Hi Mark In the fairly large applications I've worked on, I've not had occasion to use Proxy, if you mean this:
http://livedocs.adobe.com/flex/3/langref/flash/utils/Proxy.html Basically it lets you create an object that poses as something else, possibly supplementing it. For example, in the example given, they create a ProxyArray which actually derives from Proxy, but (dynamically) implements the properties, operators and methods of Array, adding sum() and clear() methods. Others may disagree, and I'd love to hear of good examples, but I would actually think twice before using this. You're sacrificing type safety and possibly performance. On the other hand, Value Objects (closely related to DTOs [Data Transfer Objects], and to be contrasted with Entity objects), are bread and butter things. http://c2.com/cgi/wiki?ValueObject "Their identity is based on their state rather than on their object identity. This way, you can have multiple copies of the same conceptual value object" i.e. two Date instances with the same day, month etc. represent the same date, whereas var employee:Employee might refer to different Employee instances at different times, in which case we're talking about different Employees. In a Flex app, VOs are typically created to represent "messages". Your API (whether AMF, JSON or XML) will return flattened data which is then converted into an object instance tree structure (not to be confused with a class inheritance tree, if you're new to OOP). If you are creating these VO classes yourself (as opposed to using ones whose source is generated by tools provided by LiveCycle, WebOrb etc) you should resist the impulse to add "business logic" to them. They'll typically have nothing more than a few public properties. So you might have both an EmployeeVO and an Employee class, where EmployeeVO is a Value Object or DTO, and Employee is an entity. Hope this helps. I'm sure others will weigh in. - Richard P.S. It's perhaps more appropriate to server-side work, but I love Eric Evans' book on Domain-Driven-Design http://domaindrivendesign.org/ On Thu, Jul 22, 2010 at 2:52 PM, mark.embrey <mark.c.emb...@gmail.com>wrote: > > > I'm trying to wrap my feeble brain around these concepts. > > Are they the same? -similar? -completely different? > > Your feedback will be appreciated by this greenhorn. > > Mark > > >
