=htc #18518 make it simpler to unmarshal csv values from params

akka-docs-dev/rst/scala/code/docs/http/scaladsl/server/directives/ParameterDirectivesExamplesSpec.scala

@@ -7,8 +7,9 @@ package directives
 
 import akka.http.scaladsl.model._
 import akka.http.scaladsl.server.Route
+import akka.http.scaladsl.unmarshalling.PredefinedFromStringUnmarshallers
 
-class ParameterDirectivesExamplesSpec extends RoutingSpec {
+class ParameterDirectivesExamplesSpec extends RoutingSpec with PredefinedFromStringUnmarshallers {
   "example-1" in {
     val route =
       parameter('color) { color =>
@@ -180,4 +181,17 @@ class ParameterDirectivesExamplesSpec extends RoutingSpec {
       responseAs[String] shouldEqual "The parameters are x = '1', x = '2'"
     }
   }
+  "csv" in {
+    val route =
+      parameter("names".as(CsvString)) { names =>
+        complete(s"The parameters are ${names.mkString(", ")}")
+      }
+
+    Get("/?names=Caplin") ~> route ~> check {
+      responseAs[String] shouldEqual "The parameters are Caplin"
+    }
+    Get("/?names=Caplin,John") ~> route ~> check {
+      responseAs[String] shouldEqual "The parameters are Caplin, John"
+    }
+  }
 }

akka-docs-dev/rst/scala/http/routing-dsl/directives/parameter-directives/parameters.rst

@@ -94,6 +94,12 @@ Repeated parameter
 .. includecode2:: ../../../../code/docs/http/scaladsl/server/directives/ParameterDirectivesExamplesSpec.scala
    :snippet: repeated
 
+Csv valued parameter
+++++++++++++++++++++
+
+.. includecode2:: ../../../../code/docs/http/scaladsl/server/directives/ParameterDirectivesExamplesSpec.scala
+   :snippet: csv
+
 Repeated, deserialized parameter
 ++++++++++++++++++++++++++++++++
 

akka-http-tests/src/test/scala/akka/http/scaladsl/server/directives/ParameterDirectivesSpec.scala

@@ -7,6 +7,7 @@ package directives
 
 import org.scalatest.{ FreeSpec, Inside }
 import akka.http.scaladsl.unmarshalling.Unmarshaller.HexInt
+import akka.http.scaladsl.unmarshalling.Unmarshaller.CsvString
 
 class ParameterDirectivesSpec extends FreeSpec with GenericRoutingSpec with Inside {
   "when used with 'as[Int]' the parameter directive should" - {
@@ -52,6 +53,24 @@ class ParameterDirectivesSpec extends FreeSpec with GenericRoutingSpec with Insi
     }
   }
 
+  "when used with 'as(CsvString)' the parameter directive should" - {
+    val route =
+      parameter("names".as(CsvString)) { names ⇒
+        complete(s"The parameters are ${names.mkString(", ")}")
+      }
+
+    "extract a single name" in {
+      Get("/?names=Caplin") ~> route ~> check {
+        responseAs[String] shouldEqual "The parameters are Caplin"
+      }
+    }
+    "extract a number of names" in {
+      Get("/?names=Caplin,John") ~> route ~> check {
+        responseAs[String] shouldEqual "The parameters are Caplin, John"
+      }
+    }
+  }
+
   "when used with 'as(HexInt)' the parameter directive should" - {
     "extract parameter values as Int" in {
       Get("/?amount=1f") ~> {

akka-http/src/main/scala/akka/http/scaladsl/common/NameReceptacle.scala

@@ -7,8 +7,8 @@ package akka.http.scaladsl.common
 import akka.http.scaladsl.unmarshalling.{ FromStringUnmarshaller ⇒ FSU }
 
 private[http] trait ToNameReceptacleEnhancements {
-  implicit def symbol2NR(symbol: Symbol) = new NameReceptacle[String](symbol.name)
-  implicit def string2NR(string: String) = new NameReceptacle[String](string)
+  implicit def symbol2NR(symbol: Symbol): NameReceptacle[String] = new NameReceptacle[String](symbol.name)
+  implicit def string2NR(string: String): NameReceptacle[String] = new NameReceptacle[String](string)
 }
 object ToNameReceptacleEnhancements extends ToNameReceptacleEnhancements
 

akka-http/src/main/scala/akka/http/scaladsl/unmarshalling/PredefinedFromStringUnmarshallers.scala

@@ -4,6 +4,8 @@
 
 package akka.http.scaladsl.unmarshalling
 
+import scala.collection.immutable
+
 trait PredefinedFromStringUnmarshallers {
 
   implicit val byteFromStringUnmarshaller: Unmarshaller[String, Byte] =
@@ -76,6 +78,11 @@ trait PredefinedFromStringUnmarshallers {
       }
     }
 
+  val CsvString: Unmarshaller[String, immutable.Seq[String]] =
+    Unmarshaller.strict[String, immutable.Seq[String]] { string ⇒
+      string.split(",").toList
+    }
+
   private def numberFormatError(value: String, target: String): PartialFunction[Throwable, Nothing] = {
     case e: NumberFormatException ⇒
       throw if (value.isEmpty) Unmarshaller.NoContentException else new IllegalArgumentException(s"'$value' is not a valid $target value", e)