Subject: I have a stream (actually combined stream from Bacon.interval and buttons clicks EventStreams) wich fires ajax request and solve task of manual and automatic data refresh.
Problem: After manual events (buttons clicks) I need reset timer because two immediate updates looks ugly.
My solution: I've created my own Bacon.interval implementation where event polls can be reseted http://jsfiddle.net/cvvkxveq/1/:
Bacon.dynInterval = function(time,resetter){
if(!time) return Bacon.once(new Bacon.Error("Invalid args"));
var ivId, lastTime = Date.now();
return time < 1 ? Bacon.once(new Bacon.Error("Invalid time")) : Bacon.fromBinder(function(sink) {
function setUpInterval(){
if(ivId) clearInterval(ivId);
ivId = setInterval(function(){
var n = Date.now();
var tdx = n - lastTime;
lastTime = n;
sink(new Bacon.Next(tdx));
},time);
}
setUpInterval();
if(resetter) resetter.onValue(setUpInterval);
return function() {
clearInterval(ivId);
sink(new Bacon.End())
}
})
}
Question: Is such behaivour can be done without custom event stream?
Update (thanks #raimohanska's answer) basing on #raimohanska's answer I've also converded my ouUiE event sream (manualTriggerE) to property with initial value to accomplish immediate updates starts.
var quotesService = Bacon.constant({url:"quotes.php"});
var onUiE = $("#next_stock, #prev_stock, #refresh_quotes").clickE().map(".currentTarget.id");
var onUiP = onUiE.toProperty("");
var periodicUpdateE = onUiP.flatMapLatest(function(){ return Bacon.interval(3000)});
var manualPlusPeriodicP = onUiP.toEventStream().merge(periodicUpdateE);
var quotesStream = quotesService.sampledBy(manualPlusPeriodicP).ajax();
If you have a stream manualTriggerE, you can add periodic updates that are reseted on each manual trigger like this:
let periodicUpdateE = manualTriggerE.flatMapLatest(() => Bacon.interval(1000))
let manualPlusPeriodicE = manualTrigger.merge(periodicUpdateE)
The trick is flatMapLatest: it restarts the periodic updates whenever a manual trigger occurs.
Related
I wanted the scene load 5 different movie clips (named B1-B5). Each movie clip is placed on a specific x and y. Each movie clip grows/shrinks on roll over/roll out....
I got the code working by typing everything out and duplicating each section per time but it's messy and I'd like to clean up the code by getting a loop to do it (if it's possible?).
This is the code that works but I'd have to duplicate it per movie clip (changing the obvious bits)...
var scene1:MovieClip = new B1();
addChild(scene1);
scene1.x = 170.30;
scene1.y = 231.15;
scene1.addEventListener(MouseEvent.MOUSE_OVER, onRollOverEvent1);
scene1.addEventListener(MouseEvent.MOUSE_OUT, onRollOutEvent1);
function onRollOverEvent1(e:MouseEvent) {
scene1.width=25.9;
scene1.height=25;
}
function onRollOutEvent1(e:MouseEvent) {
scene1.width = 20.9;
scene1.height = 20;
}
Below is what I've tried out but have been stuck for a good while...
for (var i:int=1; i<5; i++){
var scene[i]:MovieClip = new "B"+i();
addChild("scene"+i);
//var scene[i]:MovieClip = new B[i]();
scene[i].addEventListener(MouseEvent.MOUSE_OVER, onRollOverEvent);
scene[i].addEventListener(MouseEvent.MOUSE_OUT, onRollOutEvent)
function onRollOverEvent(e:MouseEvent) {
scene[i].width=25.9;
scene[i].height=25;
}
function onRollOutEvent(e:MouseEvent) {
scene[i].width = 20.9;
scene[i].height = 20;
}
}
scene1.x = 170.30;
scene1.y = 231.15;
scene2.x = 284.30;
scene2.y = 250.75;
scene3.x = 377.30;
scene3.y = 280.15;
scene4.x = 444.30;
scene4.y = 321.15;
scene5.x = 196.30;
scene5.y = 172.15;
First, lets go through your mistakes.
new "B"+i();
At the very best that translates to calling a number i as function and adding the result to "B" as a String. But even new "B1"() is not the same as new B1(). There is, in fact, a method getDefinitionByName(..) that allows to address a class via its name, but I don't recommend to use it because it is advanced topic.
var scene[i]:MovieClip
You just cannot define variables scene1, scene2, etc this way. The closest thing you can actually devise is the square bracket notation: this["scene" + i] = ....
addChild("scene"+i);
The argument must be a DisplayObject instance, not a String.
for (...)
{
...
function onRollOverEvent(e:MouseEvent)
...
}
Do not define functions inside other functions or loops.
scene[i].width = 20.9;
scene[i].height = 20;
By the end of your loop i will be equal to 5, so, what do you think such a record will address?
Then, the solution.
When you come to scaling your working solution to multiple instances, you are to go algorithmic. Loops and Arrays are your friends.
// Lets devise a list of classes and (x,y) coordinates.
var Designs:Array = [
null, // the 0-th element
{id:B1, x:170, y:230},
{id:B2, x:285, y:250},
];
for (var i:int = 1; i < Design.length; i++)
{
// Retrieve a record for the future object.
var aDesign:Object = Designs[i];
// Get a reference to the object's class.
var aClass:Class = aDesign.id;
// Create the object. Yes, you CAN omit () with
// the "new" operator if there are no mandatory arguments.
var aThing:Movieclip = new aClass;
// Set coordinates from the design record.
aThing.x = aDesign.x;
aThing.y = aDesign.y;
// Add to the display list.
addChild(aThing);
// Subscribe the event handlers.
aThing.addEventListener(MouseEvent.MOUSE_OVER, onOver);
aThing.addEventListener(MouseEvent.MOUSE_OUT, onOut);
// Save the object's reference for the later use.
// If you'd need to address, say, 3rd object,
// you do it as following:
// Designs[3].instance
aDesign.instance = aThing;
}
function onOver(e:MouseEvent):void
{
// You subscribed all of the objects to this one event handler.
// This is the correct way to learn, which one of the objects
// is under the mouse and is dispatching the said event.
var aThing:MovieClip = e.currentTarget as MovieClip;
// Change the object's size.
aThing.width = 26;
aThing.height = 25;
}
function onOut(e:MouseEvent):void
{
// Get the source of the dispatched event.
var aThing:MovieClip = e.currentTarget as MovieClip;
// Change the object's size.
aThing.width = 21;
aThing.height = 20;
}
I have an interface that calls a script for spreadsheet creation using data taken from other spreadsheet. I want the interface to update its labels at runtime in order to give visual feedback to the user and let him know the script is running and it's not stuck. When I try to update the label I put in the interface, it doesn't update the first time, but updates correctly after myFunction() reaches its end. Which means I can see the message "Creation Completed", but the message "Creating file..." is never shown. Also, the button buttonCompile is never disabled so it seems that the instructions before myFunction() are not executed at all. How can I get the labels updated and the button disabled before myFunction() starts executing? (I already double-checked variable references)
function doGet() {
var app = UiApp.createApplication();
app.add(app.loadComponent("File creation"));
var buttonCreate = app.getElementById('createBtn');
var handlerCrea = app.createServerHandler('createClickHandler');
buttonCreate.addClickHandler(handlerCreate);
return app;
}
function createClickHandler(e) {
var app = UiApp.getActiveApplication();
var label = app.getElementById('createLbl');
label.setText("Creating file...");
var buttonCompile = app.getElementById('compileBtn');
buttonCompile.setEnabled(false);
myFunction();
label.setText("Creation completed.");
buttonCompile.setEnabled(true);
app.close();
return app;
}
The cause of this behavior is that the GUI is updated only after leaving a handler. A workaround is to use two handlers. The 1st one sets the label text to Creating file... and disables the button, the 2nd one executes the myFunction function, changes the text to Creation completed, and eanbles the button. Here is an example. It disables/enables the button and the worker handler simply waits 5 seconds.
function doGet(e) {
var app = UiApp.createApplication();
var container = app.createHorizontalPanel().setId('container');
var btnPerformance = app.createButton("Performance Demo").setId('btnPerformance');
var handlerPerformance = app.createServerHandler('onBtnPerformanceClick');
var handlerWait = app.createServerHandler('onWait');
btnPerformance.addClickHandler(handlerPerformance);
btnPerformance.addClickHandler(handlerWait);
container.add(btnPerformance);
app.add(container);
return app;
}
function enableControls(enable) {
var lstControls = [ 'btnPerformance' ];
var app = UiApp.getActiveApplication();
for (var i = 0; i < lstControls.length; i++) {
var ctl = app.getElementById(lstControls[i]);
ctl.setEnabled(enable);
}
}
function onWait(e) {
enableControls(false);
return UiApp.getActiveApplication();
}
function onBtnPerformanceClick(e) {
Utilities.sleep(5000);
enableControls(true);
return UiApp.getActiveApplication();
}
I have decent large data set of around 1100 records. This data set is mapped to an observable array which is then bound to a view. Since these records are updated frequently, the observable array is updated every time using the ko.mapping.fromJS helper.
This particular command takes around 40s to process all the rows. The user interface just locks for that period of time.
Here is the code -
var transactionList = ko.mapping.fromJS([]);
//Getting the latest transactions which are around 1100 in number;
var data = storage.transactions();
//Mapping the data to the observable array, which takes around 40s
ko.mapping.fromJS(data,transactionList)
Is there a workaround for this? Or should I just opt of web workers to improve performances?
Knockout.viewmodel is a replacement for knockout.mapping that is significantly faster at creating viewmodels for large object arrays like this. You should notice a significant performance increase.
http://coderenaissance.github.com/knockout.viewmodel/
I have also thought of a workaround as follows, this uses less amount of code-
var transactionList = ko.mapping.fromJS([]);
//Getting the latest transactions which are around 1100 in number;
var data = storage.transactions();
//Mapping the data to the observable array, which takes around 40s
// Instead of - ko.mapping.fromJS(data,transactionList)
var i = 0;
//clear the list completely first
transactionList.destroyAll();
//Set an interval of 0 and keep pushing the content to the list one by one.
var interval = setInterval(function () {if (i == data.length - 1 ) {
clearInterval(interval);}
transactionList.push(ko.mapping.fromJS(data[i++]));
}, 0);
I had the same problem with mapping plugin. Knockout team says that mapping plugin is not intended to work with large arrays. If you have to load such big data to the page then likely you have improper design of the system.
The best way to fix this is to use server pagination instead of loading all the data on page load. If you don't want to change design of your application there are some workarounds which maybe help you:
Map your array manually:
var data = storage.transactions();
var mappedData = ko.utils.arrayMap(data , function(item){
return ko.mapping.fromJS(item);
});
var transactionList = ko.observableArray(mappedData);
Map array asynchronously. I have written a function that processes array by portions in another thread and reports progress to the user:
function processArrayAsync(array, itemFunc, afterStepFunc, finishFunc) {
var itemsPerStep = 20;
var processor = new function () {
var self = this;
self.array = array;
self.processedCount = 0;
self.itemFunc = itemFunc;
self.afterStepFunc = afterStepFunc;
self.finishFunc = finishFunc;
self.step = function () {
var tillCount = Math.min(self.processedCount + itemsPerStep, self.array.length);
for (; self.processedCount < tillCount; self.processedCount++) {
self.itemFunc(self.array[self.processedCount], self.processedCount);
}
self.afterStepFunc(self.processedCount);
if (self.processedCount < self.array.length - 1)
setTimeout(self.step, 1);
else
self.finishFunc();
};
};
processor.step();
};
Your code:
var data = storage.transactions();
var transactionList = ko.observableArray([]);
processArrayAsync(data,
function (item) { // Step function
var transaction = ko.mapping.fromJS(item);
transactionList().push(transaction);
},
function (processedCount) {
var percent = Math.ceil(processedCount * 100 / data.length);
// Show progress to the user.
ShowMessage(percent);
},
function () { // Final function
// This function will fire when all data are mapped. Do some work (i.e. Apply bindings).
});
Also you can try alternative mapping library: knockout.wrap. It should be faster than mapping plugin.
I have chosen the second option.
Mapping is not magic. In most of the cases this simple recursive function can be sufficient:
function MyMapJS(a_what, a_path)
{
a_path = a_path || [];
if (a_what != null && a_what.constructor == Object)
{
var result = {};
for (var key in a_what)
result[key] = MyMapJS(a_what[key], a_path.concat(key));
return result;
}
if (a_what != null && a_what.constructor == Array)
{
var result = ko.observableArray();
for (var index in a_what)
result.push(MyMapJS(a_what[index], a_path.concat(index)));
return result;
}
// Write your condition here:
switch (a_path[a_path.length-1])
{
case 'mapThisProperty':
case 'andAlsoThisOne':
result = ko.observable(a_what);
break;
default:
result = a_what;
break;
}
return result;
}
The code above makes observables from the mapThisProperty and andAlsoThisOne properties at any level of the object hierarchy; other properties are left constant. You can express more complex conditions using a_path.length for the level (depth) the value is at, or using more elements of a_path. For example:
if (a_path.length >= 2
&& a_path[a_path.length-1] == 'mapThisProperty'
&& a_path[a_path.length-2] == 'insideThisProperty')
result = ko.observable(a_what);
You can use typeOf a_what in the condition, e.g. to make all strings observable.
You can ignore some properties, and insert new ones at certain levels.
Or, you can even omit a_path. Etc.
The advantages are:
Customizable (more easily than knockout.mapping).
Short enough to copy-paste it and write individual mappings for different objects if needed.
Smaller code, knockout.mapping-latest.js is not included into your page.
Should be faster as it does only what is absolutely necessary.
The aim is to remove only the last row at any time and only by the last remove button.
There is a user interface which building up as a multiplication of the same row. The number of rows are controlled by 'Add' & 'Remove' buttons which are also elements of the row. The problem is that the hidden widgets - that are applied for each row to distinguish the instances by storing their row numbers - are storing the very same number which is the last one. Except the first (0) hidden widget which stores the proper number (0). Where am I missing the point? How should this be resolved?
As per the remove buttons have two different purposes (not detailed here), we use a cacheService to distinguish the last row from all the others. Only the last row should be removed at any time.
var cache = CacheService.getPrivateCache();
we clear the cache and create the first instance
function doGet() {
var app = UiApp.createApplication();
app.add(app.createVerticalPanel().setId('mainContainer'));
cache.removeAll([]);
ui(0);
cache.put('numberOfInstances',0);
return app; }
each instance is held by a horizontal panel which contains the mentioned hidden widget, a label which informs about the instance number, and the Add & Remove buttons.
function ui(instance) {
var app = UiApp.getActiveApplication();
var eventContainer = app.createHorizontalPanel()
.setId('eventContainer' + instance);
var instanceContainer = app.createHidden('instanceContainer',instance);
var showInstance = app.createLabel(instance)
.setId('showInstance' + instance);
var addButton = app.createButton('Add')
.setId('add' + instance)
.addClickHandler(app.createClientHandler()
.forEventSource().setEnabled(false)) //avoiding multiple click during server response
.addClickHandler(app.createServerHandler('add')
.addCallbackElement(instanceContainer));
var removeButton = app.createButton('X')
.addClickHandler(app.createServerHandler('remove')
.addCallbackElement(instanceContainer));
app.getElementById('mainContainer')
.add(eventContainer
.add(instanceContainer)
.add(showInstance)
.add(addButton)
.add(removeButton));
return app; }
and the event handling...
function add(inst) {
var app = UiApp.getActiveApplication();
var instance = Number(inst.parameter.instanceContainer);
ui(instance+1);
cache.put('numberOfInstances',instance+1);
return app; }
function remove(inst) {
var app = UiApp.getActiveApplication();
var instance = Number(inst.parameter.instanceContainer);
var numberOfInstances = cache.get('numberOfInstances')
if( (instance != 0) && (instance = numberOfInstances) ) {
app.getElementById('mainContainer').remove(app.getElementById('eventContainer' + instance));
cache.put('numberOfInstances',instance-1);
app.getElementById('add' + (instance-1)).setEnabled(true); } //avoiding multiple click during server response
return app; }
The aim is to remove only the last row at any time and only by the last remove button.
Many Thanks.
Why don't you simply use a clientHandler just as you did on the 'add' button? You could target the preceding 'remove' button and disable it each time you create a new one and change /update each time you remove one row.
EDIT : I can suggest you something, feel free to have a look, I changed a bit the approach but it is working and I hope you'll find it at least interesting ;-)
Link to the online test
function doGet() {
var app = UiApp.createApplication();
var counter = app.createHidden().setName('counter').setId('counter').setValue('1');
var mainContainer = app.createVerticalPanel().setId('mainContainer')
app.add(mainContainer.add(counter));
var event1Container = app.createHorizontalPanel()
var showInstance = app.createLabel('1')
var addButton = app.createButton('Add')
.setId('add1')
.addClickHandler(app.createClientHandler()
.forEventSource().setEnabled(false)) //avoiding multiple click during server response
.addClickHandler(app.createServerHandler('add')
.addCallbackElement(mainContainer));
var removeButton = app.createButton('X')
.setId('remove1')
.addClickHandler(app.createServerHandler('remove')
.addCallbackElement(mainContainer));
mainContainer.add(event1Container
.add(showInstance)
.add(addButton)
.add(removeButton));
return app; }
function add(inst) {
var app = UiApp.getActiveApplication();
var hiddenVal =inst.parameter.counter;
var counterVal = Number(hiddenVal);
var mainContainer = app.getElementById('mainContainer')
var counter = app.getElementById('counter')
++ counterVal
counter.setValue(counterVal.toString())
var eventContainer = app.createHorizontalPanel().setId('eventContainer'+counterVal)
var showInstance = app.createLabel(counterVal.toString())
var addButton = app.createButton('Add')
.setId('add'+counterVal)
.addClickHandler(app.createClientHandler()
.forEventSource().setEnabled(false)) //avoiding multiple click during server response
.addClickHandler(app.createServerHandler('add')
.addCallbackElement(mainContainer));
var removeButton = app.createButton('X')
.setId('remove'+counterVal)
.addClickHandler(app.createServerHandler('remove')
.addCallbackElement(mainContainer));
app.add(eventContainer
.add(showInstance)
.add(addButton)
.add(removeButton));
if(counterVal>1){app.getElementById('remove'+(counterVal-1)).setEnabled(false)}
return app; }
function remove(inst) {
var app = UiApp.getActiveApplication();
var counterVal = Number(inst.parameter.counter);
var counter = app.getElementById('counter')
if(counterVal ==1) {return app}
var maincontainer = app.getElementById('mainContainer')
app.getElementById('eventContainer' + counterVal).setVisible(false)
--counterVal
counter.setValue(counterVal.toString())
app.getElementById('add'+counterVal).setEnabled(true)
app.getElementById('remove'+counterVal).setEnabled(true)
return app;
}
NOTE : I didn't make use of .remove(widget) since this is a fairly new method and I don't know exactly how it works... I'll test it later. Until then I used setVisible(false) instead, sorry about that :-)
Note 2 : I didn't use the cache since the hidden widget is sufficient to keep track of what is going on... if you needed it for something else then you could always add it back .
this is what i'm trying to accomplish;
With a click on a movieclip (cannon_mc)
a shot is being fired (ball_mc)
The longer mouse is down, the speed of wich the ball is fired with should increase.
My question to you is;
What is the most efficient way to accomplish this?
With a timer or something like this;
var isMouseDown:Boolean = false;
var speed= 10;
myCannon.addEventListener(MouseEvent.MOUSE_DOWN,buttonPressed);
function buttonPressed(event:MouseEvent){
//trace("down");
isMouseDown == true;
if(isMouseDown == false)
{
speed == +1
}
}
The MOUSE_DOWN event is only fired once. To get the effect you want you need the combo of MOUSE_DOWN and MOUSE_UP Event Handlers.
You can set a variable to true in the MOUSE_DOWN event alongwith the current timestamp from flash.utils.getTimer()
Then on MOUSE_UP, if the variable you set in MOUSE_DOWN is true, you compute the time elapsed and set the power accordingly.
Example:
var isMouseDown:Boolean = false;
var mouseDownBegin:int;
var speed = 10;
var speed_inc = 2; // give it in per second
var speed_max = 100; // max speed possible
// add event handlers
myCannon.addEventListener(MouseEvent.MOUSE_DOWN, buttonPressed);
myCannon.addEventListener(MouseEvent.MOUSE_UP, buttonReleased);
function buttonPressed(event:MouseEvent){
isMouseDown = true;
mouseDownBegin = flash.utils.getTimer();
}
function buttonReleased(event:MouseEvent){
if(isMouseDown == true){
// get time between press and release
var timeElapsed = flash.utils.getTimer() - mouseDownBegin;
// reset isMouseDown
isMouseDown = false;
// compute speed
speed += int(Math.floor(speed_inc * (timeElapsed / 1000.0)));
speed = Math.min(speed, speed_max);
// code to fire ball with new speed
// .......
}
}
You can also add an ENTER_FRAME event and animate a power gauge or something for visual effect
Update
As pointed to by The_asMan, MOUSE_UP event will not fire if the mouse is dragged and released Outside the stage. To handle this case add and event listener for MOUSE_LEAVE event with the callback as the copy of buttonReleased function but which takes an Event object:
function buttonReleasedOutsideStage(event:Event){
if(isMouseDown == true){
// get time between press and release
var timeElapsed = flash.utils.getTimer() - mouseDownBegin;
// reset isMouseDown
isMouseDown = false;
// compute speed
speed += int(Math.floor(speed_inc * (timeElapsed / 1000.0)));
speed = Math.min(speed, speed_max);
// code to fire ball with new speed
// .......
}
}
stage.addEventListener(Event.MOUSE_LEAVE, buttonReleasedOutsideStage);
(in very short pseudocode)
Write some event handlers:
onMouseDown: sets flag _mouseDown, set power to zero
onFrame: if (_mouseDown) power++;
onMouseUp: clears flag _mouseDown and fires ball with accumulated power
Framerate independent version:
onMouseDown: _loadStart = getTimer(); _mouseDown = true; _power = 0;
onFrame: if (_mouseDown) delta = getTimer() - _loadStart; _power += delta;
onMouseUp: shot the ball with _power, _mouseDown = false;