Clipper - classes in Clipper

Author

classes in Clipper

Alan Secker

2005-09-09, 6:55 pm

Is their a syntax that Clipper recognises to support class creation.
I would like to modify a standardised array driven browse creation
system to a class structure. It would more smoothly support the
pluggable approach of OO. Something along the lines of

CLASS Rubbish Inherit tbrowse.

TIA

Rob

2005-09-09, 6:55 pm

Alan,
AFAIR, you can't create new classes etc. using Clipper alone. you would
have to get your hands on some thing like Class(y) or another third party
product to go fully OOP.

Regards,
Rob ( R&D Software, P/L )

Frank Demont

2005-09-10, 6:55 pm

Why not xharbour ? it is fully clipper compatible and can handle classes
perfectly.

Frank

"Alan Secker" <alan(delete this bit)@asandco.co.uk> schreef in bericht
news:pan.2005.09.09.22.08.53.838208@asandco.co.uk...
> Is their a syntax that Clipper recognises to support class creation.
> I would like to modify a standardised array driven browse creation
> system to a class structure. It would more smoothly support the
> pluggable approach of OO. Something along the lines of
>
> CLASS Rubbish Inherit tbrowse.
>
> TIA
>

frank van nuffel

2005-09-10, 6:55 pm

Hi Alan,

"Alan Secker" schreef
in bericht news:pan.2005.09.09.22.08.53.838208@asandco.co.uk...

> Is their a syntax that Clipper recognises to support class creation.
> I would like to modify a standardised array driven browse creation
> system to a class structure. It would more smoothly support the
> pluggable approach of OO. Something along the lines of

> CLASS Rubbish Inherit tbrowse.

In an article of way back 1994 Steve Steiner explains how to put
Clipper undocumented functions to use for creating one's own
classes, pretty much the way the GUI classes in Clipper 5.3 were
implemented

source: Clipper Advisor March/April 1994

Unfortunately, Clipper's native OO model never supported inheritance,
and especially inheriting from Clipper's standard classes did not fit in
this picture, but providing an object as an instance variable in an UDO
and having all messages for that object being delegated to that instance
var is a way out of this limitation; or, use the cargo slot of your TBrowse
object to hold your UDO

Otherwisely, check out Classy: --- from its norton guide ---

Casestudy: GET .oO haven't found one about TBrowse in the e-distrib

Because of the way in which inheritance from GET has been implemented,
access to instance variables in subclasses of GET is slower than it is for
other classes. In most cases, this is not noticeable. However, it can
become a problem with large or complex subclasses of GET. If that is the
case, a possible alternative to subclassing GET is to design a wrapper
class which contains a GET object as one of its instance variables, and
delegates all GET messages to that object. Of course, the performance gain
delegating all of GET's messages. The best solution depends on the
requirements of the application.

HTH

f

Alan Secker

2005-09-10, 6:55 pm

On Sat, 10 Sep 2005 14:30:53 +0200, Frank Demont wrote:
[color=darkred]
> Why not xharbour ? it is fully clipper compatible and can handle classes
> perfectly.
>
> Frank
>
> "Alan Secker" <alan(delete this bit)@asandco.co.uk> schreef in bericht
> news:pan.2005.09.09.22.08.53.838208@asandco.co.uk...

Hi Frank

I'm planning to do just that but I'm trying to run it under Linux and I've
got some 'Newbie' style problems concerning scripts, versions and
ALTD() and FiveLinux. If you have any experience of xHarbour under
Linux, can I bend your ear (so to speak)?

Regards

Alan

Sponsored Links