Hello! I want to convert an ISO date format into a...

# compose-web

[Partho Paul]

Hello!
I want to convert an ISO date format into a given format. I'm doing it using JSJoda library as below:

val date = LocalDateTime.parse(isoValue)
val dateFormat = DateTimeFormatter.ofPattern(format)
return date.format(dateFormat)

This is giving me an error which says that DateTimeFormatter.ofPattern(format) needs a Locale but I'm not getting any option to set Locale by doing something like DateTimeFormatter.ofPattern(format).withLocale(Locale.ENGLISH) because Locale is just an interface without any implementation. Tried googling but didn't find anything. Is there any other way to do this?

TIA

[rocketraman]

If you want to use JSJoda, check out: https://js-joda.github.io/js-joda/manual/formatting.html

[rocketraman]

In my project I created an expect/actual for date/time formatting. My JS implementation uses Date.toLocaleTimeString and looks like this:

actual fun formatDateTime(date: LocalDateTime, locale: String): String =
  jsFormatDateTime(date.year, date.monthNumber - 1, date.dayOfMonth, date.hour, date.minute, locale)

@Suppress("UNUSED_PARAMETER", "LongParameterList")
private fun jsFormatDateTime(yearArg: Int, monthArg: Int, dayArg: Int, hourArg: Int, minuteArg: Int, locale: String): String =
  js(
    "(new Date(yearArg, monthArg, dayArg, hourArg, minuteArg))" +
      ".toLocaleTimeString(locale, {year: 'numeric', month: 'short', day: '2-digit'});"
  ) as String

[rocketraman]

Where locale is just a standard locale string e.g. en-US.

[Luc Girardin]

FYI, you can do all of this in pure Kotlin using Klock (https://docs.korge.org/klock/). At least this worked well for me…

[Partho Paul]

@Luc Girardin This works for me. Thank you!
@rocketraman Thanks for showing a different approach

[rocketraman]

Hopefully kotlinx-datetime will introduce formatting functions before long