Lift Framework example source code file (CometActor.scala)
The Lift Framework CometActor.scala source code
/*
* Copyright 2007-2011 WorldWide Conferencing, LLC
*
* 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 net.liftweb
package http
import net.liftweb.common._
import net.liftweb.actor._
import scala.collection.mutable.{ListBuffer}
import net.liftweb.util.Helpers._
import net.liftweb.util._
import net.liftweb.json._
import scala.xml.{NodeSeq, Text, Elem, Node, Group, Null, PrefixedAttribute, UnprefixedAttribute}
import scala.collection.immutable.TreeMap
import scala.collection.mutable.{HashSet, ListBuffer}
import net.liftweb.http.js._
import JsCmds._
import JE._
import java.util.concurrent.atomic.AtomicLong
import java.util.Locale
/**
* An actor that monitors other actors that are linked with it. If a watched
* actor terminates,this actor captures the Exit messag, executes failureFuncs
* and resurects the actor.
*/
object ActorWatcher extends scala.actors.Actor with Loggable {
import scala.actors.Actor._
def act = loop {
react {
case scala.actors.Exit(actor: scala.actors.Actor, why: Throwable) =>
failureFuncs.foreach(f => tryo(f(actor, why)))
case _ =>
}
}
private def startAgain(a: scala.actors.Actor, ignore: Throwable) {
a.start
a ! RelinkToActorWatcher
}
private def logActorFailure(actor: scala.actors.Actor, why: Throwable) {
logger.warn("The ActorWatcher restarted " + actor + " because " + why, why)
}
/**
* If there's something to do in addition to starting the actor up, pre-pend the
* actor to this List
*/
@volatile var failureFuncs: List[(scala.actors.Actor, Throwable) => Unit] = logActorFailure _ ::
startAgain _ :: Nil
this.trapExit = true
this.start
}
/**
* This is used as an indicator message for linked actors.
*
* @see ActorWatcher
*/
case object RelinkToActorWatcher
trait DeltaTrait {
def toJs: JsCmd
}
trait CometState[DeltaType <: DeltaTrait,
MyType <: CometState[DeltaType, MyType]] {
self: MyType =>
def -(other: MyType): Seq[DeltaType]
def render: NodeSeq
}
trait CometStateWithUpdate[UpdateType, DeltaType <: DeltaTrait,
MyType <: CometStateWithUpdate[UpdateType,
DeltaType, MyType]]
extends CometState[DeltaType, MyType]
{
self: MyType =>
def process(in: UpdateType): MyType
}
trait StatefulComet extends CometActor {
type Delta <: DeltaTrait
type State <: CometState[Delta, State]
/**
* Test the parameter to see if it's an updated state object
*/
def testState(in: Any): Box[State]
/**
* Return the empty state object
*/
def emptyState: State
/**
* The current state objects
*/
protected var state: State = emptyState
/**
* If there's some ThreadLocal variable that needs to be setup up
* before processing the state deltas, set it up here.
*/
protected def setupLocalState[T](f: => T): T = f
private[http] override val _lowPriority = {
val pf: PartialFunction[Any, Unit] = {
case v if testState(v).isDefined =>
testState(v).foreach {
ns =>
if (ns ne state) {
val diff = ns - state
state = ns
partialUpdate(setupLocalState {diff.map(_.toJs).foldLeft(Noop)(_ & _)})
}
}
}
pf orElse super._lowPriority
}
/**
* The Render method
*/
def render = state.render
}
object CurrentCometActor extends ThreadGlobal[LiftCometActor]
object AddAListener {
def apply(who: SimpleActor[Any]) = new AddAListener(who, { case _ => true } )
}
/**
* This is a message class for use with ListenerManager and CometListener
* instances. The use of the shouldUpdate function is deprecated, and
* should instead be handled by the message processing partial functions
* on the CometListner instances themselves.
*
* @see CometListener
* @see ListenerManager
*/
case class AddAListener(who: SimpleActor[Any], shouldUpdate: PartialFunction[Any, Boolean])
/**
* This is a message class for use with ListenerManager and CometListener
* instances.
*
* @see CometListener
* @see ListenerManager
*/
case class RemoveAListener(who: SimpleActor[Any])
object ListenerManager {
type ActorTest = (SimpleActor[Any], PartialFunction[Any, Boolean])
}
/**
* This trait manages a set of Actors in a publish/subscribe pattern. When you extend your Actor with
* this trait, you automatically get handling for sending messages out to all subscribed Actors. Simply
* override the high-, medium-, or lowPriority handlers to do your message processing. When you want to update
* all subscribers, just call the updateListeners method. The createUpdate method is used to generate
* the message that you want sent to all subscribers.
*
* Note that the AddAListener and RemoveAListener messages (for subscription control) are processed
* after any highPriority or mediumPriority messages are processed, so take care to avoid overly
* broad matches in those handlers that might consume internal messages.
*
* For example, you could write a simple service to provide clock ticks using the following code:
*
* <pre name="code" class="scala">
* case object Tick
*
* object Ticker extends ListenerManager {
* import net.liftweb.util.ActorPing
*
* // Set up the initial tick
* ActorPing.schedule(this, Tick, 1000L)
*
* // This is a placeholder, since we're only interested
* // in Ticks
* def createUpdate = "Registered"
*
* override def mediumPriority = {
* case Tick => {
* updateListeneres(Tick)
* ActorPing.schedule(this, Tick, 1000L)
* }
* }
* }
* </pre>
*
* A client CometActor could look like:
*
* <pre name="code" class="scala">
* class CometClock extends CometListener {
* val registerWith = Ticker
*
* ... handling code ...
* }
* </pre>
*
* @see CometListener
*
*/
trait ListenerManager {
self: SimpleActor[Any] =>
import ListenerManager._
/**
* This is the list of all registered actors
*/
private var listeners: List[ActorTest] = Nil
protected def messageHandler: PartialFunction[Any, Unit] =
highPriority orElse mediumPriority orElse
listenerService orElse lowPriority
protected def listenerService: PartialFunction[Any, Unit] =
{
case AddAListener(who, shouldUpdate) =>
val pair = (who, shouldUpdate)
listeners ::= pair
updateIfPassesTest(createUpdate)(pair)
case RemoveAListener(who) =>
listeners = listeners.filter(_._1 ne who)
}
/**
* Update the listeners with the message generated by createUpdate
*/
protected def updateListeners() {
val update = updateIfPassesTest(createUpdate) _
listeners foreach update
}
/**
* Update the listeners with a message that we create. Note that
* with this invocation the createUpdate method is not used.
*/
protected def updateListeners(msg: Any) {
listeners foreach (_._1 ! msg)
}
/**
* This method provides legacy functionality for filtering messages
* before sending to each registered actor. It is deprecated in
* favor of doing the filtering in the registered Actor's
* message handling partial functions instead.
*/
@deprecated("Accept/reject logic should be done in the partial function that handles the message.")
protected def updateIfPassesTest(update: Any)(info: ActorTest) {
info match {
case (who, test) => if (test.isDefinedAt(update) && test(update)) who ! update
}
}
/**
* This method is called when the <pre>updateListeners() method
* needs a message to send to subscribed Actors. In particular, createUpdate
* is used to create the first message that a newly subscribed CometListener
* will receive.
*/
protected def createUpdate: Any
/**
* Override this method to process high priority messages. Note:
* <b>you must not process messages with a wildcard (match all), since
* this will intercept the messages used for subscription control.
*/
protected def highPriority: PartialFunction[Any, Unit] = Map.empty
/**
* Override this method to process medium priority messages. See
* the highPriority method for an important note on wildcard
* processing.
*
* @see #highPriority
*/
protected def mediumPriority: PartialFunction[Any, Unit] = Map.empty
/**
* Override this method to process low priority messages.
*/
protected def lowPriority: PartialFunction[Any, Unit] = Map.empty
}
/**
* This is a legacy trait, left over from Lift's
* Scala 2.7 support. You should use or migrate to
* CometListener instead.
*
* @see CometListener
*/
@deprecated("Use the CometListener trait instead.")
trait CometListenee extends CometListener {
self: CometActor =>
}
/**
* A LiftActorJ with ListenerManager. Subclass this class
* to get a Java-useable LiftActorJ with ListenerManager
*/
abstract class LiftActorJWithListenerManager extends LiftActorJ with ListenerManager {
protected override def messageHandler: PartialFunction[Any, Unit] =
highPriority orElse mediumPriority orElse
listenerService orElse lowPriority orElse _messageHandler
}
/**
* This trait adds functionality to automatically register with a given
* Actor using AddAListener and RemoveAListener control messages. The most
* typical usage would be to register with an instance of ListenerManager.
* You will need to provide a def/val for the <pre>registerWith member
* to control which Actor to connect to.
*
* See ListenerManager for a complete example.
*
* @see ListenerManager
*/
trait CometListener extends CometActor {
self: CometActor =>
/**
* This controls which Actor to register with for updates. Typically
* this will be an instance of ListenerActor, although you can provide
* your own subscription handling on top of any SimpleActor.
*/
protected def registerWith: SimpleActor[Any]
/**
* Override this in order to selectively update listeners based on the given message.
* This method has been deprecated because it's executed in a seperate context from
* the session's context. This causes problems. Accept/reject logic should be done
* in the partial function that handles the message.
*/
@deprecated("Accept/reject logic should be done in the partial function that handles the message.")
protected def shouldUpdate: PartialFunction[Any, Boolean] = { case _ => true}
abstract override protected def localSetup() {
registerWith ! AddAListener(this, shouldUpdate)
super.localSetup()
}
abstract override protected def localShutdown() {
registerWith ! RemoveAListener(this)
super.localShutdown()
}
}
trait LiftCometActor extends TypedActor[Any, Any] with ForwardableActor[Any, Any] with Dependent {
def uniqueId: String
private[http] def callInitCometActor(theSession: LiftSession,
theType: Box[String],
name: Box[String],
defaultHtml: NodeSeq,
attributes: Map[String, String]) {
initCometActor(theSession, theType, name, defaultHtml, attributes)
}
protected def initCometActor(theSession: LiftSession,
theType: Box[String],
name: Box[String],
defaultHtml: NodeSeq,
attributes: Map[String, String]): Unit
def jsonCall: JsonCall
def theType: Box[String]
def name: Box[String]
def hasOuter: Boolean
def buildSpan(time: Long, xml: NodeSeq): NodeSeq
def parentTag: Elem
/**
* Poke the CometActor and cause it to do a partial update Noop which
* will have the effect of causing the component to redisplay any
* Wiring elements on the component.
* This method is Actor-safe and may be called from any thread, not
* just the Actor's message handler thread.
*/
def poke(): Unit = {}
/**
* Is this CometActor going to capture the initial Req
* object? If yes, override this method and return true
* and override captureInitialReq to capture the Req. Why
* have to explicitly ask for the Req? In order to send Req
* instances across threads, the Req objects must be snapshotted
* which is the process of reading the POST or PUT body from the
* HTTP request stream. We don't want to do this unless we
* have to, so by default the Req is not snapshotted/sent. But
* if you want it, you can have it.
*/
def sendInitialReq_? : Boolean = false
/**
* If the predicate cell changes, the Dependent will be notified
*/
def predicateChanged(which: Cell[_]): Unit = {poke()}
/**
* The locale for the session that created the CometActor
*/
def cometActorLocale: Locale = _myLocale
private var _myLocale = Locale.getDefault()
private[http] def setCometActorLocale(loc: Locale) {
_myLocale = loc
}
}
/**
* Subclass from this class if you're in Java-land
* and want a CometActor
*/
abstract class CometActorJ extends LiftActorJ with CometActor {
override def lowPriority = _messageHandler
}
/**
* Subclass from this class if you want a CometActorJ with
* CometListeners
*/
abstract class CometActorJWithCometListener extends CometActorJ with CometListener {
override def lowPriority = _messageHandler
}
/**
* Takes care of the plumbing for building Comet-based Web Apps
*/
trait CometActor extends LiftActor with LiftCometActor with BindHelpers {
private val logger = Logger(classOf[CometActor])
val uniqueId = Helpers.nextFuncName
private var spanId = uniqueId
private var lastRenderTime = Helpers.nextNum
/**
* If we're going to cache the last rendering, here's the
* private cache
*/
private[this] var _realLastRendering: RenderOut = _
/**
* The last rendering (cached or not)
*/
private def lastRendering: RenderOut =
if (dontCacheRendering) {
val ret = (render ++ jsonInCode): RenderOut
theSession.updateFunctionMap(S.functionMap, spanId, lastRenderTime)
ret
} else {
_realLastRendering
}
/**
* set the last rendering... ignore if we're not caching
*/
private def lastRendering_=(last: RenderOut) {
if (!dontCacheRendering) {
_realLastRendering = last
}
}
private var wasLastFullRender = false
@transient
private var listeners: List[(ListenerId, AnswerRender => Unit)] = Nil
private var askingWho: Box[LiftCometActor] = Empty
private var whosAsking: Box[LiftCometActor] = Empty
private var answerWith: Box[Any => Any] = Empty
private var deltas: List[Delta] = Nil
private var jsonHandlerChain: PartialFunction[Any, JsCmd] = Map.empty
private val notices = new ListBuffer[(NoticeType.Value, NodeSeq, Box[String])]
private var lastListenTime = millis
private var _theSession: LiftSession = _
def theSession = _theSession
@volatile private var _defaultHtml: NodeSeq = _
@deprecated("Use defaultHtml")
def defaultXml = _defaultHtml
/**
* The template that was passed to this component during comet
* initializations
*/
def defaultHtml: NodeSeq = _defaultHtml
private var _name: Box[String] = Empty
/**
* The optional name of this CometActors
*/
def name: Box[String] = _name
private var _theType: Box[String] = Empty
/**
* The optional type of this CometActor
*/
def theType: Box[String] = _theType
private var _attributes: Map[String, String] = Map.empty
def attributes = _attributes
/**
* The lifespan of this component. By default CometActors
* will last for the entire session that they were created in,
* even if the CometActor is not currently visible. You can
* set the lifespan of the CometActor. If the CometActor
* isn't visible on any page for some period after its lifespan
* the CometActor will be shut down.
*/
def lifespan: Box[TimeSpan] = Empty
private var _running = true
private var _shutDownAt = millis
/**
* Is the CometActor running?
*/
protected def running = _running
/**
* It's seriously suboptimal to override this method. Instead
* use localSetup()
*/
protected def initCometActor(theSession: LiftSession,
theType: Box[String],
name: Box[String],
defaultHtml: NodeSeq,
attributes: Map[String, String]) {
if (!dontCacheRendering) {
lastRendering = RenderOut(Full(defaultHtml),
Empty, Empty, Empty, false)
}
this._theType = theType
this._theSession = theSession
this._defaultHtml = defaultHtml
this._name = name
this._attributes = attributes
}
def defaultPrefix: Box[String] = Empty
private lazy val _defaultPrefix: String = (defaultPrefix or _name) openOr "comet"
/**
* Set to 'true' if we should run "render" on every page load
*/
protected def devMode = false
def hasOuter = true
def parentTag = <div style="display: inline"/>
/**
* Return the list of ListenerIds of all long poll agents that
* are waiting for this CometActor to change its state. This method
* is useful for detecting presence.
*/
protected def cometListeners: List[ListenerId] = listeners.map(_._1)
/**
* This method will be called when there's a change in the long poll
* listeners. The method does nothing, but allows you to get a granular
* sense of how many browsers care about this CometActor. Note that
* this method should not block for any material time and if there's
* any processing to do, use Scheduler.schedule or send a message to this
* CometActor. Do not change the Actor's state from this method.
*/
protected def listenerTransition(): Unit = {}
private def _handleJson(in: Any): JsCmd =
if (jsonHandlerChain.isDefinedAt(in))
jsonHandlerChain(in)
else handleJson(in)
/**
* Prepends the handler to the Json Handlers. Should only be used
* during instantiation
*
* @param h -- the PartialFunction that can handle a JSON request
*/
def appendJsonHandler(h: PartialFunction[Any, JsCmd]) {
jsonHandlerChain = h orElse jsonHandlerChain
}
def handleJson(in: Any): JsCmd = Noop
/**
* If there's actor-specific JSON behavior on failure to make the JSON
* call, include the JavaScript here.
*/
def onJsonError: Box[JsCmd] = Empty
lazy val (jsonCall, jsonInCode) = S.buildJsonFunc(Full(_defaultPrefix), onJsonError, _handleJson)
/**
* Override this method to deal with JSON sent from the browser via the sendJson function. This
* is based on the Lift JSON package rather than the handleJson stuff based on the older util.JsonParser. This
* is the prefered mechanism. If you use the jsonSend call, you will get a JObject(JField("command", cmd), JField("param", params))
*/
def receiveJson: PartialFunction[JsonAST.JValue, JsCmd] = Map()
/**
* The JavaScript call that you use to send the data to the server. For example:
* <button onclick={jsonSend("Hello", JsRaw("Dude".encJs))}>Click</button>
*/
def jsonSend: JsonCall = _sendJson
/**
* The call that packages up the JSON and tosses it to the server. If you set autoIncludeJsonCode to true,
* then this will be included in the stuff sent to the server.
*/
def jsonToIncludeInCode: JsCmd = _jsonToIncludeCode
private lazy val (_sendJson, _jsonToIncludeCode) = S.createJsonFunc(Full(_defaultPrefix), onJsonError, receiveJson _)
/**
* Set this method to true to have the Json call code included in the Comet output
*/
def autoIncludeJsonCode: Boolean = false
/**
* Creates the span element acting as the real estate for commet rendering.
*/
def buildSpan(time: Long, xml: NodeSeq): NodeSeq = {
Elem(parentTag.prefix, parentTag.label, parentTag.attributes,
parentTag.scope, Group(xml)) %
new UnprefixedAttribute("id",
Text(spanId),
if (time > 0L) {
new PrefixedAttribute("lift", "when",
time.toString,
Null)
} else {Null})
}
protected override def messageHandler = {
val what = composeFunction
val myPf: PartialFunction[Any, Unit] = new PartialFunction[Any, Unit] {
def apply(in: Any): Unit =
CurrentCometActor.doWith(CometActor.this) {
S.initIfUninitted(theSession) {
RenderVersion.doWith(uniqueId) {
S.functionLifespan(true) {
what.apply(in)
if (S.functionMap.size > 0) {
theSession.updateFunctionMap(S.functionMap,
uniqueId, lastRenderTime)
S.clearFunctionMap
}
}
}
}
}
def isDefinedAt(in: Any): Boolean =
CurrentCometActor.doWith(CometActor.this) {
S.initIfUninitted(theSession) {
RenderVersion.doWith(uniqueId) {
S.functionLifespan(true) {
what.isDefinedAt(in)
}
}
}
}
}
myPf
}
/**
* A part of the CometActor's screen real estate that is not
* updated by default with reRender(). This block of HTML is
* useful for the editor part of a Comet-based control where
* the data is JSON and updated with partialUpdates.
*/
def fixedRender: Box[NodeSeq] = Empty
/**
* Calculate fixedRender and capture the postpage javascript
*/
protected def calcFixedRender: Box[NodeSeq] =
fixedRender.map(ns => theSession.postPageJavaScript() match {
case Nil => ns
case xs => {
ns ++ Script(xs)
}
})
/**
* We have to cache fixedRender and only change it if
* the tempalte changes or we get a reRender(true)
*/
private def internalFixedRender: Box[NodeSeq] =
if (!cacheFixedRender) {
calcFixedRender
} else {
cachedFixedRender.get
}
private val cachedFixedRender: FatLazy[Box[NodeSeq]] = FatLazy(calcFixedRender)
/**
* By default, we do not cache the value of fixedRender. If it's
* expensive to recompute it each time there's a convertion
* of something to a RenderOut, override this method if you
* want to cache fixedRender
*/
protected def cacheFixedRender = false
/**
* A helpful implicit conversion that takes a NodeSeq => NodeSeq
* (for example a CssSel) and converts it to a Box[NodeSeq] by
* applying the function to defaultHtml
*/
protected implicit def nodeSeqFuncToBoxNodeSeq(f: NodeSeq => NodeSeq):
Box[NodeSeq] = Full(f(defaultHtml))
/**
* Handle messages sent to this Actor before the
*/
def highPriority: PartialFunction[Any, Unit] = Map.empty
def lowPriority: PartialFunction[Any, Unit] = Map.empty
def mediumPriority: PartialFunction[Any, Unit] = Map.empty
private[http] def _lowPriority: PartialFunction[Any, Unit] = {
case s => logger.debug("CometActor " + this + " got unexpected message " + s)
}
private lazy val _mediumPriority: PartialFunction[Any, Unit] = {
case l@Unlisten(seq) => {
lastListenTime = millis
askingWho match {
case Full(who) => forwardMessageTo(l, who) // forward l
case _ => listeners = listeners.filter(_._1 != seq)
}
listenerTransition()
}
case l@Listen(when, seqId, toDo) => {
lastListenTime = millis
askingWho match {
case Full(who) => forwardMessageTo(l, who) // who forward l
case _ =>
if (when < lastRenderTime) {
toDo(AnswerRender(new XmlOrJsCmd(spanId, lastRendering,
buildSpan _, notices toList),
whosAsking openOr this, lastRenderTime, wasLastFullRender))
clearNotices
} else {
deltas.filter(_.when > when) match {
case Nil => listeners = (seqId, toDo) :: listeners
case all@(hd :: xs) =>
toDo(AnswerRender(new XmlOrJsCmd(spanId, Empty, Empty,
Full(all.reverse.foldLeft(Noop)(_ & _.js)), Empty, buildSpan, false, notices toList),
whosAsking openOr this, hd.when, false))
clearNotices
}
}
}
listenerTransition()
}
case PerformSetupComet2(initialReq) => {
// this ! RelinkToActorWatcher
localSetup()
captureInitialReq(initialReq)
performReRender(true)
}
/**
* Update the defaultHtml... sent in dev mode
*/
case UpdateDefaultXml(xml) => {
val redo = xml != _defaultHtml
_defaultHtml = xml
if (redo) {
performReRender(false)
}
}
case AskRender =>
askingWho match {
case Full(who) => forwardMessageTo(AskRender, who) // forward AskRender
case _ => {
if (!deltas.isEmpty || devMode) performReRender(false)
reply(AnswerRender(new XmlOrJsCmd(spanId, lastRendering,
buildSpan _, notices toList),
whosAsking openOr this, lastRenderTime, true))
clearNotices
}
}
case ActionMessageSet(msgs, req) =>
S.doCometParams(req.params) {
S.jsToAppend() match {
case Nil =>
case js => partialUpdate(js)
}
reply(msgs.map(_()) ::: List(S.noticesToJsCmd))
}
case AskQuestion(what, who, otherlisteners) => {
this.spanId = who.uniqueId
this.listeners = otherlisteners ::: this.listeners
startQuestion(what)
whosAsking = Full(who)
this.reRender(true)
listenerTransition()
}
case AnswerQuestion(what, otherListeners) =>
askingWho.foreach {
ah => {
reply("A null message to release the actor from its send and await reply... do not delete this message")
// askingWho.unlink(self)
ah ! ShutDown
this.listeners = this.listeners ::: otherListeners
this.askingWho = Empty
val aw = answerWith
answerWith = Empty
aw.foreach(_(what))
performReRender(true)
listenerTransition()
}
}
case ShutdownIfPastLifespan =>
for{
ls <- lifespan if listeners.isEmpty && (lastListenTime + ls.millis) < millis
} {
this ! ShutDown
}
case ReRender(all) => performReRender(all)
case Error(id, node) => notices += ((NoticeType.Error, node, id))
case Warning(id, node) => notices += ((NoticeType.Warning, node, id))
case Notice(id, node) => notices += ((NoticeType.Notice, node, id))
case ClearNotices => clearNotices
case ShutDown =>
logger.info("The CometActor " + this + " Received Shutdown")
askingWho.foreach(_ ! ShutDown)
theSession.removeCometActor(this)
_localShutdown()
case PartialUpdateMsg(cmdF) => {
val cmd: JsCmd = cmdF.apply
val time = Helpers.nextNum
val delta = JsDelta(time, cmd)
theSession.updateFunctionMap(S.functionMap, uniqueId, time)
S.clearFunctionMap
val m = millis
deltas = (delta :: deltas).filter(d => (m - d.timestamp) < 120000L)
if (!listeners.isEmpty) {
val postPage = theSession.postPageJavaScript()
val rendered =
AnswerRender(new XmlOrJsCmd(spanId, Empty, Empty,
Full(cmd & postPage),
Empty, buildSpan, false,
notices toList),
whosAsking openOr this, time, false)
clearNotices
listeners.foreach(_._2(rendered))
listeners = Nil
listenerTransition()
}
}
}
/**
* It's the main method to override, to define what is rendered by the CometActor
*
* There are implicit conversions for a bunch of stuff to
* RenderOut (including NodeSeq). Thus, if you don't declare the return
* turn to be something other than RenderOut and return something that's
* coersable into RenderOut, the compiler "does the right thing"(tm) for you.
* <br/>
* There are implicit conversions for NodeSeq, so you can return a pile of
* XML right here. There's an implicit conversion for NodeSeq => NodeSeq,
* so you can return a function (e.g., a CssBindFunc) that will convert
* the defaultHtml to the correct output. There's an implicit conversion
* from JsCmd, so you can return a pile of JavaScript that'll be shipped
* to the browser.<br/>
* Note that the render method will be called each time a new browser tab
* is opened to the comet component or the comet component is otherwise
* accessed during a full page load (this is true if a partialUpdate
* has occured.) You may want to look at the fixedRender method which is
* only called once and sets up a stable rendering state.
*/
def render: RenderOut
/**
* Cause the entire component to be reRendered and pushed out
* to any listeners. This method will cause the entire component
* to be rendered which can result in a huge blob of JavaScript to
* be sent to the client. It's a much better practice to use
* partialUpdate for non-trivial CometActor components.
*
* @param sendAll -- Should the fixed part of the CometActor be
* rendered.
*/
def reRender(sendAll: Boolean) {
this ! ReRender(sendAll)
}
/**
* Cause the entire component to be reRendered and pushed out
* to any listeners. This method will cause the entire component
* to be rendered which can result in a huge blob of JavaScript to
* be sent to the client. It's a much better practice to use
* partialUpdate for non-trivial CometActor components.
*/
def reRender() {reRender(false)}
/**
* Set this method to true if you want to avoid caching the
* rendering. This trades space for time.
*/
protected def dontCacheRendering: Boolean = false
/**
* Clear the common dependencies for Wiring. This
* method will clearPostPageJavaScriptForThisPage() and
* unregisterFromAllDependencies(). The combination
* will result in a clean slate for Wiring during a redraw.
* You can change the behavior of the wiring dependency management
* by overriding this method
*/
protected def clearWiringDependencies() {
if (!manualWiringDependencyManagement) {
theSession.clearPostPageJavaScriptForThisPage()
unregisterFromAllDepenencies()
}
}
/**
* By default, Lift deals with managing wiring dependencies.
* This means on each full render (a full render will
* happen on reRender() or on a page load if there have been
* partial updates.) You may want to manually deal with
* wiring dependencies. If you do, override this method
* and return true
*/
protected def manualWiringDependencyManagement = false
private def performReRender(sendAll: Boolean) {
lastRenderTime = Helpers.nextNum
if (sendAll) {
cachedFixedRender.reset
}
if (sendAll || !cacheFixedRender) {
clearWiringDependencies()
}
wasLastFullRender = sendAll & hasOuter
deltas = Nil
if (!dontCacheRendering) {
lastRendering = render ++ jsonInCode
}
theSession.updateFunctionMap(S.functionMap, spanId, lastRenderTime)
val rendered: AnswerRender =
AnswerRender(new XmlOrJsCmd(spanId, lastRendering, buildSpan _, notices toList),
this, lastRenderTime, sendAll)
clearNotices
listeners.foreach(_._2(rendered))
listeners = Nil
}
def unWatch = partialUpdate(Call("liftComet.lift_unlistWatch", uniqueId))
/**
* Poke the CometActor and cause it to do a partial update Noop which
* will have the effect of causing the component to redisplay any
* Wiring elements on the component.
* This method is Actor-safe and may be called from any thread, not
* just the Actor's message handler thread.
*/
override def poke(): Unit = {
if (running) {
partialUpdate(Noop)
}
}
/**
* Perform a partial update of the comet component based
* on the JsCmd. This means that the JsCmd will be sent to
* all of the currently listening browser tabs. This is the
* preferred method over reRender to update the component
*/
protected def partialUpdate(cmd: => JsCmd) {
this ! PartialUpdateMsg(() => cmd)
}
protected def startQuestion(what: Any) {}
/**
* This method will be called after the Actor has started. Do any setup here.
* DO NOT do initialization in the constructor or in initCometActor... do it here.
*/
protected def localSetup(): Unit = {}
/**
* Comet Actors live outside the HTTP request/response cycle.
* However, it may be useful to know what Request led to the
* creation of the CometActor. You can override this method
* and capture the initial Req object. Note that keeping a reference
* to the Req may lead to memory retention issues if the Req contains
* large message bodies, etc. It's optimal to capture the path
* or capture any request parameters that you care about rather
* the keeping the whole Req reference.
*/
protected def captureInitialReq(initialReq: Box[Req]) {}
private def _localShutdown() {
localShutdown()
clearNotices
listeners = Nil
askingWho = Empty
whosAsking = Empty
deltas = Nil
jsonHandlerChain = Map.empty
_running = false
_shutDownAt = millis
}
/**
* This method will be called as part of the shut-down of the actor. Release any resources here.
*/
protected def localShutdown(): Unit = {}
/**
* Compose the Message Handler function. By default,
* composes highPriority orElse mediumePriority orElse internalHandler orElse
* lowPriority orElse internalHandler. But you can change how
* the handler works if doing stuff in highPriority, mediumPriority and
* lowPriority is not enough
*/
protected def composeFunction: PartialFunction[Any, Unit] = composeFunction_i
private def composeFunction_i: PartialFunction[Any, Unit] = {
// if we're no longer running don't pass messages to the other handlers
// just pass them to our handlers
if (!_running && (millis - 20000L) > _shutDownAt)
_mediumPriority orElse _lowPriority
else
highPriority orElse mediumPriority orElse
_mediumPriority orElse lowPriority orElse _lowPriority
}
/**
* A helper for binding which uses the defaultHtml property.
*/
def bind(prefix: String, vals: BindParam*): NodeSeq = bind(prefix, _defaultHtml, vals: _*)
/**
* A helper for binding which uses the defaultHtml property and the
* default prefix.
*/
def bind(vals: BindParam*): NodeSeq = bind(_defaultPrefix, vals: _*)
/**
* Ask another CometActor a question. That other CometActor will
* take over the screen real estate until the question is answered.
*/
protected def ask(who: LiftCometActor, what: Any)(answerWith: Any => Unit) {
who.callInitCometActor(theSession, Full(who.uniqueId), name, defaultHtml, attributes)
theSession.addCometActor(who)
// who.link(this)
who ! PerformSetupComet2(Empty)
askingWho = Full(who)
this.answerWith = Full(answerWith)
who ! AskQuestion(what, this, listeners)
// this ! AskRender
}
protected def answer(answer: Any) {
whosAsking.foreach(_ !? AnswerQuestion(answer, listeners))
whosAsking = Empty
performReRender(false)
}
/**
* Convert a NodeSeq => NodeSeq to a RenderOut. The render method
* returns a RenderOut. This method implicitly (in Scala) or explicitly
* (in Java) will convert a NodeSeq => NodeSeq to a RenderOut. This
* is helpful if you use Lift's CSS Seletor Transforms to define
* rendering.
*/
protected implicit def nsToNsFuncToRenderOut(f: NodeSeq => NodeSeq) =
new RenderOut((Box !! defaultHtml).map(f), internalFixedRender, if (autoIncludeJsonCode) Full(jsonToIncludeInCode & S.jsToAppend()) else {
S.jsToAppend match {
case Nil => Empty
case x :: Nil => Full(x)
case xs => Full(xs.reduceLeft(_ & _))
}
}, Empty, false)
/**
* Convert a Seq[Node] (the superclass of NodeSeq) to a RenderOut.
* The render method
* returns a RenderOut. This method implicitly (in Scala) or explicitly
* (in Java) will convert a NodeSeq to a RenderOut. This
* is helpful if you return a NodeSeq from your render method.
*/
protected implicit def arrayToRenderOut(in: Seq[Node]): RenderOut = new RenderOut(Full(in: NodeSeq), internalFixedRender, if (autoIncludeJsonCode) Full(jsonToIncludeInCode & S.jsToAppend()) else {
S.jsToAppend match {
case Nil => Empty
case x :: Nil => Full(x)
case xs => Full(xs.reduceLeft(_ & _))
}
}, Empty, false)
protected implicit def jsToXmlOrJsCmd(in: JsCmd): RenderOut = new RenderOut(Empty, internalFixedRender, if (autoIncludeJsonCode) Full(in & jsonToIncludeInCode & S.jsToAppend()) else Full(in & S.jsToAppend()), Empty, false)
implicit def pairToPair(in: (String, Any)): (String, NodeSeq) = (in._1, Text(in._2 match {case null => "null" case s => s.toString}))
implicit def nodeSeqToFull(in: NodeSeq): Box[NodeSeq] = Full(in)
implicit def elemToFull(in: Elem): Box[NodeSeq] = Full(in)
/**
* Similar with S.error
*/
def error(n: String) {error(Text(n))}
/**
* Similar with S.error
*/
def error(n: NodeSeq) {notices += ((NoticeType.Error, n, Empty))}
/**
* Similar with S.error
*/
def error(id: String, n: NodeSeq) {notices += ((NoticeType.Error, n, Full(id)))}
/**
* Similar with S.error
*/
def error(id: String, n: String) {error(id, Text(n))}
/**
* Similar with S.notice
*/
def notice(n: String) {notice(Text(n))}
/**
* Similar with S.notice
*/
def notice(n: NodeSeq) {notices += ((NoticeType.Notice, n, Empty))}
/**
* Similar with S.notice
*/
def notice(id: String, n: NodeSeq) {notices += ((NoticeType.Notice, n, Full(id)))}
/**
* Similar with S.notice
*/
def notice(id: String, n: String) {notice(id, Text(n))}
/**
* Similar with S.warning
*/
def warning(n: String) {warning(Text(n))}
/**
* Similar with S.warning
*/
def warning(n: NodeSeq) {notices += ((NoticeType.Warning, n, Empty))}
/**
* Similar with S.warning
*/
def warning(id: String, n: NodeSeq) {notices += ((NoticeType.Warning, n, Full(id)))}
/**
* Similar with S.warning
*/
def warning(id: String, n: String) {warning(id, Text(n))}
private def clearNotices {notices clear}
}
abstract class Delta(val when: Long) {
def js: JsCmd
val timestamp = millis
}
case class JsDelta(override val when: Long, js: JsCmd) extends Delta(when)
sealed abstract class CometMessage
/**
* Impersonates the actual comet response content
*/
private[http] class XmlOrJsCmd(val id: String,
_xml: Box[NodeSeq],
_fixedXhtml: Box[NodeSeq],
val javaScript: Box[JsCmd],
val destroy: Box[JsCmd],
spanFunc: (Long, NodeSeq) => NodeSeq,
ignoreHtmlOnJs: Boolean,
notices: List[(NoticeType.Value, NodeSeq, Box[String])]) {
def this(id: String, ro: RenderOut, spanFunc: (Long, NodeSeq) => NodeSeq, notices: List[(NoticeType.Value, NodeSeq, Box[String])]) =
this (id, ro.xhtml, ro.fixedXhtml, ro.script, ro.destroyScript, spanFunc, ro.ignoreHtmlOnJs, notices)
val xml = _xml.flatMap(content => S.session.map(s => s.processSurroundAndInclude("JS SetHTML id: " + id, content)))
val fixedXhtml = _fixedXhtml.flatMap(content => S.session.map(s => s.processSurroundAndInclude("JS SetHTML id: " + id, content)))
/**
* Returns the JsCmd that will be sent to client
*/
def toJavaScript(session: LiftSession, displayAll: Boolean): JsCmd = {
var ret: JsCmd = JsCmds.JsTry(JsCmds.Run("destroy_" + id + "();"), false) &
((if (ignoreHtmlOnJs) Empty else xml, javaScript, displayAll) match {
case (Full(xml), Full(js), false) => LiftRules.jsArtifacts.setHtml(id, Helpers.stripHead(xml)) & JsCmds.JsTry(js, false)
case (Full(xml), _, false) => LiftRules.jsArtifacts.setHtml(id, Helpers.stripHead(xml))
case (Full(xml), Full(js), true) => LiftRules.jsArtifacts.setHtml(id + "_outer", (
spanFunc(0, Helpers.stripHead(xml)) ++ fixedXhtml.openOr(Text("")))) & JsCmds.JsTry(js, false)
case (Full(xml), _, true) => LiftRules.jsArtifacts.setHtml(id + "_outer", (
spanFunc(0, Helpers.stripHead(xml)) ++ fixedXhtml.openOr(Text(""))))
case (_, Full(js), _) => js
case _ => JsCmds.Noop
}) & JsCmds.JsTry(JsCmds.Run("destroy_" + id + " = function() {" + (destroy.openOr(JsCmds.Noop).toJsCmd) + "};"), false)
S.appendNotices(notices)
ret = S.noticesToJsCmd & ret
ret
}
def inSpan: NodeSeq = xml.openOr(Text("")) ++ javaScript.map(s => Script(s)).openOr(Text(""))
def outSpan: NodeSeq = Script(Run("var destroy_" + id + " = function() {" + (destroy.openOr(JsCmds.Noop).toJsCmd) + "}")) ++
fixedXhtml.openOr(Text(""))
}
/**
* Update the comet XML on each page reload in dev mode
*/
case class UpdateDefaultXml(xml: NodeSeq) extends CometMessage
case class PartialUpdateMsg(cmd: () => JsCmd) extends CometMessage
case object AskRender extends CometMessage
case class AnswerRender(response: XmlOrJsCmd, who: LiftCometActor, when: Long, displayAll: Boolean) extends CometMessage
case class PerformSetupComet2(initialReq: Box[Req]) extends CometMessage
case object ShutdownIfPastLifespan extends CometMessage
case class AskQuestion(what: Any, who: LiftCometActor, listeners: List[(ListenerId, AnswerRender => Unit)]) extends CometMessage
case class AnswerQuestion(what: Any, listeners: List[(ListenerId, AnswerRender => Unit)]) extends CometMessage
case class Listen(when: Long, uniqueId: ListenerId, action: AnswerRender => Unit) extends CometMessage
case class Unlisten(uniqueId: ListenerId) extends CometMessage
case class ActionMessageSet(msg: List[() => Any], req: Req) extends CometMessage
case class ReRender(doAll: Boolean) extends CometMessage
case class ListenerId(id: Long)
case class Error(id: Box[String], msg: NodeSeq) extends CometMessage
case class Warning(id: Box[String], msg: NodeSeq) extends CometMessage
case class Notice(id: Box[String], msg: NodeSeq) extends CometMessage
case object ClearNotices extends CometMessage
object Error {
def apply(node: NodeSeq): Error = Error(Empty, node)
def apply(node: String): Error = Error(Empty, Text(node))
def apply(id: String, node: String): Error = Error(Full(id), Text(node))
def apply(id: String, node: NodeSeq): Error = Error(Full(id), node)
}
object Warning {
def apply(node: NodeSeq): Warning = Warning(Empty, node)
def apply(node: String): Warning = Warning(Empty, Text(node))
def apply(id: String, node: String): Warning = Warning(Full(id), Text(node))
def apply(id: String, node: NodeSeq): Warning = Warning(Full(id), node)
}
object Notice {
def apply(node: NodeSeq): Notice = Notice(Empty, node)
def apply(node: String): Notice = Notice(Empty, Text(node))
def apply(id: String, node: String): Notice = Notice(Full(id), Text(node))
def apply(id: String, node: NodeSeq): Notice = Notice(Full(id), node)
}
/**
* The RenderOut case class contains the rendering for the CometActor.
* Because of the implicit conversions, RenderOut can come from
* <br/>
* @param xhtml is the "normal" render body
* @param fixedXhtml is the "fixed" part of the body. This is ignored unless reRender(true)
* @param script is the script to be executed on render. This is where you want to put your script
* @param destroyScript is executed when the comet widget is redrawn ( e.g., if you register drag or mouse-over or some events, you unregister them here so the page doesn't leak resources.)
* @param ignoreHtmlOnJs -- if the reason for sending the render is a Comet update, ignore the xhtml part and just run the JS commands. This is useful in IE when you need to redraw the stuff inside <table>... just doing innerHtml on | Other Lift Framework examples (source code examples)Here is a short list of links related to this Lift Framework CometActor.scala source code file: |
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