listening for viewstack change event - apache-flex

I have a piece of software I'm working on that is using a viewstack with 3 canvases. With the change event I need to look for index 2 which is the last canvas when it changes to this canvas I need it to grab data from inputs from the previous two canvases.
Within the viewstack events I've assigned the function change() to the event childIndexChange.
Here is the method:
private function change():void
{
Alert.show(customerViewStack.selectedIndex.toString());
}
eventually this method will look something like this:
public function change():void
{
if(customerViewStack.selectedIndex == 2)
{
rCID.text = cidTxt.text;
rCNAME.text = nameTxt.text;
rCACCTN.text = acctNumTxt.text;
rCACCTR.text = acctRep.text;
rCWEB.text = website.text;
rCACTIVE.text = active.text;
rCSTREET.text = cStreet.text + " "+ cSuite.text;
rCCSZ.text = cCity.text + ", " + cState.text + " " + cZipcode.text;
rCPHN.text = cPhone.text;
rCAPHN.text = cPhone0.text;
rCFAX.text = cFax.text;
}
}
to alternate through my views im using this approach with buttons actually inside the canvases:
customerViewStack.selectedChild=cAddress
anyway the problem is the event doesn't seem to be firing my change function because no alert is coming up also the way I'm doing this is probably quite naive so if you have any suggestions please I'm open.

I've taken another approach I'm going to bypass "deferred instantiation" and turn the cereationPolicy to all. The view before the last I will set values from there then transition over.
However if anyone has any thoughts or criticism please feel free.

The change event will fire when the view is changed, so simply subscribing to this event instead of childIndexChange should solve the problem.

Related

Creating Flex Elements Server Side

i wonder if it is possible to pre-configurate Flex Elements on the Server. I have the Problem with a custom ItemRenderer which turns out to be very slow. It would be very cool to pre-process such an element on the server instead in the clients browser... somehow? Maybe it is possible to produce the MXML dynamically on the server for that.
This is it basically. I create a Label for each data entry in an array list. This entry is added to a BorderContainer and this goes to the containing element as a whole here. Sometimes i add 200 - 300 items this way which is costing very high computing cost at client side. So i wonderd if i could just pass this as a whole dynamic mxml element to the client.
override public function set data(value:Object):void {
_data = value as WordResultObject;
var data:WordResultObject = _data as WordResultObject;
this.removeAllElements();
if(_data!=null)
{
_l.text = data.wordform;
_l.setStyle("fontSize", data.fontSize);
_l.setStyle("color", data.color);
_l.toolTip = "Frequency: " + data.freq;
if(data.date != null)
{
_l.toolTip += "\nDate: " + AppUtils.TimeString(data.date as Date);
_l.addClickEvent(data.id as int, data.date as Date);
}
_border.addElement(_l);
this.addElement(_border);
}
}
Thank you
Andreas
I wonder if it is possible to
pre-configurate Flex Elements on the
Server.
Not that I know of. Perhaps if you go back to Flex 1 / 1.5 which was primarily a server based platform. I do not expect rolling your code back to an "old" server would improve efficiency at all, though. How would you expect this work? What benefit are you expecting to receive.
I have the Problem with a custom
ItemRenderer which turns out to be
very slow.
Show your code; and perhaps we can help you with writing your renderer to be more efficient.

Resetting target values in a composite effect

We need to be able to handle a "playable" (play/pause/seek) effect in which the nature of the effect cannot be determined at compile time.
The problem we are running into is resetting the target(s) state after the effect has completed. If we manually drag the seek slider back to the beginning, everything works fine. However, if we set the playheadTime of the composite effect back to 0, the effected targets retain their original value until the playheadTime gets to the correct position to effect the target.
Here is a simplified (as much as I could) test case with view source enabled:
http://www.openbaseinteractive.com/_tmp/PlayableEffectTest/
The problem is demonstrated if you let it play to the end, and then hit the play button to start it over.
What is the best way to go about manually resetting the target values given that the exact nature of the effect is unknown?
Many thanks for your time!
edit
I forgot to mention we are using Flex 4.5 preview release.
Have you tried:
effect.reverse()
More info
http://help.adobe.com/en_US/FlashPlatform/reference/actionscript/3/mx/effects/IEffect.html
http://help.adobe.com/en_US/FlashPlatform/reference/actionscript/3/mx/effects/IEffect.html#reverse()
Well it's a little kludgy, but I was able to accomplish this by calling some internal methods on the effect to capture the start values, then assigned those values to the targets on a reset.
import mx.core.mx_internal;
use namespace mx_internal;
private var _propertyChangesArray:Array;
protected function captureStartValues(effect:Object):void
{
effect.captureStartValues();
_propertyChangesArray = effect.propertyChangesArray;
}
protected function reset(effect:Object):void
{
for each(var change:PropertyChanges in _propertyChangesArray)
{
var target:Object = change.target;
for(var p:String in change.start)
{
if(target.hasOwnProperty(p))
{
var startVal:* = change.start[p];
var endVal:* = target[p];
if(!isNaN(startVal) && startVal != endVal)
{
target[p] = startVal;
}
}
}
}
effect.playheadTime = 0;
}
I don't know if this is the best way to accomplish this, but it seems to be working so far. I am absolutely open to suggestions for a better method.
Cheers!

Is there some way to force 'updatedisplaylist' immediately rather than at later some point

In flex component life cycle, after we make some change in a components property, invalidation methods schedules a call to methods like commitProperties, updateDisplayList, etc for some later time. I need to call the updateDisplayList instantaneously. Is there some direct way to do this.
Currently, both the labels are changed simultaneously after completion of the loop. Instead I need it to work like this, to first render the updated 'myButton1' label then enter the loop and then update myButton2's label. I know, it is elastic race track issue, but isn't there some way to achieve this ?
myButton1.label = 'New Label1' ;
// Some logic to forcibly make the screen reflect it
for (var i:int = 0; i < 500 ; i ++){
//a dummy loop
}
myButton2.label = 'New Label2' ;
You can use myButton1.validateNow() but it's use is discouraged, for you may end up having the same component update itself multiple times on the same frame.
Use validateNow() . But, I would use it sparingly. using invalidateDisplayList() will force updateDisplayList() to run on the next renderer event.
A render event happens on each frame. 24 frames happen each second by default for Flex. Are you sure need to change these values quicker?
I would set the label for myButton1, then put the remaining code into a separate method and call that method using callLater:
private function foo():void {
myButton1.label = 'New Label1';
this.callLater(bar);
}
private function bar():void {
for (var i:int = 0; i < 500 ; i ++){ //a dummy loop
}
myButton2.label = 'New Label2';
}
This way myButton1 will update to show the new label before going into your loop since callLater doesn't call bar until after the event queue is cleared, giving myButton1 a chance to update.
invalidateDisplayList() or valdiateNow() will do it for you however excess of using these will end up memory leaks.

How do I programmatically associate a RadioButton with a RadioButtonGroup in ActionScript3?

I have a UI component that, for various reasons, I have to construct programatically. The component is a table of radio buttons grouped by column.
Right now, I'm constructing the column groups like so:
private function createGroupsForItemList(items: XMLList): void {
for each (var item: XML in items) {
var rbGroup: RadioButtonGroup = new RadioButtonGroup();
groups[item.#level.toString()] = rbGroup;
}
}
I'm trying to associate the RadioButton instances with the column groups like so:
private function createValueControl(item: XML): UIComponent {
var control: RadioButton = new RadioButton();
control.label = "";
control.group = groups[item.#level.toString()];
control.addEventListener(Event.SELECT, updateSelection);
return control;
}
I can see in the debugger that the control has an association to the group:
control.group == groups[item.#level.toString()]
However, I can see equally that the group does not know anything about the control:
group.radioButtons.length == 0
I imagine that this is because the setter for group in RadioButton is a dumb setter; all it does is copy to the variable, which doesn't do the magic that groupName does. However, I can't seem to find the value I should use to set the RadioButton.groupName property correctly.
So, in short, I'm stumped on how to get these bits to talk to each other. How do I do this?
-- EDIT --
It turns out that I can have the groups created and associated simply by setting the groupName property, but I can't get at the group to set up a selection listener; the group is NULL immediately after the setting process, which means that the second line below throws the Flex equivalent of an NPE:
control.groupName = groupNameForLevel(item);
control.group.addEventListener(Event.SELECT, updateSelection);
First instinct is that this issue has to do with invalidateDisplayList and when and how that is called. Of course, since issues related to that function are behind a number of Flex's quirks, I may just be scapegoating.
This is not the answer to your question per se, but it seems like it might actually work as an alternate solution.
RadioButtonGroups will initialize based on a IFlexDisplayObject. This means that you can do something like:
var c:HBox = new HBox();
var rbg:RadioButtonGroup = new RadioButtonGroup( c );
// do stuff with rbg.
c.addChild( new RadioButton() );
The problem is that it may not be the most practical answer, but it has the decided benefit of being a workable solution.
Setting groupName should work.
All I can suggest is to step through the group() getter of the RadioButton component and see where exactly it is failing. Are you programmatically creating the group too? If that's the case, maybe it isn't initialized fully yet.

I want to add items to an ASP.Net combobox using Javascript

I want to add an item to an ASP.Net combobox using Javascript. I can retrieve the ID (No Masterpage). How can I add values to the combobox from Javascript? My present code looks like this.
//Fill the years (counting 100 from the first)
function fillvarYear() {
var dt = $('#txtBDate').val();
dt = dt.toString().substring(6);
var ye = parseInt(dt);
//Loop and add the next 100 years from the birth year to the combo
for (var j = 1; j <= 100; j++) {
ye += 1; //Add one year to the year count
var opt = document.createElement("OPTION");
opt.text = ye;
opt.value = ye;
document.form1.ddlYear.add(opt);
}
}
To see the value on postback:
string selectedValue = Request.Params[combobox.UniqueId]
Remember, changing the values in a combobox with javascript will cause an Event Validation exception to be thrown, and is generally a bad idea, as you'll have to explicitly disabled event validation.
I'd recommend placing the combobox in an update panel, so you can read txtBirthDate on the server and generate the appropriate data. You then won't have to manually preserve state either.
Always remember, ASP.NET controls are nothing "fancy" - they always end up at some point becoming standard HTML elements.
Try checking out this site. It has a pretty nice demo and overview. Take note however that you are altering the data at the client side - this means you will need to do it on each and every request because the ViewState will not be updated.
TBH, you are probably better off just using a HTML control rather than ASP ComboBox..
Can I ask why you are changing items via Javascript? (out of curiosity) :)
I found a possible solution. I don't know why the earlier code didn't work for me, but the line below
document.form1.ddlYear.appendChild(new Option(ye, ye));

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