On May 13, 2006, at 4:03 PM, Norman Palardy wrote:
On May 13, 2006, at 1:24 PM, Phil M wrote:
A Computed Property does not have it's own storage for the
value... so you have to have a real property backing it in some way.
What I like to do is use Computed Properties to "forward"
properties of embedded classes or controls. In the case of
ContainerControls, I forward properties of controls that I would
like to edit directly... like TextFont and TextSize for an
embedded EditField control. Another use is that I like combining
private properties into a Dictionary instance and then provide
access to these properties via Computed Properties.
In my opinion, Computed Properties are most useful when something
needs to happen when the value changes. For example if you have a
BackgroundColor property for a custom control, you will need to
redraw the control to reflect the change.
As an aside these are all things that can be done with a pair of
regular methods.
About the only "advantage" a computed property has over a pair of
methods is that it can be viewed in the debugger.
The pair of methods is equally flexible, and an be back used in
v5.5 while a computed property cannot.
I can't think of any other advantage a computed property has.
They cannot be overridden.
Charles Yeomans
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