Implement trackStatic

build.mill

@@ -53,6 +53,9 @@ object scalive extends Module:
     def mvnDeps    = Seq(mvn"dev.zio::zio-http:3.4.0")
     def moduleDeps = Seq(core)
 
+    object test extends ScalaTests with scalalib.TestModule.ZioTest:
+      def zioTestVersion = "2.1.23"
+
 object example extends ScalaCommon:
   def moduleDeps = Seq(scalive.zio)
   def mvnDeps    = Seq(mvn"dev.optics::monocle-core:3.1.0", mvn"dev.zio::zio-logging:2.5.1")

scalive/core/src/scalive/LiveView.scala

@@ -3,8 +3,12 @@ package scalive
 import zio.*
 import zio.stream.*
 
+final case class LiveContext(staticChanged: Boolean)
+object LiveContext:
+  def staticChanged: URIO[LiveContext, Boolean] = ZIO.serviceWith[LiveContext](_.staticChanged)
+
 trait LiveView[Msg, Model]:
-  def init: Model | Task[Model]
+  def init: Model | RIO[LiveContext, Model]
-  def update(model: Model): Msg => Model | Task[Model]
+  def update(model: Model): Msg => Model | RIO[LiveContext, Model]
   def view(model: Dyn[Model]): HtmlElement
-  def subscriptions(model: Model): ZStream[Any, Nothing, Msg]
+  def subscriptions(model: Model): ZStream[LiveContext, Nothing, Msg]

scalive/core/src/scalive/StaticTracking.scala

@@ -0,0 +1,46 @@
+package scalive
+
+import scala.collection.mutable.ListBuffer
+
+import zio.json.*
+import zio.json.ast.Json
+
+object StaticTracking:
+  private val attrName     = phx.trackStatic.name
+  private val urlAttrNames = List(href.name, src.name)
+
+  def collect(el: HtmlElement): List[String] =
+    val urls = ListBuffer.empty[String]
+
+    def hasTrack(mods: Seq[Mod.Attr]): Boolean =
+      mods.exists {
+        case Mod.Attr.Static(`attrName`, _)                => true
+        case Mod.Attr.StaticValueAsPresence(`attrName`, v) => v
+        case Mod.Attr.DynValueAsPresence(`attrName`, dyn)  => dyn.currentValue
+        case _                                             => false
+      }
+
+    def loop(node: HtmlElement): Unit =
+      val attrs = node.attrMods
+      if hasTrack(attrs) then
+        attrs.foreach {
+          case Mod.Attr.Static(name, value) if urlAttrNames.contains(name) =>
+            urls += value
+          case Mod.Attr.Dyn(name, dyn, _) if urlAttrNames.contains(name) =>
+            urls += dyn.currentValue
+          case _ => ()
+        }
+      node.contentMods.foreach {
+        case Mod.Content.Tag(child) => loop(child)
+        case _                      => ()
+      }
+
+    loop(el)
+    urls.toList
+
+  def clientListFromParams(params: Option[Map[String, Json]]): Option[List[String]] =
+    params.flatMap(_.get("_track_static")).flatMap(_.as[List[String]].toOption)
+
+  def staticChanged(client: Option[List[String]], server: List[String]): Boolean =
+    client.exists(_ != server)
+end StaticTracking

scalive/core/test/src/scalive/StaticTrackingSpec.scala

@@ -0,0 +1,31 @@
+package scalive
+
+import utest.*
+import zio.json.ast.Json
+
+object StaticTrackingSpec extends TestSuite:
+  val tests = Tests {
+    test("collects href and src from tracked tags") {
+      val el = div(
+        scriptTag(phx.trackStatic := true, src  := "/static/app.js"),
+        linkTag(phx.trackStatic   := true, href := "/static/app.css"),
+        div()
+      )
+
+      val urls = StaticTracking.collect(el)
+      assert(urls == List("/static/app.js", "/static/app.css"))
+    }
+
+    test("extracts _track_static from params") {
+      val params = Map("_track_static" -> Json.Arr(Json.Str("/a.js"), Json.Str("/b.css")))
+      assert(StaticTracking.clientListFromParams(Some(params)) == Some(List("/a.js", "/b.css")))
+      assert(StaticTracking.clientListFromParams(None).isEmpty)
+    }
+
+    test("detects static changes when lists differ") {
+      val server = List("/a.js", "/b.css")
+      assert(!StaticTracking.staticChanged(Some(server), server))
+      assert(StaticTracking.staticChanged(Some(List("/a.js")), server))
+      assert(!StaticTracking.staticChanged(None, server))
+    }
+  }

scalive/zio/src/scalive/LiveRouter.scala

@@ -12,6 +12,7 @@ import zio.json.*
 import zio.stream.SubscriptionRef
 import zio.stream.ZStream
 
+import scalive.*
 import scalive.WebSocketMessage.Meta
 import scalive.WebSocketMessage.Payload
 
@@ -25,8 +26,9 @@ final case class LiveRoute[A, Msg, Model](
       val id: String =
         s"phx-${Base64.getUrlEncoder().withoutPadding().encodeToString(Random().nextBytes(12))}"
       val token = Token.sign("secret", id, "")
+      val ctx   = LiveContext(staticChanged = false)
       for
-        initModel <- normalize(lv.init)
+        initModel <- normalize(lv.init, ctx)
         el = lv.view(Var(initModel))
         _  = el.syncAll()
       yield Response.html(
@@ -57,6 +59,7 @@ class LiveChannel(private val sockets: SubscriptionRef[Map[String, Socket[?, ?]]
     id: String,
     token: String,
     lv: LiveView[Msg, Model],
+    ctx: LiveContext,
     meta: WebSocketMessage.Meta
   ): RIO[Scope, Unit] =
     sockets
@@ -65,11 +68,11 @@ class LiveChannel(private val sockets: SubscriptionRef[Map[String, Socket[?, ?]]
           case Some(socket) =>
             socket.shutdown *>
               Socket
-                .start(id, token, lv, meta)
+                .start(id, token, lv, ctx, meta)
                 .map(m.updated(id, _))
           case None =>
             Socket
-              .start(id, token, lv, meta)
+              .start(id, token, lv, ctx, meta)
               .map(m.updated(id, _))
       }.flatMap(_ => ZIO.logDebug(s"LiveView joined $id"))
 
@@ -101,6 +104,8 @@ object LiveChannel:
 
 class LiveRouter(rootLayout: HtmlElement => HtmlElement, liveRoutes: List[LiveRoute[?, ?, ?]]):
 
+  private val trackedStatic = StaticTracking.collect(rootLayout(div()))
+
   private val socketApp: WebSocketApp[Any] =
     Handler.webSocket { channel =>
       ZIO
@@ -154,7 +159,9 @@ class LiveRouter(rootLayout: HtmlElement => HtmlElement, liveRoutes: List[LiveRo
     : RIO[Scope, Option[WebSocketMessage]] =
     message.payload match
       case Payload.Heartbeat => ZIO.succeed(Some(message.okReply))
-      case Payload.Join(url, redirect, session, static, sticky) =>
+      case Payload.Join(url, redirect, session, static, params, sticky) =>
+        val clientStatics = static.orElse(StaticTracking.clientListFromParams(params))
+        val ctx           = LiveContext(StaticTracking.staticChanged(clientStatics, trackedStatic))
         ZIO
           .fromEither(URL.decode(url.orElse(redirect).getOrElse(???))).flatMap(url =>
             val req = Request(url = url)
@@ -164,9 +171,9 @@ class LiveRouter(rootLayout: HtmlElement => HtmlElement, liveRoutes: List[LiveRo
                   .decode(req.path)
                   .toOption
                   .map(route.liveviewBuilder(_, req))
-                  .map(
+                  .map(lv =>
                     ZIO.logDebug(s"Joining LiveView ${route.path.toString} ${message.topic}") *>
-                      liveChannel.join(message.topic, session, _, message.meta)
+                      liveChannel.join(message.topic, session, lv, ctx, message.meta)
                   )
               )
               .collectFirst { case Some(join) => join.map(_ => None) }

scalive/zio/src/scalive/Socket.scala

@@ -20,6 +20,7 @@ object Socket:
     id: String,
     token: String,
     lv: LiveView[Msg, Model],
+    ctx: LiveContext,
     meta: WebSocketMessage.Meta
   ): RIO[Scope, Socket[Msg, Model]] =
     ZIO.logAnnotate("lv", id) {
@@ -27,14 +28,15 @@ object Socket:
         inbox  <- Queue.bounded[(Payload.Event, WebSocketMessage.Meta)](4)
         outHub <- Hub.unbounded[(Payload, WebSocketMessage.Meta)]
 
-        initModel <- normalize(lv.init)
+        initModel <- normalize(lv.init, ctx)
         modelVar = Var(initModel)
         el       = lv.view(modelVar)
         ref <- Ref.make((modelVar, el))
 
         initDiff = el.diff(trackUpdates = false)
 
-        lvStreamRef <- SubscriptionRef.make(lv.subscriptions(initModel))
+        lvStreamRef <-
+          SubscriptionRef.make(lv.subscriptions(initModel).provideLayer(ZLayer.succeed(ctx)))
 
         clientMsgStream = ZStream.fromQueue(inbox)
         serverMsgStream = (ZStream.fromZIO(lvStreamRef.get) ++ lvStreamRef.changes)
@@ -53,9 +55,11 @@ object Socket:
                                  )
                                )
                            updatedModel <-
-                             normalize(lv.update(modelVar.currentValue)(f(event.params)))
+                             normalize(lv.update(modelVar.currentValue)(f(event.params)), ctx)
                            _ = modelVar.set(updatedModel)
-                           _ <- lvStreamRef.set(lv.subscriptions(updatedModel))
+                           _ <- lvStreamRef.set(
+                                  lv.subscriptions(updatedModel).provideLayer(ZLayer.succeed(ctx))
+                                )
                            diff    = el.diff()
                            payload = Payload.okReply(LiveResponse.Diff(diff))
                            _ <- outHub.publish(payload -> meta)
@@ -64,7 +68,7 @@ object Socket:
         serverFiber <- serverMsgStream.runForeach { (msg, meta) =>
                          for
                            (modelVar, el) <- ref.get
-                           updatedModel   <- normalize(lv.update(modelVar.currentValue)(msg))
+                           updatedModel   <- normalize(lv.update(modelVar.currentValue)(msg), ctx)
                            _       = modelVar.set(updatedModel)
                            diff    = el.diff()
                            payload = Payload.Diff(diff)

scalive/zio/src/scalive/WebSocketMessage.scala

@@ -82,7 +82,8 @@ object WebSocketMessage:
       redirect: Option[String],
       // params: Map[String, String],
       session: String,
-      static: Option[String],
+      static: Option[List[String]],
+      params: Option[Map[String, Json]],
       sticky: Boolean)
     case Leave
     case Close

scalive/zio/src/scalive/ZIOHelpers.scala

@@ -2,7 +2,7 @@ package scalive
 
 import zio.*
 
-private def normalize[A](value: A | Task[A]): Task[A] =
+private def normalize[A](value: A | RIO[LiveContext, A], ctx: LiveContext): Task[A] =
   value match
-    case t: Task[?] @unchecked => t.asInstanceOf[Task[A]]
+    case t: ZIO[LiveContext, Throwable, A] @unchecked => t.provide(ZLayer.succeed(ctx))
     case v                                            => ZIO.succeed(v.asInstanceOf[A])

scalive/zio/test/src/scalive/SocketSpec.scala

@@ -0,0 +1,76 @@
+package scalive
+
+import zio.*
+import zio.stream.ZStream
+import zio.test.*
+
+import scalive.WebSocketMessage.LiveResponse
+import scalive.WebSocketMessage.Payload
+
+object SocketSpec extends ZIOSpecDefault:
+
+  enum Msg:
+    case FromClient
+    case FromServer
+
+  final case class Model(counter: Int = 0, staticFlag: Option[Boolean] = None)
+
+  private val meta = WebSocketMessage.Meta(None, None, topic = "t", eventType = "event")
+
+  private def makeLiveView(serverStream: ZStream[LiveContext, Nothing, Msg]) =
+    new LiveView[Msg, Model]:
+      def init: Model | RIO[LiveContext, Model] =
+        LiveContext.staticChanged.map(flag => Model(staticFlag = Some(flag)))
+
+      def update(model: Model): Msg => Model | RIO[LiveContext, Model] = {
+        case Msg.FromClient => ZIO.succeed(model.copy(counter = model.counter + 1))
+        case Msg.FromServer => ZIO.succeed(model.copy(counter = model.counter + 10))
+      }
+
+      def view(model: Dyn[Model]): HtmlElement =
+        div(
+          idAttr := "root",
+          phx.onClick(Msg.FromClient),
+          model(_.counter.toString)
+        )
+
+      def subscriptions(model: Model): ZStream[LiveContext, Nothing, Msg] = serverStream
+
+  private def makeSocket(ctx: LiveContext, lv: LiveView[Msg, Model]) =
+    Socket.start("id", "token", lv, ctx, meta)
+
+  override def spec = suite("SocketSpec")(
+    test("emits init diff and uses LiveContext") {
+      val ctx = LiveContext(staticChanged = true)
+      val lv  = makeLiveView(ZStream.empty)
+      for
+        socket <- makeSocket(ctx, lv)
+        msgs   <- socket.outbox.take(1).runHead
+      yield assertTrue(
+        msgs.size == 1,
+        msgs.head._1 match
+          case Payload.Reply("ok", LiveResponse.InitDiff(_)) => true
+          case _                                             => false
+        ,
+        msgs.head._2 == meta
+      )
+    },
+    test("server stream emits diff") {
+      val ctx = LiveContext(staticChanged = false)
+      val lv  = makeLiveView(ZStream.succeed(Msg.FromServer))
+      for
+        socket <- makeSocket(ctx, lv)
+        diff   <- socket.outbox.drop(1).runHead.some
+      yield assertTrue(diff._1.isInstanceOf[Payload.Diff])
+    },
+    test("shutdown stops outbox") {
+      val ctx = LiveContext(staticChanged = false)
+      val lv  = makeLiveView(ZStream.empty)
+      for
+        socket <- makeSocket(ctx, lv)
+        _      <- socket.shutdown
+        res    <- socket.outbox.runCollect
+      yield assertTrue(res.nonEmpty)
+    }
+  )
+end SocketSpec