Inheritance and Shared Methods

[Joe Fallon]

1. I have a Base class that has a certain amount of functionality.
2. Then I have a CodeSmith generated class that inherits from the Base class
and adds functionality.
3. Since I want to be able to re-generate the classes on level 2 I have a
3rd level that inherits from them and implements specific hand coded
methods.
4. My colleague asked me to create a 4th level class that inherits the 3rd
level class so he can write custom functionality that overrides the "plain"
functionality at all levels above it.

I have 1-3 implemented as Shared methods.
To me, this enables simpler UI code.

For example:
strSQL = Level3ClassName .Select

In this way I do not need to instantiate an instance of the class I just use
the shared methods in levels 1-3.

=============== =============== =============== ==============
My problem (other than being new and not really understanding this well
enough yet <g> )
is I don't know how to implement Level 4 in a way that allows me to use
Shared methods in levels1-3 and yet Override them in Level 4.

Is it not possible?
=============== =============== =============== =============== ==

If I have to change Levels 1-3 what would you recommend?

=============== =============== =============== ===

Sample code:

Level 1
Public MustInherit Class Base

Public Shared Function DoSomething(ByV al Source As String) As String

End Function
=============== =============== =============== ===
Level 2
Public MustInherit Class GeneratedStuff

Inherits Base

Public Shared Function DoSomethingElse (ByVal Source As String) As String

End Function
=============== =============== =============== ===
Level 3
Public MustInherit Class HandCodedStuff

Inherits GeneratedStuff

Public Shared Function IWroteThis(ByVa l Source As String) As String

End Function
=============== =============== =============== ===
Level 4 (implements same functionality as Level 3 but also allows customized
changes by overriding methods or creating new ones that are specific to a
single client. Level 3 functionality is for all clients.)
Public MustInherit Class FinalLevel

Inherits HandCodedStuff

Overrides Function DoSomethingElse (ByVal Source As String) As String

End Function

Thanks for any advice!
--
Joe Fallon

[Joe Fallon]

I just got back from a business trip and this is the first chance I have had
to look at this thread.

I would like to thank all of you for providing me with so much information.

I won' t be able to test it for a few days but I am leaning towards the use
of Shadows right now.
It may be good enough but I am not 100% sure.

I do have a Singleton class so I am familiar with that concept.
(I use it for Read/Write app settings.)

I am looking for a way to use the Shared methods and still give my co-worker
the ability to get a custom behavior in the 4th level. (We would "never"
call directly into levels 1,2 3.)

I am sure I will be back with more questions!
Thanks again for the spirited discussion.
--
Joe Fallon
"Fergus Cooney" <fi*****@post.c om> wrote in message
news:e0******** ******@TK2MSFTN GP09.phx.gbl...

Hi Joe,

If you want to keep your methods as Shared then you can't use Overrides in Level 4. Overrideable and Overrides are only available with object methods, so that would be goodbye to your Shared..

There is, however, the option of using Shadows. In FinalLevel,
Shadows Function DoSomethingElse (...) As String
will make the name DoSomethingElse available to users of that class.

If you were doing this using object methods and Overrides, you would call the base class method using MyBase.SameMeth od as Scott pointed out.

With Shared methods the equivalent is simply to use the name of the base class.

So you could have:
'Level 2
Public MustInherit Class GeneratedStuff
Inherits Base
Public Shared Function DoSomethingElse (...) As String
End Function
End Class

'Level 4
Public MustInherit Class FinalLevel_Clie nt1
Inherits HandCodedStuff
Shadows Public Shared Function DoSomethingElse (...) As String
GeneratedStuff. DoSomethingElse (...) 'If necessary:
'Do Client1's something else.
End Function
End Class

'Ditto for Client2, etc.

Regards,
Fergus

[Joe Fallon]

Initial testing shows that Shadows does what I am looking for!

In my 4th level class I can opt to "do nothing" in which case I get the
standard functions available in the 3 levels above it. But if I want to
replace specific functionality with "custom" code I can use syntax like
this:

Public Shared Shadows Function DoSomething() As String
Return "Custom String"

End Function

I think this will work for me.
So thanks again to all for their input!
--
Joe Fallon

"Joe Fallon" <jf******@nospa mtwcny.rr.com> wrote in message
news:%2******** ********@TK2MSF TNGP10.phx.gbl. ..

I just got back from a business trip and this is the first chance I have had to look at this thread.

I would like to thank all of you for providing me with so much information.
I won' t be able to test it for a few days but I am leaning towards the use of Shadows right now.
It may be good enough but I am not 100% sure.

I do have a Singleton class so I am familiar with that concept.
(I use it for Read/Write app settings.)

I am looking for a way to use the Shared methods and still give my co-worker the ability to get a custom behavior in the 4th level. (We would "never"
call directly into levels 1,2 3.)

I am sure I will be back with more questions!
Thanks again for the spirited discussion.
--
Joe Fallon
"Fergus Cooney" <fi*****@post.c om> wrote in message
news:e0******** ******@TK2MSFTN GP09.phx.gbl...

Hi Joe,

If you want to keep your methods as Shared then you can't use

Overrides in

Level 4. Overrideable and Overrides are only available with object

methods, so

that would be goodbye to your Shared..

There is, however, the option of using Shadows. In FinalLevel,
Shadows Function DoSomethingElse (...) As String
will make the name DoSomethingElse available to users of that class.

If you were doing this using object methods and Overrides, you would

call

the base class method using MyBase.SameMeth od as Scott pointed out.

With Shared methods the equivalent is simply to use the name of the

base

class.

So you could have:
'Level 2
Public MustInherit Class GeneratedStuff
Inherits Base
Public Shared Function DoSomethingElse (...) As String
End Function
End Class

'Level 4
Public MustInherit Class FinalLevel_Clie nt1
Inherits HandCodedStuff
Shadows Public Shared Function DoSomethingElse (...) As String GeneratedStuff. DoSomethingElse (...) 'If necessary:
'Do Client1's something else.
End Function
End Class

'Ditto for Client2, etc.

Regards,
Fergus

[Fergus Cooney]

;-))

[scorpion53061]

Fergus,

Please see the thread entitled "Ole Container" and if you have input please
help.....

"Fergus Cooney" <fi*****@post.c om> wrote in message
news:OY******** ******@TK2MSFTN GP12.phx.gbl...

;-))