Flexache

Do you want more about Flex, Flash and Actionscript?

IT Failed is no longer updated with this kind of info.

For better convenience I created a new blog with only Flex issues...

the flexache

get now to get your fresh medicines

 http://flexache.blogspot.com/

Flex4, how to wait object to be completely initialized; how to give time to objects to be completely initialized

Suppose that you have an Object called Circus. This object is too complex (like a real circus). The follow init() function creates the circus it but in real programming world the Circus object is not prepared because the Circus must be render its components, update several graphics objects .

internal function init():void{

       //create my.. circus…

       myCircus=new Circus(“My X-circus");

       //initialize

       myCircus.x=10; myCircus.y=40;

       //play

       myCircus.play();

       myCircus.cashier.addMoney(100.50); //this might be wrong, as the circus in not ready yet!

}

This problem occurred on simpler objects also… like the Flex’s Label. If on “applicationComplete” you apply a value to “text” property of a Label a text (i.e. “hellow world”) and right after you try to get the “width” of the Label object, you might be get WRONG value, a not real width; this because the Label object is not yet prepared.

Well, how to get that an object is completed? With Flex’s Label, the event you must Listen is the “FlexEvent.UPDATE_COMPLETE” and not other “UPDATE_COMPLETE” because Flex offers and other from other Eventxxx classes. Note that this is working in Flex 4.0.

So… the Circus object must supports and dispatch once upon a time the “FlexEvent.UPDATE_COMPLETE” to continue in safe way the calculations with its properties.

But, what happen if the Circus doesn’t supports this event? Unfortunately this is happening in real world with several 3^rd party components / object.

Bellow there is a solution that is not so professional but it is the only chance to make it work! ;) What I do here is that I am working for a while with Event.ENTER_FRAME, with this way I give some time to then whole application and its running objects to complete uncompleted calculations.

//this is my own counter to count the passed time.

internal var myWaitCounter:int;

internal function init():void{

       //create my.. circus…

       myCircus=new Circus(“My X-circus");

       //initialize

       myCircus.x=10; myCircus.y=40;

       //prepare and activate my listener pf ENTER_FRAME event

       myWaitCounter=0;

       addEventListener(Event.ENTER_FRAME,Handler_WaitForCompletion);

}

internal function Handler_WaitForCompletion (e:Event):void{

       //add to my counter the time

       myWaitCounter+=1000/ Object(FlexGlobals.topLevelApplication).stage.frameRate;

       //if, 500ms (0,5sec) passed, then call the start() after remove then listener

       //in general it is very important to remove the listeners where you don’t need any more

       if (myWaitCounter >=500) {

              removeEventListener(Event.ENTER_FRAME,Handler_WaitForCompletion);

              start();

       }

}

protected function start():void{

       //now you are ready to play with you circus safely!

       myCircus.play();

}

Flex, Determining which server/domain a SWF is hosted on

situation
	Here’s a handy tip which can help you when deploying Flex applications on mulitple servers (such as a staging/production server). Basically you can listen for the Application tag to dispatch the applicationComplete event, grab the URL of the SWF using the loaderInfo.url property, and then use the URLUtil.getServerName() method to parse out the server name.
problem
	adobe flex4 flex 4.0 AS3.0 Determining which server/domain a SWF is hosted on | How to get the domain where the swf is hosted ---- > page: dn
difficulty level
	0/10 :)))
compatibility
	flex4, as3
solution
	In prior version of Flex 4.0 use this: URLUtil.getServerName(Application.application.loaderInfo.url); In 4.0 use this: because Application is no longer available in 4.0 URLUtil.getServerName(FlexGlobals.topLevelApplication.url)

Flex4, trace function is not working anymore!

situation
	This is known bug! This problem occurred when you exported a “release” previously; thenceforth the trace() messages are not appeared in the console window. !!! If you are beginner on Flex, read the "attention" at the bottom of this post! !!!
problem
	adobe flex4 AS3.0 Flex4, trace function is not working anymore! ---- > page: dn
difficulty level
	3/10 :))
compatibility
	flex4, as3
solution
	Try 1 1. Clean the build: Project -> Clean -> Clean project (select this one specific from the list) -> ok 2. “Debug” the application (pressing the “bug” button); rebuild will be done 3. The problem should be solved! Otherwise try try2. Try 2 1. Restart the Flex / Flash builder IDE 2. Restart the browser with Adobe Flash Debugger Player 3. Clean the build: Project -> Clean -> Clean project (select this one specific from the list) -> ok 4. “Debug” the application (pressing the “bug” button); rebuild will be done 3. The problem should be solved!
attention
	Important note for beginners: You should “debug” the application (pressing the “bug” button) and not “run” the application (pressing the “play” button) to see the trace() messages at the console window. In “run” mode the trace() message are omitted.

flex4, how to make an image brighter, i.e. for focus purposes, without modify it

situation
	how to make easy(!) modifications in Image components with out modifying their data. The data modification (image modification) requires a lot cpu resources as result low performance.
problem
	adobe flex4 AS3.0 how to make an image brighter, i.e. for focus purposes, without modify it > page: dn
difficulty level
	2/10 :)
compatibility
	flex4, as3
solution
	- drop a Label on the Image component to cover it, clear text property - on this Label... set as background color the white color - also set as blendmode the "overlay" value - also set as backgroundAlpha the value 0.5 - now... on runtime play with "alpha" property of the Label with values 0..400

Flex: how to make a image cache? (easier way) - REFdn4007673813

situation
	how to make a image cache?
problem
	adobe flex4 AS3.0 the image component how to load images save them to cache… and how apply them to Image components --- > page by dn
difficulty level
	9/10 :(
solution
	In order to make a cashe of the photos/images, I do the follow simple way: - With URLLoader I download the data… the "Complete" event gives me the "data" property… in this property the data of the image is in binary format (don't be afraid). I save this "data" to another variable (or array) of Object type. For this example, I named this variable "downloadData" you will see bellow. - In order to load the data on a visual component Image, I do the follow code: myImage.data=downloadData;
attention
	no attentions!

How to Cache Images in Your Flex Application - REFdn5077575832

Caching images in your Flex application can greatly improve performance and reduce the overhead of loading external resources.
And I’m not simply talking about using the cacheAsBitmap property to improve rendering performance or the cachePolicy property to speed up animations. I’m talking about caching the actual bitmap data of an image.
To get started, you’ll need a hash map to store the image data. A Dictionary or an associative array will also work just fine.
Loading an image for the first time is the same as usual. You create a new Image object and add a listener for the COMPLETE event:

var image : Image = new Image (); image.addEventListener (Event.COMPLETE, onImageComplete);

Once the image has finished loading, you add a copy of the bitmap data to the hash map using the image URL as the hash key:

private function onImageComplete (event : Event) : void {     var image : Image = event.target as Image;     if (! imageCache.containsKey (image.source))     {         var bitmapData : BitmapData = new BitmapData             (image.content.width, image.content.height, true);         bitmapData.draw (image.content);         imageCache.put (image.source, bitmapData);     } }

Now we can use the image as many times as we want without ever having to load it again!
To take advantage of this, you’ll need to check the hash map every time you create a new image (or change the source property) to see if you’ve already cached it:

var image : Image = new Image (); image.addEventListener (Event.COMPLETE, onImageComplete); if (imageCache.containsKey (imageURL)) {     image.source = new Bitmap (imageCache.getValue (imageURL)); } else {     image.source = imageURL; }

And that’s it!
If you have an application that loads a large number of images you may want to limit the number of cached images to prevent the Flash player memory usage from getting out of hand, but in general caching even several dozen large images only results in a slightly increased footprint.

flex, air, How to write a file where the application is located

problem
	adobe flex4 AS3.0, filestraem (air) How to write a file where the application is located | the mystery "fileWriteResource" hidden error | how to write files in applicationDirectory (where is not allowed) [tested in windows only] --- > page by dennis
solution
	How to write a file where the application is located in the follow example, the variable "filename" is String and has as value the the file name without path, i.e.: "sample.txt" the follow code doesn't work, produces an error "fileWriteResource" that is not even thrown!     var newFile:File=File.applicationDirectory.resolvePath(filename); use the follow code:     var newFile:File=File(File.getRootDirectories()[0]).resolvePath(File.applicationDirectory.nativePath+File.separator+filename);  //I am not kidding... it is working