in Adobe tutorials, they suggest to create a class to handle the events (see below the copy/pasted code, and link to page).
I was wondering if I have to handle all events with the function handleAllEvents, using if statements to check if the target is the one I want, and the event is the one I want.
i.e. if (event.type=="click") && (event.currentTarget == "myId")
Should I have a list of ifs (for each target and each event type ?)
thanks
// events/MyStaticEventHandler.as
package { // Empty package.
import flash.events.Event;
import mx.controls.Alert;
public class MyStaticEventHandler {
public function MyStaticEventHandler() {
// Empty constructor.
}
public static function handleAllEvents(event:Event):void {
Alert.show("Some event happened.");
}
}
}
Link (at the bottom):
http://livedocs.adobe.com/flex/3/html/help.html?content=events_05.html
If you use one handler for all events, you'll likely end up casting the generic incoming event to the more specific event inside each of the different if statements.
I would at the least have different handlers for different event types.
Ultimately it depends on what you need the event handler(s) to do.
Related
I am new to Flex (got assigned to maintain an old project at work) and am having some trouble getting data binding to work correctly. I have a popup form class, AddOffer.mxml which uses a model AddOfferModel.as. On my popup form, I have the following component:
<mx:FormItem label="{getResource('addOffer.form.OFFER_DATE')}:"
labelWidth="90">
<views:OfferWindowDatesFragment
id="offerWindowField"
start="{model.offerStartDate}"
stop="{model.offerStopDate}" />
</mx:FormItem>
My AddForm.mxml file also has some embedded actionscript where I define my 'model' variable:
[Bindable]
public var model:AddOfferModel;
The model variables I am trying to bind to are standard getters/setters and look like this inside AddOfferModel.as:
[Bindable]
public function set offerStartDate(val:EditableInstant):void
{
_offerStartDate = val;
}
public function get offerStartDate():EditableInstant
{
return _offerStartDate;
}
private var _offerStartDate:EditableInstant;
[Bindable]
public function set offerStopDate(val:EditableInstant):void
{
_offerStopDate = val;
}
public function get offerStopDate():EditableInstant
{
return _offerStopDate;
}
private var _offerStopDate:EditableInstant;
Inside the OfferWindowDatesFragment component class, the start and stop variables look like this:
[Bindable]
public function set start(val:EditableInstant):void
{
_start = val;
}
public function get start():EditableInstant
{
return _start;
}
private var _start:EditableInstant;
[Bindable]
public function set stop(val:EditableInstant):void
{
_stop = val;
}
public function get stop():EditableInstant
{
return _stop;
}
private var _stop:EditableInstant;
Basically, I just want to bind the start and stop variables in my OfferWindowDatesFragment class to the offerStartDate and offerStopDate variables in the AddOfferModel.as file. Whenever I access the start/stop variables in functions inside the OfferWindowDatesFragment class, they are null.
I have an event listener function that gets triggered in OfferWindowDatesFragment anytime a user selects a new date, it looks like this:
private function changeOfferDate():void
{
start.currentValue = offerDateEditor.start;
stop.currentValue = offerDateEditor.stop;
}
Every time I reach this function, it throws up an error because 'start' and 'stop' are both null ... but should have been initialized and bound already. If I look at the variables in the debugger, I can confirm that values on the right side of the assignment expression are valid, and not what is causing the error.
I am not real familiar with how initialization works in Flex, and I assumed as long as I instantiated the component as seen in the first code snippet at the top of my post, it would initialize all the class variables, and setup the bindings. Am I missing something? Perhaps I am not properly initializing the model or class data for AddForm.mxml or AddFormModel.as, thereby binding null references to the start/stop fields in my OfferWindowDatesFragment class?
Any help would be greatly appreciated. Thanks!
EDIT:
I looked into this further and tried using Mate to inject the 'model' variable inside AddOffer.mxml with a valid AddOfferModel object:
<Injectors target="{AddOffer}" debug="{debug}">
<ObjectBuilder generator="{AddOfferModel}" constructorArguments="{scope.dispatcher}" cache="local"/>
<PropertyInjector targetKey="model" source="{lastReturn}" />
</Injectors>
I load the AddOffer.mxml dialog as the result of a button click event on another form. The function that pops it up looks like this:
public function addOffer():void
{
var addOfferDialog:AddOffer = new AddOffer();
addOfferDialog.addEventListener("addOffer", addOfferFromDialog);
modalUtil.popup(addOfferDialog);
}
It doesn't seem to be assigning anything to the 'model' variable in AddOffer.mxml. Does loading a view/dialog this way not trigger an injection from Mate by chance? (I realize this last part might belong in the Mate forums, but I'm hoping somebody here might have some insight on all of this).
In AddOffer.mxml, you have this code:
[Bindable]
public var model:AddOfferModel;
Is there something outside AddOffer.mxml that is setting this to a valid AddOfferModel? There should be. The nature of how the Flex component life cycle means that you can expect that things may be null at times as a View builds. So you should build your components to be able to "right themselves" after receiving bad data, if the data eventually comes good.
Data binding is one way to do this, but it may not paper over everything depending on what else is going on.
Have you verified that the model value you're getting is not null at the point where the user selects the date and that its offerStartDate and offerEndDate properties have been populated with valid EditableInstants? If both of those are correct, I'd start looking for pieces of the Views that expect to have stuff at a given instant and then don't recover if it is provided later.
I am trying to dispatch a custom event from one flex module to another.
The code which dispatch the event is as below
Application.application.Destination.child.dispatchEvent(
new AlgoEvent(AlgoEvent.GETFROMPARENT_LOCAL_EVENT));
here AlgoEvent is a custom event
on the other side the module which catches and handles the event has this code:
public function sendParametersToChild(e:AlgoEvent):void
{
//some codes
}
but when the statement Application.application.Destination.child.dispatchEvent(new AlgoEvent(AlgoEvent.GETFROMPARENT_LOCAL_EVENT)); is executed the debugger give the following run time exception:
TypeError: Error #1034: Type Coercion failed: cannot convert resources.events::AlgoEvent#4182239 to resources.events.AlgoEvent.
at flash.events::EventDispatcher/dispatchEventFunction()
at flash.events::EventDispatcher/dispatchEvent()
at mx.core::UIComponent/dispatchEvent()[C:\autobuild\3.2.0\frameworks\projects\framework\src\mx\core\UIComponent.as:9298]
at components::Destination/sendTimeToChild()[E:\FlexProjects\MyApp\src\components\Destination.mxml:99]
at components::Destination/updateParameters()[E:\FlexProjects\MyApp\src\components\Destination.mxml:206]
at components::Destination/__CreateBasketButton_click()[E:\FlexProjects\MyApp\src\components\Destination.mxml:558]
I am not able to identify what is going wrong here.
Please help to solve this problem
This is my Event class
public class AlgoEvent extends Event
{
public static const GETFROMPARENT_LOCAL_EVENT:String = "getfromparent_local";
private var eventType:String;
public function AlgoEvent(eventType:String, bubbles:Boolean=false, cancelable:Boolean=false)
{
super(eventType,bubbles,cancelable);
this.eventType=eventType;
}
}
While debugging am getting error in this funcion of UIComponent class
override public function dispatchEvent(event:Event):Boolean
{
if (dispatchEventHook != null)
dispatchEventHook(event, this);
return super.dispatchEvent(event);
}
Excaxtly this line gives the error: dispatchEventHook(event, this);
Import the AlgoEvent class in the main application and create a reference to it.
import resources.events.AlgoEvent;
private var dummyEvent: AlgoEvent;
Some explanations for this could be found here: Module domains
If your custom event doesn't carry any special event properties you could workaround your problem by using the standard Event class.
dispatchEvent(new Event(AlgoEvent.GETFROMPARENT_LOCAL_EVENT));
I had the same problem when dispatching, solved overriding two functions:
override public function clone():Event
{
return new AlgoEvent(type, bubbles, cancelable);
}
override public function toString():String
{
return formatToString("AlgoEvent","type"","bubbles","cancelable","eventPhase");
}
hope it helps out :)
Mr. splash suggested a solution which worked fro me:
Try to make the Custum Event (Algo Event in my case) class known to the main application.
I.e import it in the main application and create a variable of it..
And it works for a main reason>>when we try to communicate betwwen the modules using event dispatching what happens is :the modules are loaded at the run time but the classes like event classes are linked to the modules at the run time..
But the Event class is compiled before the modules are loaded..
application defines a Custum Event Class at compile time, and the module defines its own Custum Event Class when it is published. Then when the application is run, the Custum Event Class dispatched in the application doesn't match the one in the module
swf.
For the problem which is causing this error one can check the link:
http://www.kirupa.com/forum/showthread.php?t=320390
and also
http://www.jeffdepascale.com/index.php/flash/custom-events-in-loaded-swf-files/
Mate framework takes care of all this.
It gives you a global event bus, for all modules in your app.
http://mate.asfusion.com/
Try to override the clone() method in your customized Event,AlgoEvent.
Add the following code to your AlgoEvent.as class and try:
override public function clone():Event{
return new AlgoEvent(eventType,bubbles,cancelable);
}
HTH.
Your custom Event class should look like this:
public class AlgoEvent extends Event
{
public static const GETFROMPARENT_LOCAL_EVENT:String = "getfromparent_local";
public function AlgoEvent(type:String, bubbles:Boolean=false, cancelable:Boolean=false)
{
super(type, bubbles, cancelable);
};
override public function clone():AlgoEvent
{
return new AlgoEvent(type, bubbles, cancelable);
};
};
You should use the Event's inherited type property instead of creating a new one.
Also, the UIComponent has it's own dispatchEvent method, so you don't have to create your own - only if it works differently to the inherited one.
Regards,
Rob
Okay, it must be said that what you're doing, from an architectural standpoint, is wrong. Calling Application.application is bad for so many reason, especially if you're then starting to go down the display tree. The second any of the children changes, your build is now broke, and you won't know that until runtime because it's a module.
What you need is an application framework. A way to increase complexity without decreasing maintainability. There are many out there, but my personal favorite is Parsley. I've used it on many very large projects with much success. The problem you're trying to solve right now, dispatching one event where the other module listens for it, is extremely trivial (can be done in about 3 lines of code).
I recommend you look it over as well as my presentation on an introduction to parsley.
I am loading an swf created in flash professional cs5 via the loader class into a flex 4.1 application. The flash file contains multiple movieclips that are exported for actionscript and those movieclips exist in many instances throughout the movie.
Iterating through everything, comparing class types seems to be the most easy but also the most redundant way to solve this. Is there any way of using the class name as a kind of global selector to access the clips?
I could also make the sub-clips in the flash listen for an event on which they perform an action, but I am not really sure what might be best.
In cases like these, I find that a good way to solve the problem is to create a statically accessable class that manages instances of other classes that are registered with it on instantiation. As an example...
public class GlobalStopper{
private static var clips:Array = [];
public static function add(mc:MovieClip):void{
clips.push(mc);
}
public static function stop():void{
var mc:MovieClip;
for(var i:int = 0, ilen:int = clips.length ; i < ilen ; i++){
mc = clips[i] as MovieClip;
if (mc) mc.stop();
}
}
}
and...
public class GloballyStoppableMovieClip extends MovieClip{
public function GloballyStoppableMovieClip(){
GlobalStopper.add(this);
}
}
Any and all instances of GloballyStoppableMovieClip are instantly registered with the GlobalStopper, so calling
GlobalStopper.stop();
...will stop all registered movieclips.
You can add in any other functions you want. Furthermore, instead of having add accept MovieClip instances, you could have it accept IStoppable or IPlayable objects that implement public functions stop() and play() that your movieclip subclass (or non-movieclip object that also might need to stop and play!) then implements.
But as for jQuery-like selectors? Not really the way I'd handle this particular issue.
i guess typing it out did the trick. i used the event solution:
in the root timeline i placed a function like this:
function cause():void {
dispatchEvent(new Event("do stuff",true));
}
and in the library clip's main timeline goes:
DisplayObject(root).addEventListener("do stuff", function (e:Event=null) {
... whatever ...
});
this is dirty but you get the idea.
I need to pass along a string with my FileReference, or provide that string as an argument when an event fires. To be clear, it really annoys me that AS3 doesn't allow you to pass parameters on events.
Right now, I've extended the FileReference class to include an additional variable. I'm trying to get this to compile, but it won't compile; I think I don't know how to import this class correctly. If you can tell me how to import this class correctly so that I no longer get Error: Type was not found or was not a compile-time constant at compile time that would be great.
This is the extended FileReference class:
import flash.net.FileReference;
public class SxmFR extends FileReference {
public var housenum:String = "";
public function SxmFR(str:String) {
housenum = str;
super();
}
}
I've tried that in a .mxml and a .as in the same folder. Neither is automatically imported.
I've also tried to extend the Event class, but I couldn't figure out how to make the event dispatch, since I need to respond to the Event.COMPLETE event. If you can tell me how to make it dispatch on this, it also might work.
Please help me get this figured out, and much love and thanks to all involved. : )
If you add your event listener as a closure you have access to the variables in the current function:
function myFunction(): void {
var aParam: String = "This is a parameter";
dispatcher.addEventListener("eventName", function (e: Event): void {
// you can access aParam here
trace(aParam);
});
}
The aParam inside the function will have the same value as it had when addEventListener was called.
I'm trying to create a collection class in Flex that is limited to housing a specific type of data that i am using (an interface). I have chosen not to extend the ArrayCollection class as it's too generic and doesn't really give me the compile time safety that i'm after. In it's simplistic form my collection contains an array and i manage how objects are added and removed, etc.
What i really want to be able to do is use these collections in for each loops. It definitely doesn't seem as straight forward as say c# where you just implement IEnumerable and IEnumerator (or just using the generic Collection). Is there a way to do this in action script and if so any info on how it is achieved?
Cheers
You need to extend the Flash Proxy class. Extending Proxy allows you to alter how 'get' and 'set' work, as well as 'for..in' and 'for..each' loops. You can find more details on the Livedocs.
Here's an example for your issue:
package
{
import flash.utils.Proxy;
import flash.utils.flash_proxy;
public class EnumerableColl extends Proxy
{
private var _coll:Array;
public function EnumerableColl()
{
super();
_coll = [ 'test1', 'test2', 'test3' ];
}
override flash_proxy function nextNameIndex( index:int ):int
{
if ( index >= _coll.length ) return 0;
return index + 1;
}
override flash_proxy function nextValue( index:int ):*
{
return _coll[ index - 1];
}
}
}
Take a look at Vector<>. That is about as best as you can go for a typed collection in Flex (4 onwards). However, you will need to implement your own class otherwise. One way, it seems, is to use the Iterator Pattern.
Also, take a look at this SO post.