patterns that apply when software treatments depends on data kind

[Olivier STEINBERG]

Hello, I'm facing a traditional problem on how to model objects when
the treatments depends on data kind.

For instance we have customers and price lists. The pricing strategy
is an algorythm specific to each custormer or group of customers.

My question is, is there a specific pattern that answer that kind of
problem ?
How to attach some method to a specific instance of a class ?

Any idea or clue would be appreciated.

Thank's


Olivier

[Joshua Frank]

If you mean how do you model this in software, I think the standard
answer would be to use inheritance. In pseudo VB code:

Class Customer
Function GetPrice() As Integer
'do calculation
End Function
End Class

Class ThisCustomer
Inherits Customer

Overrides Function GetPrice() As Integer
'do calculation specific to this customer
End Function
End Class

On the other hand, if there are lots of customers, this gets unwieldy,
and you would probably need to make it table driven and keep it in the
Customer class.

Olivier STEINBERG wrote:

> Hello, I'm facing a traditional problem on how to model objects when
> the treatments depends on data kind.
>
> For instance we have customers and price lists. The pricing strategy
> is an algorythm specific to each custormer or group of customers.
>
> My question is, is there a specific pattern that answer that kind of
> problem ?
> How to attach some method to a specific instance of a class ?
>
> Any idea or clue would be appreciated.
>
> Thank's
>
>
> Olivier

[Doug Pardee]

olivier@stelog.com (Olivier STEINBERG) wrote:
> Hello, I'm facing a traditional problem on how to model objects when
> the treatments depends on data kind.
>
> For instance we have customers and price lists. The pricing strategy
> is an algorythm specific to each custormer or group of customers.
>
> My question is, is there a specific pattern that answer that kind of
> problem ?

You already answered your own question, but didn't notice it:

> The pricing strategy is an algorythm specific to each custormer
========

The Strategy pattern handles this.