TodoMVC kotlin ktor (#3651)

Part of #3611 --------- Co-authored-by: Li Haoyi <haoyi.sg@gmail.com>
com-lihaoyi · Oct 5, 2024 · d0cc6f8 · d0cc6f8
1 parent d43417e
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diff --git a/example/kotlinlib/web/1-hello-ktor/build.mill b/example/kotlinlib/web/1-hello-ktor/build.mill
@@ -30,7 +30,7 @@ object `package` extends RootModule with KotlinModule {
 
 > mill runBackground
 
-> curl http://localhost:8080
+> curl http://localhost:8090
 ...<h1>Hello, World!</h1>...
 
 > mill clean runBackground

diff --git a/example/kotlinlib/web/1-hello-ktor/src/com/example/HelloKtor.kt b/example/kotlinlib/web/1-hello-ktor/src/com/example/HelloKtor.kt
@@ -7,7 +7,7 @@ import io.ktor.server.response.*
 import io.ktor.server.routing.*
 
 fun main() {
- embeddedServer(Netty, port = 8080, host = "0.0.0.0", module = Application::module)
+ embeddedServer(Netty, port = 8090, host = "0.0.0.0", module = Application::module)
  .start(wait = true)
 }
 

diff --git a/example/kotlinlib/web/2-todo-ktor/build.mill b/example/kotlinlib/web/2-todo-ktor/build.mill
@@ -0,0 +1,58 @@
+//// SNIPPET:BUILD
+package build
+import mill._, kotlinlib._
+
+object `package` extends RootModule with KotlinModule {
+
+ def kotlinVersion = "1.9.24"
+
+ def mainClass = Some("com.example.TodoMVCApplicationKt")
+
+ val ktorVersion = "2.3.12"
+ val exposedVersion = "0.53.0"
+
+ def ivyDeps = Agg(
+ ivy"io.ktor:ktor-server-core-jvm:$ktorVersion",
+ ivy"io.ktor:ktor-server-netty-jvm:$ktorVersion",
+ ivy"org.jetbrains.exposed:exposed-core:$exposedVersion",
+ ivy"org.jetbrains.exposed:exposed-jdbc:$exposedVersion",
+ ivy"com.h2database:h2:2.2.224",
+ ivy"io.ktor:ktor-server-webjars-jvm:$ktorVersion",
+ ivy"org.webjars:jquery:3.2.1",
+ ivy"io.ktor:ktor-server-thymeleaf-jvm:$ktorVersion",
+ ivy"org.webjars:webjars-locator:0.41",
+ ivy"org.webjars.npm:todomvc-common:1.0.5",
+ ivy"org.webjars.npm:todomvc-app-css:2.4.1",
+ ivy"ch.qos.logback:logback-classic:1.4.14"
+ )
+
+ object test extends KotlinTests with TestModule.Junit5 {
+ def ivyDeps = super.ivyDeps() ++ Agg(
+ ivy"io.kotest:kotest-runner-junit5-jvm:5.9.1",
+ ivy"io.ktor:ktor-server-test-host-jvm:2.3.12"
+ )
+ }
+}
+
+
+// This example implementing the well known
+// https://todomvc.com/[TodoMVC] example app using Kotlin and Ktor. Apart from running a webserver,
+// this example also demonstrates:
+
+// * Serving HTML templates using Thymeleaf
+// * Serving static Javascript and CSS using Webjars
+// * Querying a SQL database using Exposed
+// * Testing using a H2 in-memory database
+
+/** Usage
+
+> mill test
+
+> mill runBackground
+
+> curl http://localhost:8091
+...<h1>todos</h1>...
+
+> mill clean runBackground
+
+*/
diff --git a/example/kotlinlib/web/2-todo-ktor/resources/logback.xml b/example/kotlinlib/web/2-todo-ktor/resources/logback.xml
@@ -0,0 +1,12 @@
+<configuration>
+ <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
+ <encoder>
+ <pattern>%d{YYYY-MM-dd HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n</pattern>
+ </encoder>
+ </appender>
+ <root level="trace">
+ <appender-ref ref="STDOUT"/>
+ </root>
+ <logger name="org.eclipse.jetty" level="INFO"/>
+ <logger name="io.netty" level="INFO"/>
+</configuration>
diff --git a/example/kotlinlib/web/2-todo-ktor/resources/templates/thymeleaf/fragments.html b/example/kotlinlib/web/2-todo-ktor/resources/templates/thymeleaf/fragments.html
@@ -0,0 +1,16 @@
+<html xmlns="http://www.w3.org/1999/xhtml" xmlns:th="http://www.thymeleaf.org" lang="en">
+<li th:fragment="todoItem(item)" th:classappend="${item.completed?'completed':''}">
+ <div class="view">
+ <form method="post" th:action="@{~/{id}/toggle(id=${item.id})}">
+ <input class="toggle" type="checkbox"
+ onchange="this.form.submit()"
+ th:attrappend="checked=${item.completed?'true':null}">
+ <label th:text="${item.title}">Taste JavaScript</label>
+ </form>
+ <form method="post" th:action="@{~/{id}/delete(id=${item.id})}">
+ <button class="destroy"></button>
+ </form>
+ </div>
+ <input class="edit" value="Create a TodoMVC template">
+</li>
+</html>
diff --git a/example/kotlinlib/web/2-todo-ktor/resources/templates/thymeleaf/index.html b/example/kotlinlib/web/2-todo-ktor/resources/templates/thymeleaf/index.html
@@ -0,0 +1,84 @@
+<!doctype html>
+<html xmlns="http://www.w3.org/1999/xhtml"
+ xmlns:th="http://www.thymeleaf.org"
+ lang="en">
+<head>
+ <meta charset="utf-8">
+ <meta name="viewport" content="width=device-width, initial-scale=1">
+ <title>Template • TodoMVC</title>
+ <link rel="stylesheet" th:href="@{~/webjars/todomvc-common/base.css}">
+ <link rel="stylesheet" th:href="@{~/webjars/todomvc-app-css/index.css}">
+</head>
+<body>
+<section class="todoapp">
+ <header class="header">
+ <h1>todos</h1>
+ <p></p>
+ <form th:action="@{~/save}" method="post" th:object="${item}">
+ <input class="new-todo" placeholder="What needs to be done?" autofocus
+ id="item" name="title">
+ </form>
+ </header>
+ <!-- This section should be hidden by default and shown when there are todos -->
+ <section class="main" th:if="${totalItemCount > 0}">
+ <form method="post" th:action="@{~/toggle-all}">
+ <input id="toggle-all" class="toggle-all" type="checkbox"
+ onclick="this.form.submit()">
+ <label for="toggle-all">Mark all as complete</label>
+ </form>
+ <ul class="todo-list" th:remove="all-but-first">
+ <li th:insert="fragments :: todoItem(${item})" th:each="item : ${todoItems}" th:remove="tag">
+ </li>
+ <!-- These are here just to show the structure of the list items -->
+ <!-- List items should get the class `editing` when editing and `completed` when marked as completed -->
+ <li class="completed">
+ <div class="view">
+ <input class="toggle" type="checkbox" checked>
+ <label>Taste JavaScript</label>
+ <button class="destroy"></button>
+ </div>
+ <input class="edit" value="Create a TodoMVC template">
+ </li>
+ <li>
+ <div class="view">
+ <input class="toggle" type="checkbox">
+ <label>Buy a unicorn</label>
+ <button class="destroy"></button>
+ </div>
+ <input class="edit" value="Rule the web">
+ </li>
+ </ul>
+ </section>
+ <!-- This footer should be hidden by default and shown when there are todos -->
+ <footer class="footer" th:if="${totalItemCount > 0}">
+ <th:block th:unless="${activeItemCount == 1}">
+ <span class="todo-count"><strong th:text="${activeItemCount}">0</strong> items left</span>
+ </th:block>
+ <th:block th:if="${activeItemCount == 1}">
+ <span class="todo-count"><strong>1</strong> item left</span>
+ </th:block>
+ <ul class="filters">
+ <li>
+ <a th:href="@{~/}"
+ th:classappend="${todoFilter == 'ALL'?'selected':''}">All</a>
+ </li>
+ <li>
+ <a th:href="@{~/active}"
+ th:classappend="${todoFilter == 'ACTIVE'?'selected':''}">Active</a>
+ </li>
+ <li>
+ <a th:href="@{~/completed}"
+ th:classappend="${todoFilter == 'COMPLETED'?'selected':''}">Completed</a>
+ </li>
+ </ul>
+ <form th:action="@{~/completed/delete}"
+ th:if="${numberOfCompletedItems > 0}">
+ <button class="clear-completed">Clear completed</button>
+ </form>
+ </footer>
+</section>
+<footer class="info">
+ <p>Double-click to edit a todo</p>
+</footer>
+</body>
+</html>
diff --git a/example/kotlinlib/web/2-todo-ktor/src/com/example/TodoItem.kt b/example/kotlinlib/web/2-todo-ktor/src/com/example/TodoItem.kt
@@ -0,0 +1,6 @@
+package com.example
+
+import java.util.UUID
+
+data class TodoItem(val id: UUID , val title: String, val completed: Boolean = false)
+
diff --git a/example/kotlinlib/web/2-todo-ktor/src/com/example/TodoItemController.kt b/example/kotlinlib/web/2-todo-ktor/src/com/example/TodoItemController.kt
@@ -0,0 +1,83 @@
+package com.example
+
+import io.ktor.server.application.*
+import io.ktor.server.request.*
+import io.ktor.server.response.*
+import io.ktor.server.routing.*
+import io.ktor.server.thymeleaf.*
+import io.ktor.server.util.*
+import java.util.*
+
+enum class ListFilter {
+ ALL,
+ ACTIVE,
+ COMPLETED
+}
+
+data class TodoItemFormData(var title: String? = null)
+
+fun modelContent(
+ todos: List<TodoItem>,
+ filter: ListFilter
+): Map<String, Any> {
+ val activeItemCount = todos.count { !it.completed }
+ val numberOfCompletedItems = todos.count { it.completed }
+
+ val items = when (filter) {
+ ListFilter.ALL -> todos
+ ListFilter.ACTIVE -> todos.filterNot { it.completed }
+ ListFilter.COMPLETED -> todos.filter { it.completed }
+ }
+
+ return mapOf(
+ "item" to TodoItemFormData(),
+ "todoItems" to items,
+ "totalItemCount" to todos.size,
+ "activeItemCount" to activeItemCount,
+ "numberOfCompletedItems" to numberOfCompletedItems,
+ "filter" to filter.name
+ )
+}
+
+fun Application.configureRoutes(repository: TodoItemRepository) {
+ routing {
+ get("/") {
+ val todos = repository.findAll()
+ call.respond(ThymeleafContent("index", modelContent(todos, ListFilter.ALL)))
+ }
+ get("/active") {
+ val todos = repository.findAll()
+ call.respond(ThymeleafContent("index", modelContent(todos, ListFilter.ACTIVE)))
+ }
+ get("/completed") {
+ val todos = repository.findAll()
+ call.respond(ThymeleafContent("index", modelContent(todos, ListFilter.COMPLETED)))
+ }
+ get("/completed/delete") {
+ repository.findAll().filter { it.completed }
+ .forEach { repository.deleteById(it.id) }
+ call.respondRedirect("/")
+ }
+ post("/save") {
+ val title = call.receiveParameters().getOrFail("title")
+ repository.save(TodoItem(UUID.randomUUID(), title))
+ call.respondRedirect("/")
+ }
+ post("/{id}/delete") {
+ val id = call.parameters.getOrFail("id")
+ repository.deleteById(UUID.fromString(id))
+ call.respondRedirect("/")
+ }
+ post("/{id}/toggle") {
+ val id = call.parameters.getOrFail("id")
+ val item = repository.findById(UUID.fromString(id))
+ repository.save(item.copy(completed = !item.completed))
+ call.respondRedirect("/")
+ }
+ post("/toggle-all") {
+ repository.findAll().map { it.copy(completed = !it.completed) }
+ .forEach { repository.save(it) }
+ call.respondRedirect("/")
+ }
+ }
+}
diff --git a/example/kotlinlib/web/2-todo-ktor/src/com/example/TodoItemRepository.kt b/example/kotlinlib/web/2-todo-ktor/src/com/example/TodoItemRepository.kt
@@ -0,0 +1,62 @@
+package com.example
+
+import kotlinx.coroutines.Dispatchers
+import org.jetbrains.exposed.sql.*
+import org.jetbrains.exposed.sql.SqlExpressionBuilder.eq
+import org.jetbrains.exposed.sql.transactions.experimental.newSuspendedTransaction
+import org.jetbrains.exposed.sql.transactions.transaction
+import java.util.UUID
+
+interface TodoItemRepository {
+ suspend fun save(item: TodoItem)
+ suspend fun findById(id: UUID): TodoItem
+ suspend fun findAll(): List<TodoItem>
+ suspend fun deleteById(id: UUID)
+}
+
+class TodoItemNotFound(id: String) : Exception("TodoItem $id not found")
+
+class TodoItemRepositoryImpl(database: Database) : TodoItemRepository {
+
+ object TodoItems : Table() {
+ val id = uuid("id")
+ val title = varchar("title", length = 50)
+ val completed = bool("completed")
+
+ override val primaryKey = PrimaryKey(id)
+ }
+
+ init {
+ transaction(database) {
+ SchemaUtils.create(TodoItems)
+ }
+ }
+
+ override suspend fun save(item: TodoItem): Unit = query {
+ TodoItems.upsert {
+ it[id] = item.id
+ it[title] = item.title
+ it[completed] = item.completed
+ }
+ }
+
+ override suspend fun findById(id: UUID): TodoItem = query {
+ TodoItems.selectAll().where(TodoItems.id eq id)
+ .map { TodoItem(it[TodoItems.id], it[TodoItems.title], it[TodoItems.completed]) }
+ .singleOrNull() ?: throw TodoItemNotFound(id.toString())
+ }
+
+
+ override suspend fun findAll(): List<TodoItem> = query {
+ TodoItems.selectAll()
+ .map { TodoItem(it[TodoItems.id], it[TodoItems.title], it[TodoItems.completed]) }
+ }
+
+
+ override suspend fun deleteById(id: UUID): Unit = query {
+ TodoItems.deleteWhere { TodoItems.id eq id }
+ }
+
+ private suspend fun <T> query(block: suspend () -> T): T =
+ newSuspendedTransaction(Dispatchers.IO) { block() }
+}
diff --git a/example/kotlinlib/web/2-todo-ktor/src/com/example/TodoMVCApplication.kt b/example/kotlinlib/web/2-todo-ktor/src/com/example/TodoMVCApplication.kt
@@ -0,0 +1,39 @@
+package com.example
+
+import io.ktor.server.application.*
+import io.ktor.server.engine.*
+import io.ktor.server.netty.*
+import io.ktor.server.thymeleaf.*
+import io.ktor.server.webjars.*
+import org.jetbrains.exposed.sql.Database
+import org.thymeleaf.templateresolver.ClassLoaderTemplateResolver
+
+fun main(args: Array<String>) {
+ val database = Database.connect("jdbc:h2:mem:regular;DB_CLOSE_DELAY=-1;", "org.h2.Driver")
+ val todoItemRepository = TodoItemRepositoryImpl(database)
+ embeddedServer(Netty, port = 8091, host = "0.0.0.0"){
+ app(todoItemRepository)
+ }.start(wait = true)
+}
+
+fun Application.configureTemplating() {
+ install(Thymeleaf) {
+ setTemplateResolver(ClassLoaderTemplateResolver().apply {
+ prefix = "templates/thymeleaf/"
+ suffix = ".html"
+ characterEncoding = "utf-8"
+ })
+ }
+}
+
+fun Application.configureWebjars() {
+ install(Webjars) {
+ path = "/webjars" //defaults to /webjars
+ }
+}
+
+fun Application.app(todoItemRepository: TodoItemRepository) {
+ configureTemplating()
+ configureWebjars()
+ configureRoutes(todoItemRepository)
+}