Richard Rodseth wrote:
> Has anyone done the work to enhance Darron Schall's ObjectTranslator
> class to work recursively, as he describes in the source code?
>
> In the absence of that, I was think of adding static factory methods
> to my VO objects, as follows:
>
> static public function newInstanceFromJSON(json : String) : StudentVO {
> var student:Object = JSON.decode( json ); var
> studentVO:StudentVO =
> ObjectTranslator.objectToInstanc(student,StudentVO);
>
> for ( var i:int = 0; i < studentVO.books.length; i++ )
> {
> var bookVO:BookVO = ObjectTranslator.objectToInstance(
> studentVO.books[i], BookVO ) as BookVO;
> // Use the converted class instance in place of the regular
> object
> studentVO.books[i] = bookVO;
> }
> return studentVO;
> }
>
> Comments welcome.
>
I use a return type of array to obtain a dynamic object(DO) object graph
from a HTTPService call that returns xml. I pass the result object to
the top most VO, which then inits the graph of VO objects(using factory
methods).
The DO is adapted/proxied/decorated by the VO so there is no copying of
data from dynamic to strongly typed; the functions calls are proxied to
the DO.
This provides a lot of control and has a few benefits for me:
. Able to access and use the internal dynamic object if required without
making the VO class dynamic.
. Generated "_Classes" make changes to xml returned from server very
easy to manage. New properties or event handlers etc. can easily be
added to all model objects.
. Able to use the internal dynamic object to JSON encode the
return(POST) data.
. Use of strongly typed objects within AS and mxml.
. Conversion from booleans to "Y", "N", "A" "I" (yes/no/active/inactive)
values or Dates to String types is straight forward.
Eg)
class XYZ extends _XYZ{
//xyz has many abc objects.
private abcObjects:ArrayCollection;
//called on result of a http service invocation
public static function newInstance(rootObj:Object):XYZ{
//create and return an instance of XYZ.
//init the children objects by calling there factory function
var obj:XYZ = new _XYZ(rootObj);
obj.initABCObjects();
return obj;
}
protected function initABCObjects():void{
abcObjects = new ArrayCollection();
if (super.oData.abcObjects){
//loop creating and adding to abcObjects using
//ABC.newInstance(abcObjects[i]);
}
}
}
//perl generated AS class contains functions to access simple properties
// complex properties of VO's are handled in the subclass.
class _XYZ {
private var _o:Object;
public function _XYZ(o:Object){
_o = o;
}
public function get oData():Object{
return _o;
}
public function getName():String{
return _o.name;
}
public function setName(name:String):void{
_o.name = name;
}
}
There are probably better ways to do this but I've had reasonable
success to-date with the approach described above. The generated code
really makes it easy when things are constantly changing during development.
regards,
- shaun
