Empathy List Archives

JH

Jimmie Houchin

Tue, Dec 22, 2020 11:07 PM

Hello,

I have created a class which will have many subclasses some of which
will have subclasses of their own.

I want every single class to implement a class method #shortName which
will provide a short string as a human readable short identifier to the
object.

I have in the highest superClass

shortName

self subclassResponsibility

But the moment I implement it in a subclass which has subclasses. Those
subclasses are now using their closest superClasses implementation.

Is there a way force allSubclasses to implement the method?

Thanks.

Jimmie

Hello, I have created a class which will have many subclasses some of which will have subclasses of their own. I want every single class to implement a class method #shortName which will provide a short string as a human readable short identifier to the object. I have in the highest superClass shortName self subclassResponsibility But the moment I implement it in a subclass which has subclasses. Those subclasses are now using their closest superClasses implementation. Is there a way force allSubclasses to implement the method? Thanks. Jimmie

RS

Richard Sargent

Wed, Dec 23, 2020 2:01 AM

Is there a way force allSubclasses to implement the method?

No. Pretty much, you need to avoid subclassing concrete classes.
i.e. if A has subclasses B and C, refactor to create an abstract A' and move
A to be a leaf subclass of A'.

-----Original Message-----
From: Jimmie Houchin [mailto:jlhouchin@gmail.com]
Sent: December 22, 2020 15:08
To: Any question about pharo is welcome
Subject: [Pharo-users] subclassResponsibility

Hello,

I have created a class which will have many subclasses some of which will
have subclasses of their own.

I want every single class to implement a class method #shortName which will
provide a short string as a human readable short identifier to the object.

I have in the highest superClass

shortName

self subclassResponsibility

But the moment I implement it in a subclass which has subclasses. Those
subclasses are now using their closest superClasses implementation.

Is there a way force allSubclasses to implement the method?

Thanks.

Jimmie

Is there a way force allSubclasses to implement the method? No. Pretty much, you need to avoid subclassing concrete classes. i.e. if A has subclasses B and C, refactor to create an abstract A' and move A to be a leaf subclass of A'. -----Original Message----- From: Jimmie Houchin [mailto:jlhouchin@gmail.com] Sent: December 22, 2020 15:08 To: Any question about pharo is welcome Subject: [Pharo-users] subclassResponsibility Hello, I have created a class which will have many subclasses some of which will have subclasses of their own. I want every single class to implement a class method #shortName which will provide a short string as a human readable short identifier to the object. I have in the highest superClass shortName self subclassResponsibility But the moment I implement it in a subclass which has subclasses. Those subclasses are now using their closest superClasses implementation. Is there a way force allSubclasses to implement the method? Thanks. Jimmie

JH

Jimmie Houchin

Wed, Dec 23, 2020 2:57 PM

I didn't thinks so, but was not sure.

I have not done much with Abstract classes. I will have to think about
that and its design implications.

Thanks for the suggestion.

Jimmie

On 12/22/20 8:01 PM, Richard Sargent wrote:

Is there a way force allSubclasses to implement the method?

No. Pretty much, you need to avoid subclassing concrete classes.
i.e. if A has subclasses B and C, refactor to create an abstract A' and move
A to be a leaf subclass of A'.

-----Original Message-----
From: Jimmie Houchin [mailto:jlhouchin@gmail.com]
Sent: December 22, 2020 15:08
To: Any question about pharo is welcome
Subject: [Pharo-users] subclassResponsibility

Hello,

I have created a class which will have many subclasses some of which will
have subclasses of their own.

I want every single class to implement a class method #shortName which will
provide a short string as a human readable short identifier to the object.

I have in the highest superClass

shortName

self subclassResponsibility

But the moment I implement it in a subclass which has subclasses. Those
subclasses are now using their closest superClasses implementation.

Is there a way force allSubclasses to implement the method?

Thanks.

Jimmie

I didn't thinks so, but was not sure. I have not done much with Abstract classes. I will have to think about that and its design implications. Thanks for the suggestion. Jimmie On 12/22/20 8:01 PM, Richard Sargent wrote: > Is there a way force allSubclasses to implement the method? > > No. Pretty much, you need to avoid subclassing concrete classes. > i.e. if A has subclasses B and C, refactor to create an abstract A' and move > A to be a leaf subclass of A'. > > -----Original Message----- > From: Jimmie Houchin [mailto:jlhouchin@gmail.com] > Sent: December 22, 2020 15:08 > To: Any question about pharo is welcome > Subject: [Pharo-users] subclassResponsibility > > Hello, > > I have created a class which will have many subclasses some of which will > have subclasses of their own. > > I want every single class to implement a class method #shortName which will > provide a short string as a human readable short identifier to the object. > > I have in the highest superClass > > > shortName > > self subclassResponsibility > > > But the moment I implement it in a subclass which has subclasses. Those > subclasses are now using their closest superClasses implementation. > > Is there a way force allSubclasses to implement the method? > > > Thanks. > > > Jimmie

pharo-users@lists.pharo.org

subclassResponsibility