[flexcoders] Re: Inline EventListener in MXML tags - confusing description in Developers guid
Instead of waiting for an answer i just ran a lil' test:
?xml version=1.0 encoding=utf-8?
mx:Application creationComplete=eventListener(event)
xmlns:mx=http://www.adobe.com/2006/mxml;
mx:Script
![CDATA[
import flash.utils.getQualifiedClassName;
import mx.events.FlexEvent;
private function eventListener(event:Event):void {
trace(getQualifiedClassName(event)+#+event.type);
switch(event.type) {
case FlexEvent.APPLICATION_COMPLETE:
this.registeredEventListenerTrace(FlexEvent.CREATION_COMPLETE);
this.registeredEventListenerTrace(FlexEvent.APPLICATION_COMPLETE);
this.removeEventListener(FlexEvent.CREATION_COMPLETE,
eventListener, false);
this.removeEventListener(FlexEvent.APPLICATION_COMPLETE,
eventListener, false);
this.registeredEventListenerTrace(FlexEvent.CREATION_COMPLETE);
this.registeredEventListenerTrace(FlexEvent.APPLICATION_COMPLETE);
break;
case FlexEvent.CREATION_COMPLETE:
this.removeEventListener(FlexEvent.CREATION_COMPLETE,
eventListener, false);
this.registeredEventListenerTrace(FlexEvent.CREATION_COMPLETE);
this.registeredEventListenerTrace(FlexEvent.APPLICATION_COMPLETE);
this.addEventListener(FlexEvent.APPLICATION_COMPLETE, eventListener,
false, 0, true);
this.registeredEventListenerTrace(FlexEvent.CREATION_COMPLETE);
this.registeredEventListenerTrace(FlexEvent.APPLICATION_COMPLETE);
break;
}
}
private function registeredEventListenerTrace(type:String):void {
trace(\t + type + is registered: +
this.hasEventListener(type));
}
]]
/mx:Script
/mx:Application
I was surprised that the FlexEvent.CREATION_COMPLETE can't be removed. This is
quite
shocking...
Best regards.
--- In flexcoders@yahoogroups.com, florian.salihovic [EMAIL PROTECTED]
wrote:
Quoted from Adobe Flex Developers Guide, page 78
However, it is best practice to use the addEventListener() method.
This method gives you greater control over the event by letting
you configure the priority and capturing settings, and use event constants.
In addition, if you use addEventListener() to add an event handler, you can
use removeEventListener() to remove the handler when you no longer need
it. If you add an event handler inline, you cannot call removeEventListener()
on that handler.
- End of Quote -
What i think is a little bit confusing is, that it's said that inline
EventListener can't be
removed? Or is it just a little bit unluckily expressed? Why can't i just
call
removeEventListener in ActionScript on the type of event declared in MXML?
Best regards from Germany
Re: [flexcoders] Re: Inline EventListener in MXML tags - confusing description in Developers guid
you could compile with the -keep option to see what is output underneath the
covers.
and then what i think might be the case
pure speculation follows
consider that the mxml gets converted to as. now in mxml you could have
something event={a=1}
or
something event=function(event,'sdfdsf')
or...
now if i was to write a converter for something like this i would wrap the
function which invokes whatever the user specified (i am not certain if this
is the case) in order to make my approach as flexible as possible
jpn
On Mon, Jul 21, 2008 at 12:18 PM, florian.salihovic
[EMAIL PROTECTED] wrote:
Instead of waiting for an answer i just ran a lil' test:
?xml version=1.0 encoding=utf-8?
mx:Application creationComplete=eventListener(event)
xmlns:mx=http://www.adobe.com/2006/mxml;
mx:Script
![CDATA[
import flash.utils.getQualifiedClassName;
import mx.events.FlexEvent;
private function eventListener(event:Event):void {
trace(getQualifiedClassName(event)+#+event.type);
switch(event.type) {
case FlexEvent.APPLICATION_COMPLETE:
this.registeredEventListenerTrace(FlexEvent.CREATION_COMPLETE);
this.registeredEventListenerTrace(FlexEvent.APPLICATION_COMPLETE);
this.removeEventListener(FlexEvent.CREATION_COMPLETE,
eventListener, false);
this.removeEventListener(FlexEvent.APPLICATION_COMPLETE,
eventListener, false);
this.registeredEventListenerTrace(FlexEvent.CREATION_COMPLETE);
this.registeredEventListenerTrace(FlexEvent.APPLICATION_COMPLETE);
break;
case FlexEvent.CREATION_COMPLETE:
this.removeEventListener(FlexEvent.CREATION_COMPLETE,
eventListener, false);
this.registeredEventListenerTrace(FlexEvent.CREATION_COMPLETE);
this.registeredEventListenerTrace(FlexEvent.APPLICATION_COMPLETE);
this.addEventListener(FlexEvent.APPLICATION_COMPLETE, eventListener,
false, 0, true);
this.registeredEventListenerTrace(FlexEvent.CREATION_COMPLETE);
this.registeredEventListenerTrace(FlexEvent.APPLICATION_COMPLETE);
break;
}
}
private function registeredEventListenerTrace(type:String):void {
trace(\t + type + is registered: +
this.hasEventListener(type));
}
]]
/mx:Script
/mx:Application
I was surprised that the FlexEvent.CREATION_COMPLETE can't be removed. This
is quite
shocking...
Best regards.
--- In flexcoders@yahoogroups.com flexcoders%40yahoogroups.com,
florian.salihovic [EMAIL PROTECTED] wrote:
Quoted from Adobe Flex Developers Guide, page 78
However, it is best practice to use the addEventListener() method.
This method gives you greater control over the event by letting
you configure the priority and capturing settings, and use event
constants.
In addition, if you use addEventListener() to add an event handler, you
can
use removeEventListener() to remove the handler when you no longer need
it. If you add an event handler inline, you cannot call
removeEventListener()
on that handler.
- End of Quote -
What i think is a little bit confusing is, that it's said that inline
EventListener can't be
removed? Or is it just a little bit unluckily expressed? Why can't i just
call
removeEventListener in ActionScript on the type of event declared in
MXML?
Best regards from Germany
--
j:pn
\\no comment
[flexcoders] Re: Inline EventListener in MXML tags - confusing description in Developers guid
--- In flexcoders@yahoogroups.com, Johannes Nel [EMAIL PROTECTED]
wrote:
you could compile with the -keep option to see what is output
underneath the
covers.
and then what i think might be the case
pure speculation follows
consider that the mxml gets converted to as. now in mxml you could
have
something event={a=1}
or
something event=function(event,'sdfdsf')
or...
now if i was to write a converter for something like this i would
wrap the
function which invokes whatever the user specified (i am not
certain if this
is the case) in order to make my approach as flexible as possible
One difference between adding a listener inline and adding a listener
in AS3 is that inline you have a choice of arguments...you can have
no argument, an arbitrary argument, or send the event. In AS3, the
event is always passed. If your function doesn't expect to get the
event as its one and only argument, you will get a runtime error.
This does imply that whatever goes on in addEventListener, it is way
stricter than what happens when you add the listener inline. It
would be nice if the finer points were documented.
HTH;
Amy
