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korolev.internal.ComponentInstance.scala Maven / Gradle / Ivy
/*
* Copyright 2017-2020 Aleksey Fomkin
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package korolev.internal
import korolev.*
import korolev.effect.{Effect, Queue, Reporter, Scheduler, Stream}
import korolev.effect.syntax.*
import korolev.state.{StateDeserializer, StateManager, StateSerializer}
import levsha.{Id, StatefulRenderContext}
import levsha.events.{EventId, EventPhase}
import scala.collection.mutable
import Context.*
import korolev.data.Bytes
import korolev.internal.Frontend.DomEventMessage
import korolev.util.{JsCode, Lens}
import korolev.web.FormData
import scala.collection.concurrent.TrieMap
import scala.concurrent.ExecutionContext
import scala.util.control.NonFatal
/**
* Component state holder and effects performer
*
* Performing cycle:
*
* 1. prepare()
* 2. Optionally setState()
* 3. applyRenderContext()
* 4. dropObsoleteMisc()
*
* @tparam AS Type of top level state (application state)
* @tparam CS Type of component state
*/
final class ComponentInstance[
F[_]: Effect,
AS: StateSerializer: StateDeserializer,
M,
CS: StateSerializer: StateDeserializer,
P,
E
](
nodeId: Id,
sessionId: Qsid,
frontend: Frontend[F],
eventRegistry: EventRegistry[F],
stateManager: StateManager[F],
val component: Component[F, CS, P, E],
stateQueue: Queue[F, (Id, Any, Option[Effect.Promise[Unit]])],
createMiscProxy: (StatefulRenderContext[Binding[F, AS, M]],
(StatefulRenderContext[Binding[F, CS, E]], Binding[F, CS, E]) => Unit) => StatefulRenderContext[
Binding[F, CS, E]],
scheduler: Scheduler[F],
reporter: Reporter,
recovery: PartialFunction[Throwable, F[Unit]],
) { self =>
import ComponentInstance._
import reporter.Implicit
private val miscLock = new Object()
private var lastParameters: P = _
private val markedDelays = mutable.Set.empty[Id] // Set of the delays which are should survive
private val markedComponentInstances = mutable.Set.empty[Id]
private val delays = mutable.Map.empty[Id, DelayInstance[F, CS, E]]
private val elements = mutable.Map.empty[ElementId, Id]
private val events = mutable.Map.empty[EventId, Vector[Event[F, CS, E]]]
private val nestedComponents = mutable.Map.empty[Id, ComponentInstance[F, CS, E, _, _, _]]
// Why we use '() => F[Unit]'? Because should
// support scala.concurrent.Future which is has
// strict semantic (runs immediately).
private val pendingEffects = Queue[F, () => F[Unit]]()
@volatile private var eventSubscription = Option.empty[E => _]
private[korolev] case class BrowserAccess(eventId: EventId) extends BaseAccessDefault[F, CS, E] {
private def getId(elementId: ElementId): F[Id] = Effect[F].delay {
unsafeGetId(elementId)
}
private def unsafeGetId(elementId: ElementId): Id = {
// miscLock synchronization required
// because prop handler methods can be
// invoked during render.
miscLock.synchronized {
elements.get(elementId) match {
case None =>
elementId.name match {
case Some(name) => throw new Exception(s"No element matched for accessor $name")
case None => throw new Exception(s"No element matched for accessor")
}
case Some(id) => id
}
}
}
def property(elementId: ElementId): PropertyHandler[F] = {
val idF = getId(elementId)
new PropertyHandler[F] {
def get(propName: String): F[String] = idF.flatMap { id =>
frontend.extractProperty(id, propName)
}
def set(propName: String, value: Any): F[Unit] = idF.flatMap { id =>
// XmlNs argument is empty cause it will be ignored
frontend.setProperty(id, propName, value)
}
}
}
def focus(element: ElementId): F[Unit] =
getId(element).flatMap { id =>
frontend.focus(id)
}
def publish(message: E): F[Unit] =
Effect[F].delay(eventSubscription.foreach(f => f(message)))
def state: F[CS] = {
val state = stateManager.read[CS](nodeId)
state.map(_.getOrElse(throw new RuntimeException("State is empty")))
}
def sessionId: F[Qsid] = Effect[F].delay(self.sessionId)
def transition(f: Transition[CS]): F[Unit] = applyTransition(x => Effect[F].pure(f(x)))
def transitionForce(f: Transition[CS]): F[Unit] = applyTransitionForce(x => Effect[F].pure(f(x)))
def transitionAsync(f: TransitionAsync[F, CS]): F[Unit] = applyTransition(f)
def transitionForceAsync(f: TransitionAsync[F, CS]): F[Unit] = applyTransitionForce(f)
def downloadFormData(element: ElementId): F[FormData] =
for {
id <- getId(element)
formData <- frontend.uploadForm(id)
} yield formData
def downloadFiles(id: ElementId): F[List[(FileHandler, Bytes)]] = {
downloadFilesAsStream(id).flatMap { streams =>
Effect[F].sequence {
streams.map {
case (handler, data) =>
data
.fold(Bytes.empty)(_ ++ _)
.map(b => (handler, b))
}
}
}
}
def downloadFilesAsStream(id: ElementId): F[List[(FileHandler, Stream[F, Bytes])]] = {
listFiles(id).flatMap { handlers =>
Effect[F].sequence {
handlers.map { handler =>
downloadFileAsStream(handler).map(f => (handler, f))
}
}
}
}
/**
* Get selected file as a stream from input
*/
def downloadFileAsStream(handler: FileHandler): F[Stream[F, Bytes]] = {
for {
id <- getId(handler.elementId)
streams <- frontend.uploadFile(id, handler)
} yield streams
}
def listFiles(elementId: ElementId): F[List[FileHandler]] =
for {
id <- getId(elementId)
files <- frontend.listFiles(id)
} yield {
files.map {
case (fileName, size) =>
FileHandler(fileName, size)(elementId)
}
}
def uploadFile(name: String, stream: Stream[F, Bytes], size: Option[Long], mimeType: String): F[Unit] =
frontend.downloadFile(name, stream, size, mimeType)
def resetForm(elementId: ElementId): F[Unit] =
getId(elementId).flatMap { id =>
frontend.resetForm(id)
}
def evalJs(code: JsCode): F[String] =
frontend.evalJs(code.mkString(unsafeGetId))
def eventData: F[String] = frontend.extractEventData(eventId)
def registerCallback(name: String)(f: String => F[Unit]): F[Unit] =
frontend.registerCustomCallback(name)(f)
}
private[korolev] val browserAccess = BrowserAccess(EventId(Id.TopLevel, "init", EventPhase.AtTarget))
/**
* Subscribes to component instance events.
* Callback will be invoked on call of `access.publish()` in the
* component instance context.
*/
def setEventsSubscription(callback: E => _): Unit = {
eventSubscription = Some(callback)
}
def applyRenderContext(parameters: P,
rc: StatefulRenderContext[Binding[F, AS, M]],
snapshot: StateManager.Snapshot): Unit = miscLock.synchronized {
// Reset all event handlers delays and elements
prepare()
val state = snapshot[CS](nodeId).map(Right(_)).getOrElse(component.initialState)
val node = state match {
case Right(value) =>
if (lastParameters != parameters) {
component.maybeUpdateState(parameters, value) match {
case None => ()
case Some(effect) =>
effect.flatMap { newState =>
stateManager.write(nodeId, newState) *>
stateQueue.enqueue(nodeId, newState, None)
}.runAsyncForget // TODO Should be cancelable
}
}
component.render(parameters, value)
case Left(generateState) =>
generateState(parameters).flatMap { newState =>
stateManager.write(nodeId, newState) *>
stateQueue.enqueue(nodeId, newState, None)
}.runAsyncForget // TODO Should be cancelable
component.renderNoState(parameters)
}
lastParameters = parameters
val proxy = createMiscProxy(
rc, { (proxy, misc) =>
misc match {
case event: Event[F, CS, E] =>
val id = rc.currentContainerId
val eid = EventId(id, event.`type`, event.phase)
val es = events.getOrElseUpdate(eid, Vector.empty)
events.put(eid, es :+ event)
eventRegistry.registerEventType(event.`type`)
case element: ElementId =>
val id = rc.currentContainerId
elements.put(element, id)
()
case delay: Delay[F, CS, E] =>
val id = rc.currentContainerId
markedDelays += id
if (!delays.contains(id)) {
val delayInstance = new DelayInstance(delay, scheduler, reporter)
delays.put(id, delayInstance)
delayInstance.start(browserAccess)
}
case entry: ComponentEntry[F, CS, E, Any, Any, Any] =>
val id = rc.subsequentId
nestedComponents.get(id) match {
case Some(n: ComponentInstance[F, CS, E, Any, Any, Any]) if n.component.id == entry.component.id =>
// Use nested component instance
markedComponentInstances += id
n.setEventsSubscription((e: Any) => entry.eventHandler(browserAccess, e).runAsyncForget)
n.applyRenderContext(entry.parameters, proxy, snapshot)
case _ =>
val n = entry.createInstance(
id,
sessionId,
frontend,
eventRegistry,
stateManager,
stateQueue,
scheduler,
reporter,
recovery
)
markedComponentInstances += id
nestedComponents.put(id, n)
n.unsafeInitialize()
n.setEventsSubscription((e: Any) => entry.eventHandler(browserAccess, e).runAsyncForget)
n.applyRenderContext(entry.parameters, proxy, snapshot)
}
}
}
)
node(proxy)
}
private def applyTransitionEffect(transition: TransitionAsync[F, CS]): F[CS] =
for {
maybeState <- stateManager.read[CS](nodeId)
state <- maybeState
.orElse(component.initialState.toOption)
.fold(Effect[F].fail(new Exception("Uninitialized component state")): F[CS])(Effect[F].pure(_))
newState <- transition(state)
_ <- stateManager.write(nodeId, newState)
} yield newState
private def applyTransition(transition: TransitionAsync[F, CS]): F[Unit] = {
val effect = () =>
for {
newState <- applyTransitionEffect(transition)
_ <- stateQueue.enqueue(nodeId, newState, None)
} yield ()
pendingEffects.enqueue(effect)
}
private def applyTransitionForce(transition: TransitionAsync[F, CS]): F[Unit] = Effect[F].promiseF[Unit] { cb =>
val effect = () =>
for {
newState <- applyTransitionEffect(transition).recoverF {
case e =>
cb(Left(e))
Effect[F].fail[CS](e)
}
_ <- stateQueue.enqueue(nodeId, newState, Some(cb))
} yield ()
pendingEffects.enqueue(effect)
}
def applyEvent(eventId: EventId, dem: DomEventMessage, rnMap: TrieMap[(Id, String), Int]): Boolean = {
try {
events.get(eventId) match {
case Some(events: Vector[Event[F, CS, E]]) =>
// A user defines the event effect, so we
// don't control the time of execution.
// We shouldn't block the application if
// the user's code waits for something
// for a long time.
events.forall { event =>
val k = (eventId.target, eventId.`type`)
if (rnMap.getOrElse(k, 0) == dem.eventCounter) {
val newEventConter = dem.eventCounter + 1
rnMap.put(k, newEventConter)
event.effect(BrowserAccess(eventId))
.after(frontend.setEventCounter(eventId.target, eventId.`type`, newEventConter))
.runAsync {
case Left(e) => reporter.error(s"Event handler for ${eventId.`type`} at ${eventId.target} failed", e)
case _ => () // Do nothing
}
!event.stopPropagation
} else {
true
}
}
case None =>
nestedComponents.values.forall { nested =>
nested.applyEvent(eventId, dem, rnMap)
}
}
} catch {
case NonFatal(ex) =>
recovery(ex).runAsyncForget
// Stop event propagation because error happen
false
}
}
/**
* Remove all delays and nested component instances
* which were not marked during applying render context.
*/
def dropObsoleteMisc(): Unit = miscLock.synchronized {
delays foreach {
case (id, delay) =>
if (!markedDelays.contains(id)) {
delays.remove(id)
delay.cancel()
}
}
nestedComponents foreach {
case (id, nested) =>
if (!markedComponentInstances.contains(id)) {
nestedComponents.remove(id)
nested
.destroy()
.after(stateManager.delete(id))
.runAsyncForget
} else nested.dropObsoleteMisc()
}
}
/**
* Prepares component instance to applying render context.
* Removes all temporary and obsolete misc.
* All nested components also will be prepared.
*/
private def prepare(): Unit = {
markedComponentInstances.clear()
markedDelays.clear()
elements.clear()
events.clear()
// Remove only finished delays
delays foreach {
case (id, delay) =>
if (delay.isFinished)
delays.remove(id)
}
}
/**
* Close 'pendingEffects' in this component and
* all nested components.
*
* MUST be invoked after closing connection.
*/
def destroy(): F[Unit] =
for {
_ <- pendingEffects.close()
_ <- nestedComponents.values.toList
.map(_.destroy())
.sequence
.unit
} yield ()
private def applyPendingEffect(f: () => F[Unit]): F[Unit] =
f().recover { case e => reporter.error("Transition failed", e) }
protected def unsafeInitialize(): Unit =
pendingEffects.stream
.foreach(applyPendingEffect)
.runAsyncForget
// Execute effects sequentially
def initialize()(implicit ec: ExecutionContext): F[Effect.Fiber[F, Unit]] =
Effect[F].start(pendingEffects.stream.foreach(applyPendingEffect))
}
private object ComponentInstance {
import Context.Access
import Context.Delay
final class DelayInstance[F[_]: Effect, S, M](delay: Delay[F, S, M], scheduler: Scheduler[F], reporter: Reporter) {
@volatile private var handler = Option.empty[Scheduler.JobHandler[F, _]]
@volatile private var finished = false
def isFinished: Boolean = finished
def cancel(): Unit = {
handler.foreach(_.unsafeCancel())
}
def start(access: Access[F, S, M]): Unit = {
handler = Some {
scheduler.unsafeScheduleOnce(delay.duration) {
finished = true
delay.effect(access)
}
}
}
}
}