I was getting this weird error whenever switching from a given state to it's parent state in a Flex 3.5 based project.

RangeError: Error #2006: The supplied index is out of bounds.
	at flash.display::DisplayObjectContainer/addChildAt()
	at mx.core::Container/addChildAt()
	at mx.effects::EffectManager$/removedEffectHandler()
	at Function/http://adobe.com/AS3/2006/builtin::apply()
	at mx.core::UIComponent/callLaterDispatcher2()
	at mx.core::UIComponent/callLaterDispatcher()

It threw me for a minute because I hadn't made any changes to effects since I last tested the application and I couldn't see any connection between the code I had just written and any effects in the app. But after hunting around I found the culprit. There's a set of components in a Canvas that gets removed when moving to the parent state. What I had done was separate those components into two Canvases(Canvi?). For whatever crazy reason the new second Canvas can't have a RemoveEffect. The code works fine if just the first Canvas has it, but if both or just the second Canvas has it then it throws that error.

side note: the reason it took me a while to find the source of the error was because I copy/pasted the canvas declaration only changing the id, and I forgot that there was a removedEffect associated with it.

But wait there's more. The reason I split the components into two distinct Canvases was so I could position one below and the other on top of a third major component in z-space. The solution was to add the first Canvas as a "firstChild" and the second Canvas as a "lastChild". That it seems was the problem. In mxml when changing states you apparently can't add a firstChild before adding a lastChild. so I copy and pasted the first Canvas below the second one, so that all the lastChild additions occurred before all the firstChild additions and voila, presto, it works.

The reason is that when you move from a state back to its parent state it follows the order in which you add components in the state declaration to remove them. If the first component you add is added as a firstChild then that get's removed first changing the indexes and number of children of the parent container. I guess the underlying state changing function already calculated what the lastChild index was, so when trying to remove a Child with the pre-calculated index of lastChild it triggered an index out of bounds error.

I'm getting used to Flash Builder 4, man is it fast. I came across this plugin by Lee Brimlow, it's SnipTreeView adapted to work with .mxml files and in FB4. Just download it from his blog and add it to the plugins folder, then restart. There's a quick video how to, highly recommended.

Flash Snippets [http://theflashblog.com/?p=1494]

Easily update any element's inner html with an ajax get request.

Simple get request

$('div_files').load('getfiles.php');

What it does is get the content of getfiles.php and uses it as the innerHtml for the div with id

'div_files'

Slightly more complex get request

var myHTMLRequest = new Request.HTML({url:'getfiles.php', update:'div_files'}).get({'user_id': 25});

In this get request, like the simple one you specify the location of the server side script, which happens to be in the same directory, and you specify the element who's innerHtml you want to update. After the

.get

you send a variable to the server, in this case

user_id

with the value 25.

Note: In the php file you'll need to use a

$_GET['user_id']

instead of

$_POST

I stumbled over this when I was building the CCMCP Library app but I suppose history's due to repeat itself. The problem is this: downloading a file from flex just doesn't work; A dialogue pops up, you choose a place to save the file, but when you hit save no file gets downloaded.

If you're sure the url is correct and you haven't made any syntax errors, then the most likely cause is that you've declared the

'fileRef'

variable within the

'download();'

function. The following code will work.

private var fileRef:FileReference = new FileReference();
 
public function download():void
{
fileRef.download(new URLRequest('http://web-site/file-name'), 'simple filename');
}

The problem's also documented at Adobe and Lynch Consulting