Resumable Downloads with AIR

Here is how a sample Request looks like:

GET /files/richflv/help/ExportOptions.flv HTTP/1.1
Referer: app-resource:/LoadingTest.swf
x-flash-version: 9,0,60,153
Range: bytes=1200000-1300000
User-Agent: Mozilla/5.0 (Windows; U; en) AppleWebKit/420+ (KHTML, like Gecko) AdobeAIR/1.0
Host: www.richapps.de

In Actionscript we can write a custom header like this:

var header1:URLRequestHeader = new URLRequestHeader("range","bytes="+currentBytesPosition+"-"+toRange);
var re:URLRequest = new URLRequest(downLoadURL);
re.requestHeaders.push(header1);
currentBytesPosition = toRange;
urlStream.load(re);

http://www.richapps.de/?p=113

Async APIs and Callback Functions

"Making the FileStream a member variable is also essential. If the FileStream were instead declared inside someFunction(), it would go out of scope when someFunction() returned and could be garbage collected before the file is read or events are delivered. Many people are surprised by this, but note that the only reference to the FileStream object is the member variable. The FileStream object has references on event listeners, etc. but only references to an object will protect it from collection."

Now, this will almost never happen to you because (a) the garbage collector runs incrementally and it'll take it a while to collect the FileStream object and (b) most file reads will finish and dispatch a complete event long before then. But it can happen, which of course means it'll probably only show up when doing big important demos.

http://blogs.adobe.com/simplicity

"It turns out I was incorrect about this and that some related objects, such as URLStream, are guaranteed to remain live until after they have dispatched a completion event. This behavior is both more useful and more intuitive; after all, it only makes sense that there would be a reference to the URLStream somewhere in the system while it's hanging around receiving data."

http://blogs.adobe.com/simplicity

adobe flex Job Trends @ indeed.com

Using Local Shared Object to store a serialized class instance

Using RemoteClass metadata triggers code gen in in the compilter to ensure that the class is registered with the VM before the application can use it, this includes receiving it from a network request.

private function getLSO() :void {
    so = SharedObject.getLocal("testData", "/");
    var b:ByteArray = (so.data.test as ByteArray)
    if(b){
        b.position=0;
        var o:Object = b.readObject();
        test = MyClass(o);
        n.text=test.name;
        p.text=test.price.toString();
        ta.text=test.toString();
    }   
    else{
        Alert.show("LSO testData does ot exist!");
    }      
}

private function setLSO():void {
    so = SharedObject.getLocal("testData", "/");
    var b:ByteArray = new ByteArray();
    b.writeObject(test);
    so.data.test=b;
    so.flush();
}

http://blog.739saintlouis.com

Flex Tip - Trigger validation when submitting form

<mx:Array id="validators">
   <mx:StringValidator source="{abbreviations}" property="text" required="true"/>
   <mx:StringValidator source="{subcode}" property="text" required="true"/>
   <mx:StringValidator source="{name}" property="text" required="true"/>
   <mx:StringValidator source="{letterType}" property="text" required="true"/>
   <mx:StringValidator   source="{scheduleType}" property="text" required="true"/>
</mx:Array>

<mx:Button
   label="Save"
   click="if( Validator.validateAll(validators).length==0 ){ doSave() }"/>

http://www.mikenimer.com

Using the flash.* classes in MXML

<?xml version="1.0" encoding="utf-8"?>
<!-- http://blog.flexexamples.com/2007/09/26/using-the-flash-classes-in-mxml/ -->
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml"
        xmlns:flash.filters="flash.filters.*"
        layout="vertical"
        verticalAlign="middle"
        backgroundColor="white">

    <mx:Array id="filterArray">
        <flash.filters:DropShadowFilter id="dropShadowFilter"
                angle="90"
                blurX="5"
                blurY="5"
                  distance="2"
                  alpha="0.9"
                  color="0xFF0000" />
          <flash.filters:BlurFilter id="blurFilter"
                  blurX="3"
                  blurY="3"
                  quality="3" />
    </mx:Array>

    <mx:Label text="{flash.system.Capabilities.version}"
            fontSize="32"
            filters="{filterArray}" />

</mx:Application>

http://blog.flexexamples.com/

list-at-a-time in as3

package
{
    import fl.controls.List;
    import fl.data.DataProvider;
    import flash.display.MovieClip;
    public class ArrayFilterTest extends MovieClip
    {
        
        protected var original_ar:Array
        protected var filtered_ar:Array
        protected var mapped_ar:Array
        
        public function ArrayFilterTest()
        {
            trace( "[ArrayFilterTest] - ArrayFilterTest() :: Constructed." )
            
            original_ar = new Array()
            filtered_ar = new Array()
            mapped_ar = new Array()
            
            for( var i:uint = 0; i < 10; i ++ )
            {
                original_ar.push( new ArrayTestItem() )
            }
            
            trace( "[ArrayFilterTest] - ArrayFilterTest() :: Original array: " )
            original_ar.forEach( traceItem )
            
            trace( "[ArrayFilterTest] - ArrayFilterTest() :: Filtered array: " )
            filtered_ar = original_ar.filter( filterItems )
            filtered_ar.forEach( traceItem )
            
            trace( "[ArrayFilterTest] - ArrayFilterTest() :: Mapped array: " )
            mapped_ar = original_ar.map( mapItems )
            mapped_ar.forEach( traceItem )
        }
        
        private function traceItem( element:ArrayTestItem, index:int, arr:Array ):void
        {
            trace( index + "\t\t" + element.ID + "\t\t" + element.test )
        }
        
        private function filterItems( element:ArrayTestItem, index:int, arr:Array ):Boolean
        {
            return element.test
        }
        
        private function mapItems( element:ArrayTestItem, index:int, Array:Array ):ArrayTestItem
        {
            var e:ArrayTestItem = new ArrayTestItem()
            e.ID = element.ID
            e.test = false
            return e
        }
    }
}

class ArrayTestItem
{
    
    public var test:Boolean
    public var ID:Number
    public function ArrayTestItem()
    {
        test = Math.random() > 0.5
        ID = Math.floor( Math.random() * 1000 )
    }
}

http://eokyere.blogspot.com/