I’ve lost count on how many times I’ve needed this in RIA development with Flex or ActionScript: the possibility to quickly copy property values from one class instance to another. The two most important uses I can think of right now are these:
- You send a value object (VO) to the server. It comes back with a bunch of additional data. So far so good. But what you get back is another instance than the one you’ve just sent up the wire. Since the original instance may already be referenced somewhere in the application we do not want to simply replace it. We want the original instance filled with the new property values.
- You show the user a form with which he can edit a VO. After he’s changed some values he can either commit his changes (‘OK’ button) or discard them (‘cancel’ button). In this scenario you’ll usually keep a copy of the original VO somewhere handy because you want to be able to restore it when needed. Now the story is the same as the previous one: we want to restore the values of the original instance, not replace it entirely.
So I finally made this convenience method that uses describeType() for introspection as an addition to my
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22
A simple example:
1 2 3 4 5 6