundColor := "White",
borderColor := "(240, 240, 240)",
borderRadius := "5px",
marginBottom := "10px"
// msg.map(value := _)
),
div(display := "flex")(
div(display:= "flex", flexDirection := "column", marginRight := "20px")(
h6()("Begins"),
input(
`type` :="datetime-local",
min:="2021-11-12T19:30",
value := s"${LocalDateTime.now()}",
name := "begins",
width := "100%",
height := "30px",
borderWidth := "2px",
borderStyle := "solid",
backgroundColor := "White",
borderColor := "(240, 240, 240)",
borderRadius := "5px",
marginBottom := "10px"
)
),
div(display:= "flex", flexDirection := "column")(
h6()("Ends"),
input(
`type` :="datetime-local",
min:="2021-11-12T19:30",
value := s"${LocalDateTime.now()}",
name := "ends",
width := "100%",
height := "30px",
borderWidth := "2px",
borderStyle := "solid",
backgroundColor := "White",
borderColor := "(240, 240, 240)",
borderRadius := "5px",
marginBottom := "10px"
)
)
),
textarea(
`type` := "text",
name := "info",
placeholder := "Info",
width := "70%",
height := "150px",
borderWidth := "2px",
borderStyle := "solid",
backgroundColor := "White",
borderColor := "(240, 240, 240)",
borderRadius := "5px",
marginBottom := "10px"
// msg.map(value := _)
),
button(
alignSelf := "center",
`type` := "submit",
width := "15%",
height := "30px",
marginTop := "20px",
borderWidth := "1px",
borderStyle := "solid",
backgroundColor := "light-grey",
borderColor := "Black",
borderRadius := "5px")("Create")
)
)
)
)
)
}
def post(name: String, location: String, team: String, begins: LocalDateTime, ends: LocalDateTime, info: String) = {
if(name.nonEmpty && location.nonEmpty && team.nonEmpty) {
html(
head(),
body(
p()(s"nimi: ${name}"),
p()(s"paikka: ${location}"),
p()(s"tiimi: ${team}"),
p()(s"alkaa: ${begins}"),
p()(s"loppuu: ${ends}"),
p()(s"info: ${info}")
)
)
}
}
}

Answer 1

could not find implicit value for parameter p: InputParser[java.time.LocalDateTime]
You get the error because Cask doesn't know how to read a LocalDateTime from a request.
One way to solve the issue is to implement a implicit val reader: InputParser[LocalDateTime] = ???, or maybe Cask provides it through some other library or imports?
Another way is to read the parameters as regular Strings and do the parsing yourself in the f method.