URI handling
Literals
http4s is a bit more strict with handling URIs than e.g. the play http client.
Instead of passing plain String
s, http4s operates on URIs. You can construct
literal URI with
import org.http4s._
import org.http4s.implicits._
val uri = uri"http://http4s.org"
// uri: Uri = Uri(
// Some(Scheme(http)),
// Some(Authority(None, RegName(http4s.org), None)),
// "",
// ,
// None
// )
Building URIs
Naturally, that’s not enough if you want dynamic URIs. There’s a few different
ways to build URIs, you can either use a predefined URI and call methods on it,
or you could use the URLTemplates.
URI
Use the methods on the uri class.
val docs = uri.withPath("/docs/0.15")
// docs: Uri = Uri(
// Some(Scheme(http)),
// Some(Authority(None, RegName(http4s.org), None)),
// "/docs/0.15",
// ,
// None
// )
val docs2 = uri / "docs" / "0.15"
// docs2: Uri = Uri(
// Some(Scheme(http)),
// Some(Authority(None, RegName(http4s.org), None)),
// "/docs/0.15",
// ,
// None
// )
assert(docs == docs2)
URI Template
import org.http4s.UriTemplate._
val template = UriTemplate(
authority = Some(Uri.Authority(host = Uri.RegName("http4s.org"))),
scheme = Some(Uri.Scheme.http),
path = List(PathElm("docs"), PathElm("0.15"))
)
// template: UriTemplate = UriTemplate(
// Some(Scheme(http)),
// Some(Authority(None, RegName(http4s.org), None)),
// List(PathElm("docs"), PathElm("0.15")),
// List(),
// List()
// )
template.toUriIfPossible
// res1: scala.util.Try[Uri] = Success(
// Uri(
// Some(Scheme(http)),
// Some(Authority(None, RegName(http4s.org), None)),
// "/docs/0.15",
// ,
// None
// )
// )
Receiving URIs
URIs come in as strings from external routes or as data. Http4s provides
encoders/decoders for Uri
in the connector packages. If you want to build your
own, use Uri.fromString
.
For example one for knobs:
implicit val configuredUri = Configured[String].flatMap(s => Configured(_ => Uri.fromString(s).toOption))