who the heck is worrying about using or not global variables??? it all depends on the architecture and mind state of the programmer.
I hate flex, but I cant say no to a client…. finding this post was really useful :)

namaste
Pippo

It worked for me.

I was trying to get the values of 2 variables created for use in one mxml state file to be available in another one so that I could post them to a server. The two files are in the same package. The main application mxml imports the package they are in.

I would like to know a better way than what I have done. If there is one.

George

It is always best practice to contain the data in the class designed specifically for that class.

With that said, there are always reasons to do global variables…

For instance, I have my components set up to display different tools depending on the access of the user (Set through a remote object component). There may be an edit button if the person has edit rights for instance.

I have a global user object that each of the components can easily refer to. I also have a bind set so that the components can react if a variable changes (like if the user logs out).

I could be wrong on this… But I don’t see another way to easily get around that by keeping the information in the login component.

This is only one example, I can think of numerous ones that I’ve encountered over the past 30 years of coding.

However with that said you should ALWAYS ask yourself, is this the best place to store the variables? What and how do other pieces of code have to do to access them? It’s never best practice to store 95% of data in public variables (unless you’re doing BASIC code that is… ;)

several ways:

.outerDocument

.parentDocument

if you have an id of the element just use the element.id.

Sorry, but on this one you’re quite wrong. There is a very common Flex scenario where using Singleton’s just doesn’t work, but Application.application does. Singleton’s don’t work when you build a modular system, where each module is its own swf, and loaded using SWFLoader or ModuleLoader. However, with such a modular system works great with globals loaded from Application.application. I use Application.application frequently, and have never encountered mem leaks like you describe.

The use of Singletons is the primary reason that Cairngorm doesn’t work with modular Flex apps. That and the problem of multiple instance of commands loaded into controllers causing things to double/triple/etc load.

NEVER bind to variables using Application.application

In my experience, it will create a memory leak in nearly all cases. If you must bind, use a singleton. I believe the best way to implement a singleton is the way it’s done in Cairngorm (I hate Cairngorm, but at least they do this one thing well).

I respect Mike, and I will grant that in some cases creating global variables using “Application.application” is acceptable (although I personally try to avoid it), but I think Mike probably should have given a little more caution in his blog post so as not to mislead developers who are new to Flex.

warning: unable to bind to property ‘application’ on class ‘mx.core::Application’ (class is not an IEventDispatcher)

But I can reference these in components and elsewhere and get the values of them. Can you not bind to the Application class?