Share model across fe and be and add websocket support

5 files changed, 72 insertions, 11 deletions

diff --git a/build.sc b/build.sc
index 10354e9..3799ef2 100644
--- a/build.sc
+++ b/build.sc
@@ -1,11 +1,23 @@
 import mill._, scalalib._, scalajslib._
 
-object server extends ScalaModule {
-  def scalaVersion = "2.13.1"
+trait Shared extends ScalaModule {
+  def sharedSources = T.sources(build.millSourcePath / "shared")
+
+  def sources = T.sources(
+    super.sources() ++ sharedSources()
+  )
 
   def ivyDeps = Agg(
+    ivy"com.lihaoyi::scalatags::0.7.0", // html rendering DSL http://www.lihaoyi.com/scalatags/
+    ivy"com.lihaoyi::upickle::0.8.0" // json serializatio, is also included by cask http://www.lihaoyi.com/upickle/
+  )
+}
+
+object server extends ScalaModule with Shared {
+  def scalaVersion = "2.13.1"
+
+  def ivyDeps = super.ivyDeps() ++ Agg(
     ivy"com.lihaoyi::cask:0.3.6", // web framework, http://www.lihaoyi.com/cask/
-    ivy"com.lihaoyi::scalatags:0.7.0", // html rendering DSL http://www.lihaoyi.com/scalatags/
     ivy"io.getquill::quill-jdbc:3.4.10", // language integrated queries https://getquill.io/#docs
     ivy"org.xerial:sqlite-jdbc:3.28.0" // actual database driver, note the single ':'
   )
@@ -18,11 +30,11 @@ object server extends ScalaModule {
 
 }
 
-object webapp extends ScalaJSModule {
+object webapp extends ScalaJSModule with Shared {
   def scalaVersion = "2.13.1"
   def scalaJSVersion = "0.6.31" // https://www.scala-js.org/
 
-  def ivyDeps = Agg(
+  def ivyDeps = super.ivyDeps() ++ Agg(
     ivy"org.scala-js::scalajs-dom::0.9.7" // http://scala-js.github.io/scala-js-dom/
   )
 
diff --git a/server/src/Main.scala b/server/src/Main.scala
index 9d17fa4..0230d04 100644
--- a/server/src/Main.scala
+++ b/server/src/Main.scala
@@ -3,6 +3,8 @@ import io.getquill.{SnakeCase, SqliteJdbcContext}
 import scala.collection.mutable
 import com.typesafe.config.ConfigFactory
 import java.nio.file.Files
+import cask.endpoints.WsChannelActor
+import cask.util.Ws
 
 object Main extends cask.MainRoutes {
 
@@ -13,6 +15,8 @@ object Main extends cask.MainRoutes {
   ))
   import ctx._ // this import allows us to construct SQL queries in a nice DSL
 
+  object Templates extends Templates(scalatags.Text)
+
   // tables aren't typically create from within a program, but we do it here'
   // for demonstration purposes
   ctx.executeAction(
@@ -34,6 +38,30 @@ object Main extends cask.MainRoutes {
   @cask.postJson("/")
   def post(message: Message) = {
     run(query[Message].insert(lift(message)))
+    LiveMessages.broadcast(message)
+  }
+
+  object LiveMessages {
+    val channels = mutable.WeakHashMap.empty[WsChannelActor, Unit]
+
+    // This actor receives incoming messages from websockets. Since this
+    // example project is only interested in broadcasting, we ignore
+    // all messages received.
+    val incoming = cask.WsActor {
+      case _ =>
+    }
+
+    def broadcast(message: Message): Unit = channels.keySet.foreach(channel =>
+      channel.send(Ws.Text(upickle.default.write(message)))
+    )
+  }
+
+  @cask.websocket("/feed")
+  def messageFeed(): cask.WebsocketResult = {
+    cask.WsHandler{ channel =>
+      LiveMessages.channels += channel -> ()
+      LiveMessages.incoming
+    }
   }
 
   @cask.staticResources("/assets")
diff --git a/server/src/Message.scala b/shared/Message.scala
index 55b4602..55b4602 100644
--- a/server/src/Message.scala
+++ b/shared/Message.scala
diff --git a/server/src/Templates.scala b/shared/Templates.scala
index 3abb09e..9c3c292 100644
--- a/server/src/Templates.scala
+++ b/shared/Templates.scala
@@ -1,7 +1,7 @@
+import scalatags.generic.Bundle
 
-import scalatags.Text.all._
-
-object Templates {
+class Templates[Builder, Output <: FragT, FragT](val backend: Bundle[Builder, Output, FragT]) {
+  import backend.all._
 
   def message(msg: Message): Tag = {
     div(cls := "col-xs-12 col-sm-6 col-md-3 col-lg-2")(
@@ -59,7 +59,7 @@ object Templates {
         raw(
           """|document.addEventListener("DOMContentLoaded", function(event) {
              |  console.info("Starting ScalaJS application...")
-             |  Main.func() // run ScalaJS application
+             |  Main.main() // run ScalaJS application
              |})
              |""".stripMargin
         )
diff --git a/webapp/src/Main.scala b/webapp/src/Main.scala
index 5aa2f2b..7aa1322 100644
--- a/webapp/src/Main.scala
+++ b/webapp/src/Main.scala
@@ -5,9 +5,30 @@ import scalajs.js.annotation
 @annotation.JSExportTopLevel("Main")
 object Main {
 
+  object Templates extends Templates(scalatags.JsDom)
+
   @annotation.JSExport
-  def func() = {
-    dom.console.log("hello from ScalaJS!")
+  def main() = {
+
+    val container = dom.document.getElementById("conversation")
+    val address = {
+      val location = dom.window.location
+      val protocol = if (location.protocol == "https:") {
+        "wss"
+      } else {
+        "ws"
+      }
+      s"$protocol://${location.host}/feed"
+    }
+    val ws = new dom.WebSocket(address)
+
+    ws.onmessage = event => {
+      val msg = upickle.default.read[Message](
+        event.data.asInstanceOf[String])
+
+      container.appendChild(Templates.message(msg).render)
+      dom.window.scrollTo(0, dom.document.body.scrollHeight)
+    }
   }
 
 }