[Pharo-users] Updating a project and NIL class variables

Dimitris Chloupis kilon.alios at gmail.com
Wed Jan 20 09:34:20 EST 2016


Thank you for the info but I think I did not make myself clear because you
say "remain nil"

Ok Imagine a class SomeClass and that class has a variable we will call
SomeVariable, class variable that is
, there is no class initialize method, now that class has a method that is
eventually called ,
someMethod

SomeVariable ifNil: [ SomeVariable := 'hello world']

so when I decide to update this class via metacello loading the latest
version from github ,  SomeVariable will have the value 'hello world'

My question is , will SomeVariable after I do the update revert back to
nil  or stay 'hello world' ?

If your answer is no, and it stays 'hello world' then yes i need an
initialize method and call it at update time.

On Wed, Jan 20, 2016 at 2:54 PM Sven Van Caekenberghe <sven at stfx.eu> wrote:

> They remain nil.
>
> That is why #initialize on the class side is needed.
>
> You can call that explicitly in a post load script, or rely on the class
> loading mechanism that normally calls #initialize automatically when
> loading a class. The warning is: this only happens when the *source* code
> of the #initialize methods changes. So sometimes, you will have to touch
> that method to force it.
>
> I hope that makes sense.
>
> See MCMethodDefinition>>#postloadOver:
>
> > On 20 Jan 2016, at 13:41, Dimitris Chloupis <kilon.alios at gmail.com>
> wrote:
> >
> > So my question is this , I have a class with nil variables that are lazy
> initialised only when needed the first time and of course they keep their
> values from there on.
> >
> > Lets say I get the latest update from github via metacello over an older
> update that I already have inside the image , do those variables revert
> back to nil values ? or do they keep their values as they are ?
>
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.pharo.org/pipermail/pharo-users_lists.pharo.org/attachments/20160120/cae18aad/attachment.html>


More information about the Pharo-users mailing list