Actionscript 3 Flex 4.5 Serialization/Deserialization issue? - actionscript-3

Question

I'm having a particular issue deserializing an object in a Flex 4.5 Mobile project. I've connected to a Webservice fine and populate a ListBox fine. I can select the item and get the details just fine as well but after serializing the object and trying to deserialize it; the Object definition is getting lost somewhere.
I have a variable for when the user selected the request in a List
private var selectedReq:ServiceRequest;
//Here we instantiate the local variable when user select id in ListBox
selectedReq = event.currentTarget.selectedItem as ServiceRequest;
Each Service Request the user chooses to save will call this method.
private function writeServiceRequest():void {
var filename:String = buildFileName();
var file:File = File.applicationStorageDirectory.resolvePath(filename);
if (file.exists)
file.deleteFile();
var fileStream:FileStream = new FileStream();
fileStream.open(file, FileMode.WRITE);
//selectedReq is the private var of the users selected item
fileStream.writeObject(selectedReq);
fileStream.close();
}
When the users want to view the request this method is called.
private function readServiceRequest():ServiceRequest {
var filename:String = buildFileName();
var file:File = File.applicationStorageDirectory.resolvePath(filename);
if (!file.exists) {
return null;
}
var fileStream:FileStream = new FileStream();
fileStream.open(file, FileMode.READ);
var objReq:ServiceRequest = fileStream.readObject() as ServiceRequest;
fileStream.close();
return objReq;
}
The Class Object is similar to.
public var id:uint;
public var requisitioner:String;
public var requestItems:ArrayCollection //Webservice it's actually List<requestItems>
public var requestProcesses:ArrayCollection // WSDL it's actually List<>
When I try to read/deserialize like
//This line is null but the file exist and the object was written
var objReq:ServiceRequest = readServiceRequest() as ServiceRequest;
if(objReq) {
selectedReq = objReq;
}
If I do not cast the readServiceRequest() as ServiceRequest and simply return an Object; I can iterate through the Object and get the correct values returned from the serialized object.
I can only assume the Classes that Flex created from the Webservice may be causing this? If the values are getting written but not the object type then something has to be lost in the serialization - correct?
Sorry for all the details but I'm a little lost at this time.....any help would be appreciated.
RL

Answer 1

var objReq:ServiceRequest = readServiceRequest() as ServiceRequest;
The above line will continue to return null.
I bet that if you modify it in the following way:
var objReq:ServiceRequest = ServiceRequest(readServiceRequest());
You'll get a run-time exception with a message similar to Can't cast ObjectProxy to ServiceRequest
If that's the case, then the reason you get this is because the AMF serializer doesn't preserve the type information when serializing the ServiceRequest-instance.
In order to fix this you need to call flash.net.registerClassAlias() before the serialization/deserialization.
flash.net.registerClassAlias("fully.qualified.name.ServiceRequest", ServiceRequest);

Answer 2

Try if this work.
Check if event.result is ByteArray.
Read/store the event.result as ByteArray.
var byteArray:ByteArray = event.result as ByteArray;
Get/Deserialize Object using readObject() function.
var object:Object = byteArray.readObject();
Cast to targetted object type. ServiceRequest in your case.
var tartgettedObject:ServiceRequest = object as ServiceRequest;
or
var tartgettedObject:ServiceRequest = ServiceRequest(object);

Answer 3

My bad for not signing in before posting the question.
I did use registerClassAlias which did not help. I did find on the Adobe forum other simular issues and the constant feedback was the problem is most likely caused by the Object Class loosing it's attributes during the file write reason being the Class Objects are written when the Datasource is created from the Webservice. Since my original question we decided to use SQLite which is working perfectly fine - thanks for all you help.
RL