The thing is - there's nothing wrong with the Singleton implementation, it
works just fine in my app (and inside modules). But when a module loads
another module, it stops behaving as a Singleton.
So it seems like a Flex bug ....?
On 06/12/2007, bjorn - <[EMAIL PROTECTED]> wrote:
>
> Thanks for the link, I'll check it out (but I'm from a Java world so I
> like my .getInstance() ;-) )
>
> Here's my singleton test implementation:
>
>
>
> package com.juicability.moduletesting
> {
> public class TestSingleton
> {
> private static var instance:TestSingleton; // the only instance of this
> singleton
>
> /**
> * Singleton - use getInstance() instead!
> **/
> public function TestSingleton()
> {
> if (TestSingleton.instance != null)
> {
> throw new Error("TestSingleton is a singleton class, getInstance()
> should be used.");
> }
> }
>
> /**
> * Get the only instance of the TestSingleton
> * @return TestSingleton instance
> **/
> public static function getInstance():TestSingleton
> {
> if (instance == null)
> {
> instance = new TestSingleton();
> trace("TestSingleton - instance was null, so created new
> instance");
> } else {
> trace("TestSingleton already instanciated, so returning instance..");
> }
> return instance;
> }
> }
> }
>
>
>
>
> On 05/12/2007, riaengineer <[EMAIL PROTECTED]> wrote:
> >
> > I've found using Darron Schall's singleton implementation seems to
> > work great for my projects.
> >
> > http://www.darronschall.com/weblog/archives/000274.cfm
> >
> > Short of that can you post your singleton implementation code (or at
> > least the constructor) ?
> >
> > --- In [email protected] <flexcoders%40yahoogroups.com>, "bjorn
> > -" <[EMAIL PROTECTED]> wrote:
> > >
> > > I've made a simple testcase with a singleton and three Flex projects:
> > >
> > > 1. MainApp
> > > 2. ModuleOne
> > > 3. ModuleTwo
> > >
> > > MainApp loads ModuleOne which loads ModuleTwo (it could also load both
> >
> > > modules, the behaviour I describe below seems to be the same in both
> > cases).
> > >
> > > I have created a TestSingleton.as which implements the Singleton
> > pattern (as
> > > far as it can be tanken in AS anyway ..)
> > >
> > > Here's TestSingleton.as's getInstance() method:
> > >
> > > /**
> > > * Get the only instance of the TestSingleton
> > > * @return TestSingleton instance
> > > **/
> > > public static function getInstance():TestSingleton
> > > {
> > > if (instance == null)
> > > {
> > > instance = new TestSingleton();
> > > trace("TestSingleton - instance was null, so created new instance");
> > > } else {
> > > trace("TestSingleton already instanciated, so returning
> > instance..");
> > > }
> > > return instance;
> > > }
> > >
> > >
> > > If I put the singleton in MainApp, and then getInstance() it from
> > ModuleOne
> > > and ModuleTwo I'll get this in my trace:
> > >
> > >
> > > [SWF] C:\dev\FlexWorkspace\ModuleTestMainApp\bin\ModuleTestModuleOne-
> > > debug.swf - 450,372 bytes after decompression
> > > TestSingleton - instance was null, so created new instance
> > > [SWF] C:\dev\FlexWorkspace\ModuleTestMainApp\bin\ModuleTestModuleTwo-
> > > debug.swf - 446,193 bytes after decompression
> > > TestSingleton already instanciated, so returning instance..
> > >
> > > .. which is the expected behaviour.
> > >
> > > However, if I put TestSingleton.as in ModuleTwo, I get this:
> > >
> > > [SWF] C:\dev\FlexWorkspace\ModuleTestMainApp\bin\ModuleTestModuleOne-
> > > debug.swf - 450,372 bytes after decompression
> > > TestSingleton - instance was null, so created new instance
> > > [SWF] C:\dev\FlexWorkspace\ModuleTestMainApp\bin\ModuleTestModuleTwo-
> > > debug.swf - 446,193 bytes after decompression
> > > TestSingleton - instance was null, so created new instance
> > >
> > > .. it doesn't behave as a singleton anymore ..
> > >
> > > Can anyone explain why? :-)
> > >
> > > --
> > >
> > > ========================
> > > http://www.juicability.com - flex blog
> > > http://www.43min.com - funny movies
> > >
> >
> >
> >
>
>
>
> --
>
> ========================
> http://www.juicability.com - flex blog
> http://www.43min.com - funny movies
>
--
========================
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