Yesterday I struggled for several hours looking in the Livecycle Data Services code in order to investigate the following error message:TypeError: Error #1034: Type Coercion failed: cannot convert “ZGUID” to QName. It was not easy but in the end I understood that it is an issue related to property collision inside of the ManagedObjectProxy  class. The ManagedObjectProxy instance is adding all the properties from the serialized objects into it. However if the name of one of your properties already exists in the ManagedObjectProxy instance then this process will fail. The following properties already exist (inherited from ObjectProxy):

dispatcher : EventDispatcher
notifiers : Object
object : Object
propertyList : Array
proxyClass : Class
type : QName
uid:String

For the “type” property a fix was provided in Livecycle Data Services 3, but not for the others. So if you design your domain object and you plan to use Livecycle Data Services it’s a good idea to not use this reserved keywords as names for your properties.

The problem appears only if you like to use the proxy approach (not having the corresponding AS class included in the client SWF).

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Original article at http://cornelcreanga.com/2009/12/lcds-managedobjectproxy-and-some-reserved-keywords/.