scala · sjrd · Oct 1, 2024 · Aug 12, 2024 · Aug 26, 2024 · Aug 26, 2024
diff --git a/_includes/_markdown/install-cask.md b/_includes/_markdown/install-cask.md
@@ -0,0 +1,37 @@
+{% altDetails require-info-box 'Getting Cask' %}
+
+{% tabs cask-install class=tabs-build-tool %}
+
+{% tab 'Scala CLI' %}
+You can declare a dependency on Cask with the following `using` directive:
+```scala
+//> using dep "com.lihaoyi::cask::0.9.2"
+```
+{% endtab %}
+
+{% tab 'sbt' %}
+In your `build.sbt`, you can add a dependency on Cask:
+```scala
+lazy val example = project.in(file("example"))
+  .settings(
+    scalaVersion := "3.4.2",
+    libraryDependencies += "com.lihaoyi" %% "cask" % "0.9.2",
+    fork := true
+  )
+```
+{% endtab %}
+
+{% tab 'Mill' %}
+In your `build.sc`, you can add a dependency on Cask:
+```scala
+object example extends RootModule with ScalaModule {
+  def scalaVersion = "3.3.3"
+  def ivyDeps = Agg(
+    ivy"com.lihaoyi::cask::0.9.2"
+  )
+}
+```
+{% endtab %}
+
+{% endtabs %}
+{% endaltDetails %}
diff --git a/_overviews/toolkit/OrderedListOfMdFiles b/_overviews/toolkit/OrderedListOfMdFiles
@@ -27,3 +27,10 @@ http-client-request-body.md
 http-client-json.md
 http-client-upload-file.md
 http-client-what-else.md
+web-server-intro.md
+web-server-static.md
+web-server-dynamic.md
+web-server-query-parameters.md
+web-server-input.md
+web-server-websockets.md
+web-server-cookies-and-decorators.md
diff --git a/_overviews/toolkit/http-client-what-else.md b/_overviews/toolkit/http-client-what-else.md
@@ -4,7 +4,7 @@ type: section
 description: An incomplete list of features of sttp
 num: 29
 previous-page: http-client-upload-file
-next-page: 
+next-page: web-server-intro
 ---
 
 {% include markdown.html path="_markdown/install-upickle.md" %}

diff --git a/_overviews/toolkit/introduction.md b/_overviews/toolkit/introduction.md
@@ -22,6 +22,10 @@ toolkit-index:
     description: Sending HTTP requests and uploading files with sttp.
     icon: "fa fa-globe"
     link: /toolkit/http-client-intro.html
+  - title: Web servers
+    description: Building web servers with Cask.
+    icon: "fa fa-server"
+    link: /toolkit/web-server-intro.html
 ---
 
 ## What is the Scala Toolkit?

diff --git a/_overviews/toolkit/web-server-cookies-and-decorators.md b/_overviews/toolkit/web-server-cookies-and-decorators.md
@@ -0,0 +1,188 @@
+---
+title: How to use cookies and decorators?
+type: section
+description: Using cookies and decorators with Cask
+num: 36
+previous-page: web-server-websockets
+next-page: 
+---
+
+{% include markdown.html path="_markdown/install-cask.md" %}
+
+## Using cookies
+
+Cookies are saved by adding them to the `cookies` parameter of the `cask.Response` constructor. 
+
+In this example, we are building a rudimentary authentication service. The `getLogin` method provides a form where
+the user can enter their username and password. The `postLogin` method reads the credentials. If they match the expected ones, it generates a session
+identifier is generated, saves it in the application state, and sends back a cookie with the identifier.
+
+Cookies can be read either with a method parameter of `cask.Cookie` type or by accessing the `cask.Request` directly.
+If using the former method, the names of parameters have to match the names of cookies. If a cookie with a matching name is not
+found, an error response will be returned. In the `checkLogin` function, the former method is used, as the cookie is not
+present before the user logs in.
+
+To delete a cookie, set its `expires` parameter to an instant in the past, for example `Instant.EPOCH`. 
+
+{% tabs web-server-cookies-1 class=tabs-scala-version %}
+{% tab 'Scala 2' %}
+
+```scala
+import java.util.UUID
+import java.util.concurrent.ConcurrentHashMap
+
+object Example extends cask.MainRoutes {
+
+  val sessionIds = ConcurrentHashMap.newKeySet[String]()
+
+  @cask.get("/login")
+  def getLogin(): cask.Response[String] = {
+    val html =
+      """<!doctype html>
+        |<html>
+        |<body>
+        |<form action="/login" method="post">
+        |  <label for="name">Username:</label><br>
+        |  <input type="text" name="name" value=""><br>
+        |  <label for="password">Password:</label><br>
+        |  <input type="text" name="password" value=""><br><br>
+        |  <input type="submit" value="Submit">
+        |</form>
+        |</body>
+        |</html>""".stripMargin
+
+    cask.Response(data = html, headers = Seq("Content-Type" -> "text/html"))
+  }
+
+  @cask.postForm("/login")
+  def postLogin(name: String, password: String): cask.Response[String] = {
+    if (name == "user" && password == "password") {
+      val sessionId = UUID.randomUUID().toString
+      sessionIds.add(sessionId)
+      cask.Response(data = "Success!", cookies = Seq(cask.Cookie("sessionId", sessionId)))
+    } else {
+      cask.Response(data = "Authentication failed", statusCode = 401)
+    }
+  }
+
+  @cask.get("/check")
+  def checkLogin(request: cask.Request): String = {
+    val sessionId = request.cookies.get("sessionId")
+    if (sessionId.exists(cookie => sessionIds.contains(cookie.value))) {
+      "You are logged in"
+    } else {
+      "You are not logged in"
+    }
+  }
+
+  @cask.get("/logout")
+  def logout(sessionId: cask.Cookie) = {
+    sessionIds.remove(sessionId.value)
+    cask.Response(data = "Successfully logged out!", cookies = Seq(cask.Cookie("sessionId", "", expires = Instant.EPOCH)))
+  }
+
+  initialize()
+}
+```
+{% endtab %}
+{% tab 'Scala 3' %}
+```scala
+import java.util.UUID
+import java.util.concurrent.ConcurrentHashMap
+
+object Example extends cask.MainRoutes:
+
+  val sessionIds = ConcurrentHashMap.newKeySet[String]()
+
+  @cask.get("/login")
+  def getLogin(): cask.Response[String] =
+    val html =
+      """<!doctype html>
+        |<html>
+        |<body>
+        |<form action="/login" method="post">
+        |  <label for="name">Username:</label><br>
+        |  <input type="text" name="name" value=""><br>
+        |  <label for="password">Password:</label><br>
+        |  <input type="text" name="password" value=""><br><br>
+        |  <input type="submit" value="Submit">
+        |</form>
+        |</body>
+        |</html>""".stripMargin
+
+    cask.Response(data = html, headers = Seq("Content-Type" -> "text/html"))
+
+  @cask.postForm("/login")
+  def postLogin(name: String, password: String): cask.Response[String] =
+    if name == "user" && password == "password" then
+        val sessionId = UUID.randomUUID().toString
+        sessionIds.add(sessionId)
+        cask.Response(data = "Success!", cookies = Seq(cask.Cookie("sessionId", sessionId)))
+    else
+      cask.Response(data = "Authentication failed", statusCode = 401)
+
+  @cask.get("/check")
+  def checkLogin(request: cask.Request): String =
+    val sessionId = request.cookies.get("sessionId")
+    if sessionId.exists(cookie => sessionIds.contains(cookie.value)) then
+      "You are logged in"
+    else
+      "You are not logged in"
+
+  @cask.get("/logout")
+  def logout(sessionId: cask.Cookie): cask.Response[String] = 
+    sessionIds.remove(sessionId.value)
+    cask.Response(data = "Successfully logged out!", cookies = Seq(cask.Cookie("sessionId", "", expires = Instant.EPOCH)))
+
+  initialize()
+```
+{% endtab %}
+{% endtabs %}
+
+## Using decorators
+
+Decorators can be used for extending endpoints functionality with validation or new parameters. They are defined by extending
+`cask.RawDecorator` class. They are used as annotations.
+
+In this example, the `loggedIn` decorator is used to check if the user is logged in before accessing the `/decorated`
+endpoint.
+
+The decorator class can pass additional arguments to the decorated endpoint using a map. The passed arguments are available
+through the last argument group. Here we are passing the session identifier to an argument named `sessionId`.
+
+{% tabs web-server-cookies-2 class=tabs-scala-version %}
+{% tab 'Scala 2' %}
+```scala
+class loggedIn extends cask.RawDecorator {
+  override def wrapFunction(ctx: cask.Request, delegate: Delegate): Result[Raw] = {
+    ctx.cookies.get("sessionId") match {
+      case Some(cookie) if sessionIds.contains(cookie.value) => delegate(Map("sessionId" -> cookie.value))
+      case _ => cask.router.Result.Success(cask.model.Response("You aren't logged in", 403))
+    }
+  }
+}
+
+@loggedIn()
+@cask.get("/decorated")
+def decorated()(sessionId: String): String = {
+  s"You are logged in with id: $sessionId"
+}
+```
+{% endtab %}
+{% tab 'Scala 3' %}
+```scala
+class loggedIn extends cask.RawDecorator:
+  override def wrapFunction(ctx: cask.Request, delegate: Delegate): Result[Raw] =
+    ctx.cookies.get("sessionId") match
+      case Some(cookie) if sessionIds.contains(cookie.value) =>
+        delegate(Map("sessionId" -> cookie.value))
+      case _ =>
+        cask.router.Result.Success(cask.model.Response("You aren't logged in", 403))
+
+
+@loggedIn()
+@cask.get("/decorated")
+def decorated()(sessionId: String): String = s"You are logged in with id: $sessionId"
+```
+{% endtab %}
+{% endtabs %}