[Flex 4] Module doesn't unload due to mx.styles.StyleManagerImpl - moduleFactroy?

Question

I have a custom component extending skinnableContainer and has a ButtonBar and Groups in it, which I use in my module.
If I do not: import CustomClass; CustomClass; in my main application, then the module is stuck with mx.styles.StyleManagerImpl - moduleFactroy in the profiler.
Why is that? I though that modules in Flex 4 have their own style manager and I should not have this problem? What I am missing?
And also since I'm building a modular system and someone builds a module swf for it, he will have to include his components along with it, so then I can reference them in my mainApp, so his module doesn't get stuck in memory. Is that the way it's supposed to work or I am doing something work ?

Answer 1

Thanks for the reply Darrell, as you can see I've started looking into the unloading modules and profiling topic, as I progress with my modular application.
So I am kinda new in both, although I've read all articles I could find I have some problems so I've created a very simple application example again, so you could easily look into it and hopefully spread some light in my confusion.
http://filip.nedyalkov.net/moduleImageStuck/ view source is enabled so you can confirm test what I will describe here, use it to view the source, or download to profile the results I post here.
The scenario of the example is: On app creation 2 modules are loaded and created via moduleInfo:
MyModule.mxml
<s:Group><mx:Image id="imageLoader" /></s:Group>
MyModule2.mxml
<s:Group> 
<local:HNav /></s:Group>
HNav.mxml - SkinnableContainer
<s:ButtonBar><s:dataProvider><s:ArrayCollection><fx:String>B1</fx:String><fx:String>B2</fx:String></s:ArrayCollection></s:dataProvider></s:ButtonBar>
So with the example provided I've made 3 test cases, where I get different results.
1) The first one is as the example is currently setup to run, which means:
- these 2 imports are NOT included in the main app
//import mx.controls.Image; Image;
//import HNav; HNav;
- both modules are loaded via moduleInfo "load()" only method (moduleFactory is not passed).
Darrell, here what I wonder is: "In Flex 4 a module will not be pinned in memory by StyleManager unless you explicitly set styles from the module into the top-level StyleManager". With this said I should be not having my modules pinned into memory with this setup, right? Or I am missing something? Here is the profiler result for both modules - both FlexModuleFactories remain:
2) In the second test case I included the imports along with the current setup:
import mx.controls.Image; Image;
import HNav; HNav;
The result here was nice, both FlexModuleFactories were gone in the profiler. But the question remains - why do I have to declare in my main app these classes when in Flex 4 the StyleManager shouldn't pin them like in case 1) in memory.
3) I also post here this test case 3 because I find it as an unexpected behavior or bug maybe with the mx:Image class.
Here we still have the imports but instead of "load()" we pass in the moduleFactory: load(null,null,null,moduleFactory);
The result of this is having MyModule's FlexModuleFactory stuck in memory with reference with the StyleManager and MyModule2 is completely gone, so it's ok.
Here is the profiler result:
So the question here along with the idea it could be a bug, is: Should I pass moduleFactory to modules I plan to unload? I wanted to pass moduleFactory instead of declaring same styles for each module.
Darrell I'm kinda stuck on these questions, cause I've found nothing on this in articles, and I tried really hard to put my very complexed project into this simple examples, so I get the methodology and logic of how a dynamic system which constantly loads and unloads modules should be structured.
I really hope you find the time to answer me here till I get this running. I'm sure others will find it useful too. Thanks in advance.