laminar-todoapp

laminar-todoapp.scala

//> using scala 3.6.3
//> using platform scala-js

//> using dep "org.scala-js::scalajs-dom::2.8.0"
//> using dep "com.raquo::laminar::17.2.0"

//> using jsModuleKind es
//> using jsModuleSplitStyleStr fewestmodules

package myapp

import org.scalajs.dom
import com.raquo.laminar.api.L.*

case class Todo(id: Int, text: String, completed: Boolean)

@main
def main(): Unit = {
  val container = dom.document.getElementById("app")
  
  // State management
  val todosVar = Var(Vector.empty[Todo])
  val inputVar = Var("")
  
  def addTodo(text: String): Unit =
    if text.trim.nonEmpty then
      val newTodo = Todo(
        id = System.currentTimeMillis().toInt,
        text = text.trim,
        completed = false
      )
      todosVar.update(_ :+ newTodo)
      inputVar.set("")

  def toggleTodo(id: Int): Unit =
    todosVar.update(_.map { todo =>
      if todo.id == id then todo.copy(completed = !todo.completed)
      else todo
    })

  def deleteTodo(id: Int): Unit =
    todosVar.update(_.filterNot(_.id == id))

  render(
    container,
    div(
      className := "max-w-md mx-auto mt-8 p-4",
      
      // Input form
      form(
        className := "flex gap-2 mb-4",
        onSubmit.preventDefault --> { _ => addTodo(inputVar.now()) },
        
        input(
          className := "flex-1 px-4 py-2 border rounded focus:outline-none focus:border-blue-500",
          placeholder := "Add a new todo...",
          controlled(
            value <-- inputVar,
            onInput.mapToValue --> inputVar
          )
        ),
        
        button(
          className := "px-4 py-2 bg-blue-500 text-white rounded hover:bg-blue-600",
          "Add"
        )
      ),
      
      // Todo list
      div(
        className := "space-y-2",
        children <-- todosVar.signal.map { todos =>
          todos.map { todo =>
            div(
              className := "flex items-center gap-2 p-2 border rounded",
              
              input(
                typ := "checkbox",
                checked := todo.completed,
                className := "h-5 w-5",
                onClick --> { _ => toggleTodo(todo.id) }
              ),
              
              span(
                className := (if todo.completed then "line-through text-gray-500" else ""),
                todo.text
              ),
              
              button(
                className := "ml-auto px-2 py-1 text-red-500 hover:bg-red-100 rounded",
                onClick --> { _ => deleteTodo(todo.id) },
                "×"
              )
            )
          }
        }
      )
    )
  )
}