Re: [Help-smalltalk] Code update and class variables

[Paolo Bonzini]

On Mon, Sep 6, 2010 at 09:11, Holger Hans Peter Freyther
<address@hidden> wrote:
> Hi all,
>
> I am currently 'porting' (redoing) the OpenBSC/Osmocom logging framework in
> Smalltalk and while developing I see that I have one question/issue with
> updating the code.
>
> I have a LogArea which is a three tuple of (description, enabled, minLevel), I
> have a LogConfig that holds a list of areas and gives them local names.
>
> So I have something like:
>
> Object subclass: LogConfig [
>        Config := LogConfig new.
>
>        LogConfig class >> default [
>                ^ Config
>        ]
>
>        addArea: anArea name: aName [
>                addInstanceVariableAndSetIt
>                GenerateGetMethod...
>        ]
> ]
>
> and in another Package/Namespace I would do..
>
> log.LogConfig defaut addArea: localArea: #localName..

Passing note: namespaces are usually capitalized.

> Now I have two issues:
>        1.) 1 to 3: [SomeClass class addInstVarName: #boo], will add #boo
>            three. Is that a bug? That should not be possible, bad things
>            will happen as a result..

It's a bit ugly, but not strictly a bug.  I suggest you use a
dictionary, and #doesNotUnderstand: instead of a getter, especially
because you're adding the instance variables to _all_ instances of
LogConfig rather than just one.

>        2.) FileStream fileIn: 'Log.st'. will set Config back to a new
>            instance of LogConfig and all added areas are gone. What are the
>            workarounds? Put Config into the Smalltalk dict? Use Notifications
>            so people can add their areas again?

This would be fixed by using a dictionary and #doesNotUnderstand:, too.

Paolo