Typing a Rest Action

geelen · Jan 21, 2010 · 5085839 · 5085839
1 parent 5c86fbe
commit 5085839
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Showing 5 changed files with 27 additions and 13 deletions.
diff --git a/src/main/scala/rest/rest.scala b/src/main/scala/rest/rest.scala
@@ -1,4 +1,6 @@
 import rest.Resourced
+import scalaz._
+import Scalaz._
 
 package object rest {
   implicit def showMe[T](t: T)(implicit r: Resourced[T]) = new {
@@ -8,22 +10,34 @@ package object rest {
       def edit = r.edit(t)
     }
   }
+
+  implicit val restFunctor = new Functor[rest.Action] {
+    def fmap[A,B](a: Action[A], f: A => B): Action[B] = a match {
+      case Index => Index
+      case Create => Create
+      case Show(v) => Show(f(v))
+      case Update(v) => Update(f(v))
+      case Destroy(v) => Destroy(f(v))
+      case New => New
+      case Edit(v) => Edit(f(v))
+    }
+  }
 }
 
 package rest {
 
-sealed trait Action
+sealed trait Action[+T]
 
 // Ze actions.
-case object Index extends Action
-case object Create extends Action
-case class Show(id: String) extends Action
-case class Update(id: String) extends Action
-case class Destroy(id: String) extends Action
+case object Index extends Action[Nothing]
+case object Create extends Action[Nothing]
+case class Show[T](id: T) extends Action[T]
+case class Update[T](id: T) extends Action[T]
+case class Destroy[T](id: T) extends Action[T]
 
 // Ze actions for form requests
-case object New extends Action
-case class Edit(id: String) extends Action
+case object New extends Action[Nothing]
+case class Edit[T](id: T) extends Action[T]
 
 // Represents resource root, and action
 // eg. Base("breweries", Index) could represent GET /breweries
@@ -34,7 +48,7 @@ case class Edit(id: String) extends Action
 case class Context(resource: String, id: String)
 
 // A full request: any number of parent contexts and a final action
-case class RestRequest(contexts: List[Context], resource: String, base: Action, contentType: Option[String])
+case class RestRequest[T](contexts: List[Context], resource: String, base: Action[T], contentType: Option[String])
 
 case class Resource(name: String) {
   def show(id: String) = "/" + name + "/" + id

diff --git a/src/main/scala/scapps/RichRequest.scala b/src/main/scala/scapps/RichRequest.scala
@@ -14,7 +14,7 @@ trait RichRequest[IN[_]] {
 
   def update[T](t: T)(implicit postable: RequestUpdate[T], fl: FoldLeft[IN]) = postable.update(request)(t)
 
-  lazy val action: Option[(String, Action)] = {
+  lazy val action: Option[(String, Action[String])] = {
     request match {
       case MethodParts(GET, List(base)) => Some((base, rest.Index))
       case MethodParts(GET, List(base, "new")) => Some((base, New))

diff --git a/src/main/scala/wd/controllers/BeersController.scala b/src/main/scala/wd/controllers/BeersController.scala
@@ -15,7 +15,7 @@ import com.google.appengine.api.datastore.DatastoreService
 
 class BeersController(val ds: DatastoreService)(implicit val request: Request[Stream]) extends Controller with ControllerHelpers {
 
-  def handle(v: Action) = v match {
+  def handle(v: Action[String]) = v match {
     case New => Some {
       val breweryId = request("breweryKey")
       breweryId ∘ { id =>

diff --git a/src/main/scala/wd/controllers/BreweriesController.scala b/src/main/scala/wd/controllers/BreweriesController.scala
@@ -21,7 +21,7 @@ class BreweriesController(val ds: DatastoreService)(implicit val request: Reques
 
   def find(keyName: String) = Brewery.findById(keyName)(ds)
 
-  def handle(v: Action): Option[Response[Stream]] = v match {
+  def handle(v: Action[String]): Option[Response[Stream]] = v match {
     case New => render(breweries.nnew) η
 
     case rest.Show(keyName) => {

diff --git a/src/main/scala/wd/controllers/Home.scala b/src/main/scala/wd/controllers/Home.scala
@@ -40,7 +40,7 @@ final class WorthDrinkingServlet extends ServletApplicationServlet[Stream, Strea
     userService.createLoginURL("/")
   })(r)).kleisli[Option]
 
-  def resource(base: String, f: (Request[Stream] => Action => Option[Response[Stream]])) = ☆((r: Request[Stream]) => {
+  def resource(base: String, f: (Request[Stream] => Action[String] => Option[Response[Stream]])) = ☆((r: Request[Stream]) => {
     r.action match {
       case Some((b, action)) if b == base => f(r)(action)
       case _ => none