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

[Fergus Cooney]

Hi Cor,

LOL.

Different interpretations .

'Study a bit more, please'
The speaker is demanding.
I want you to do something.

'I suggest that you study a bit more.'
The speaker is offering.
Here's something you could do.
It's up to you.

That's the 'being-correct-about-English' version.

In the current emotional context, if I added 'please' I would be offering
sarcastic and insincere politeness as shown in that other message. I was
merely being 'pointed' in my tone.

But I believe I hear what you are saying, Cor - "why not start to mend the
rift". It's a worthy suggestion but one that will take some time. It's much
too early for HK and I'm not quite ready yet either.

Regards,
Fergus

[Fergus Cooney]

Herfried,

I will continue to correct you when you make ridiculous statements about
me. It would be much better for everyone if you expressed your various angers
in the threads which have been previously taken over.

You are being very inconsiderate in using Joe Fallon's thread (and others)
to mouth off. It's fine when the OP has been answered and gone their way -
then you can treat a thread as you like. Until then it is much more respectful
to the OP, and everyone else, if you place your emotional OT words in the
fighting areas provided.

=============== ======
Keep it out of the mainstream.
=============== ======

Fergus

[Herfried K. Wagner [MVP]]

* "Fergus Cooney" <fi*****@post.c om> scripsit:
[...]

Please email me things like that and do not annoy the community by your
spam posts. Just remove the "spam-me-here" part of my mail address and
reply to it instead of destroying the group.

--
Herfried K. Wagner
MVP · VB Classic, VB.NET
<http://www.mvps.org/dotnet>

[Fergus Cooney]

Take this to the other thread.

[Scott M.]

Not ignoring, but don't see any reply from you at all to this message prior
to mine. So, thanks for the attitude.

"Fergus Cooney" <fi*****@post.c om> wrote in message
news:ux******** ******@TK2MSFTN GP10.phx.gbl...

Hi Scott,

If you are ignoring my posts, you won't have seen that I recommended using Shadows in this case.

Regards,
Fergus

[Scott M.]

Thanks Jay. I am aware of how OverRides and Shadows work (which is why I
suggested Shared in my second reply). I was just unaware that a class
member couldn't be marked as both Shared and OverRideable.

As for the rest of the bickerring in this thread, let me just say that I
don't see anything from Fergus on Shadows prior to my reply to Joe's
question, so I'm sorry if I repeated what he said.
"Jay B. Harlow [MVP - Outlook]" <Ja********@ema il.msn.com> wrote in message
news:O2******** ********@TK2MSF TNGP10.phx.gbl. ..

Scott,
As Fergus stated, he wrote up a little something on Shadows.

The problem is that Shadows does not Override functionality. Shadows Hides
functionality.

If you used Shadows and referred to the base class you will get the base
class functionality. The way I read Joe's comments, he wants to override the base class functionality, in that he could refer to the base class and see
the replaced functionality.

Don't get me wrong you can use Shadows in a situation like this, and in some ways its the "easiest" thing to use in Joe's case. However just be certain
you know what Shadows is giving you & not giving you.

For a sample of how to use Overrides in Joe's case, see my other long post
to this thread.

Hope this helps
Jay

"Scott M." <s-***@badspamsnet .net> wrote in message
news:Oo******** ******@TK2MSFTN GP09.phx.gbl...

What about Shadows then?
"Jay B. Harlow [MVP - Outlook]" <Ja********@ema il.msn.com> wrote in

message

news:ut******** ******@TK2MSFTN GP09.phx.gbl...

Scott,
Overrides & Shared are incompatible. You can only override Overridable
methods. Overridable methods cannot be Shared.

Hope this helps
Jay

"Scott M." <s-***@badspamsnet .net> wrote in message
news:uv******** *****@TK2MSFTNG P11.phx.gbl...
> I would think that in the 4th class if you wanted to use the shared
methods
> from classes 1-3, you would say "myBase.met hod" and in the 4th class you > could define an Overrides method that overrides the shared method in the > base class.
>
>
> "Joe Fallon" <jf******@nospa mtwcny.rr.com> wrote in message
> news:%2******** ********@TK2MSF TNGP11.phx.gbl. ..
> > 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
> >
> >
> >
> >
>
>

[Fergus Cooney]

Hi Scott,

I think the apologies are mine. My message reads terribly on second look.
I meant to say that the answer to your question was yes and that there was
more information in my other post. The ignoring idea crept in and the wording
turned out badly. Sorry about that.

Regards,
Fergus

[Jay B. Harlow [MVP - Outlook]]

Scott,
Looking at the dates & times, Fergus's response was about 45 minutes after
your response, So when you gave your initial response it was not yet
available. My response was about 12 hours later, so I saw both of your
responses.

question, so I'm sorry if I repeated what he said. I would not worry about it. My comments are not meant to degrade or insult,
and I attempt to avoid "static". I referenced Fergus's response as I saw his
response and I did not want to duplicate the information for you. As at that
point in time, you could have simply read Fergus's response.
I was just unaware that a class
member couldn't be marked as both Shared and OverRideable. A number of developers have been asking for the ability, I believe a fair
share of these developers are coming from Delphi, as I am only really aware
of Delphi has the ability. I see value it allowing it, however my concern is
It raises the bar yet again of how much you really need to know to be an
effective .NET programmer. As oppose to "being little kids" and either
avoiding the features of .NET or abusing the features. Because they either
don't understand the feature or you don't know the feature exists. Or worse,
"we did it this way in VB6, so obviously we can do it the sam way in
VB.NET".

I have not seen anything in the road map that would suggest we are getting
it in VS.NET 2004.

Hope this helps
Jay

"Scott M." <s-***@badspamsnet .net> wrote in message
news:%2******** *******@TK2MSFT NGP12.phx.gbl.. . Thanks Jay. I am aware of how OverRides and Shadows work (which is why I
suggested Shared in my second reply). I was just unaware that a class
member couldn't be marked as both Shared and OverRideable.

As for the rest of the bickerring in this thread, let me just say that I
don't see anything from Fergus on Shadows prior to my reply to Joe's
question, so I'm sorry if I repeated what he said.
"Jay B. Harlow [MVP - Outlook]" <Ja********@ema il.msn.com> wrote in message news:O2******** ********@TK2MSF TNGP10.phx.gbl. ..

Scott,
As Fergus stated, he wrote up a little something on Shadows.

The problem is that Shadows does not Override functionality. Shadows Hides

functionality.

If you used Shadows and referred to the base class you will get the base
class functionality. The way I read Joe's comments, he wants to override the

base class functionality, in that he could refer to the base class and see the replaced functionality.

Don't get me wrong you can use Shadows in a situation like this, and in

some

ways its the "easiest" thing to use in Joe's case. However just be certain you know what Shadows is giving you & not giving you.

For a sample of how to use Overrides in Joe's case, see my other long post to this thread.

Hope this helps
Jay

"Scott M." <s-***@badspamsnet .net> wrote in message
news:Oo******** ******@TK2MSFTN GP09.phx.gbl...

What about Shadows then?
"Jay B. Harlow [MVP - Outlook]" <Ja********@ema il.msn.com> wrote in

message

news:ut******** ******@TK2MSFTN GP09.phx.gbl...
> Scott,
> Overrides & Shared are incompatible. You can only override Overridable > methods. Overridable methods cannot be Shared.
>
> Hope this helps
> Jay
>
> "Scott M." <s-***@badspamsnet .net> wrote in message
> news:uv******** *****@TK2MSFTNG P11.phx.gbl...
> > I would think that in the 4th class if you wanted to use the shared > methods
> > from classes 1-3, you would say "myBase.met hod" and in the 4th class

you

> > could define an Overrides method that overrides the shared method

in the

> > base class.
> >
> >
> > "Joe Fallon" <jf******@nospa mtwcny.rr.com> wrote in message
> > news:%2******** ********@TK2MSF TNGP11.phx.gbl. ..
> > > 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
> > >
> > >
> > >
> > >
> >
> >
>
>

[Scott M.]

Thanks Jay.
"Jay B. Harlow [MVP - Outlook]" <Ja********@ema il.msn.com> wrote in message
news:OB******** ******@TK2MSFTN GP09.phx.gbl...

Scott,
Looking at the dates & times, Fergus's response was about 45 minutes after
your response, So when you gave your initial response it was not yet
available. My response was about 12 hours later, so I saw both of your
responses.

question, so I'm sorry if I repeated what he said. I would not worry about it. My comments are not meant to degrade or

insult, and I attempt to avoid "static". I referenced Fergus's response as I saw his response and I did not want to duplicate the information for you. As at that point in time, you could have simply read Fergus's response.

I was just unaware that a class
member couldn't be marked as both Shared and OverRideable. A number of developers have been asking for the ability, I believe a fair
share of these developers are coming from Delphi, as I am only really

aware of Delphi has the ability. I see value it allowing it, however my concern is It raises the bar yet again of how much you really need to know to be an
effective .NET programmer. As oppose to "being little kids" and either
avoiding the features of .NET or abusing the features. Because they either
don't understand the feature or you don't know the feature exists. Or worse, "we did it this way in VB6, so obviously we can do it the sam way in
VB.NET".

I have not seen anything in the road map that would suggest we are getting
it in VS.NET 2004.

Hope this helps
Jay

"Scott M." <s-***@badspamsnet .net> wrote in message
news:%2******** *******@TK2MSFT NGP12.phx.gbl.. .

Thanks Jay. I am aware of how OverRides and Shadows work (which is why I

suggested Shared in my second reply). I was just unaware that a class
member couldn't be marked as both Shared and OverRideable.

As for the rest of the bickerring in this thread, let me just say that I
don't see anything from Fergus on Shadows prior to my reply to Joe's
question, so I'm sorry if I repeated what he said.
"Jay B. Harlow [MVP - Outlook]" <Ja********@ema il.msn.com> wrote in message

news:O2******** ********@TK2MSF TNGP10.phx.gbl. ..

Scott,
As Fergus stated, he wrote up a little something on Shadows.

The problem is that Shadows does not Override functionality. Shadows Hides functionality.

If you used Shadows and referred to the base class you will get the base class functionality. The way I read Joe's comments, he wants to

override the

base class functionality, in that he could refer to the base class and see the replaced functionality.

Don't get me wrong you can use Shadows in a situation like this, and

in some

ways its the "easiest" thing to use in Joe's case. However just be certain you know what Shadows is giving you & not giving you.

For a sample of how to use Overrides in Joe's case, see my other long post to this thread.

Hope this helps
Jay

"Scott M." <s-***@badspamsnet .net> wrote in message
news:Oo******** ******@TK2MSFTN GP09.phx.gbl...
> What about Shadows then?
>
>
> "Jay B. Harlow [MVP - Outlook]" <Ja********@ema il.msn.com> wrote in
message
> news:ut******** ******@TK2MSFTN GP09.phx.gbl...
> > Scott,
> > Overrides & Shared are incompatible. You can only override Overridable > > methods. Overridable methods cannot be Shared.
> >
> > Hope this helps
> > Jay
> >
> > "Scott M." <s-***@badspamsnet .net> wrote in message
> > news:uv******** *****@TK2MSFTNG P11.phx.gbl...
> > > I would think that in the 4th class if you wanted to use the shared > > methods
> > > from classes 1-3, you would say "myBase.met hod" and in the 4th class you
> > > could define an Overrides method that overrides the shared

method in the
> > > base class.
> > >
> > >
> > > "Joe Fallon" <jf******@nospa mtwcny.rr.com> wrote in message
> > > news:%2******** ********@TK2MSF TNGP11.phx.gbl. ..
> > > > 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
> > > >
> > > >
> > > >
> > > >
> > >
> > >
> >
> >
>
>

[Scott M.]

No problem Fergus. Thanks.
"Fergus Cooney" <fi*****@post.c om> wrote in message
news:eq******** ********@TK2MSF TNGP10.phx.gbl. ..

Hi Scott,

I think the apologies are mine. My message reads terribly on second look. I meant to say that the answer to your question was yes and that there was
more information in my other post. The ignoring idea crept in and the wording turned out badly. Sorry about that.

Regards,
Fergus