17 May
2005
17 May
'05
3:08 p.m.
On 13.05.2005, at 14:38, stéphane ducasse wrote:
>
>> For the refactoring of pages we need to know the (direct) parent of
>> each SW2WikiObject (especially SW2DocumentItem subclasses).
>> SW2WikiObject has the instance variable owner, but it is not always
>> used.
>> We thought it would may be of general interest to always have this
>> attribute. Would it be possible to get this feature?
>
> In my opinion, back-links are generally a bad thing and therefor I
> try to avoid them whenever possible. Have a look at the i-var parent
> in SW2Structure and SW2Decoration and all the hassle around this.
> Back-links duplicate information and it makes several things, such as
> copying, more difficlut.
As far as we know, DocumentItem matches a composite pattern. Most
composite patterns do have parent links (e.g. Java AWT and there seems
no problem).
>
> Actually, while traversing a composite with a visitor you have given
> all the parent nodes implicilty in the context-stack. I don't suggest
> that you are using the context, but to keep the last node in an i-var
> or build up a stack of the current path to your visited nodes.
I'm not that sure because in a AST having a back
pointer can save you
a lot of work.
Now the question is if the back pointer changes a lot of not. Because
normally this should not
be difficult to have one single entry point to set it up and remove it.
My experience with AST visitor based walking taught me that I like
bakc pointer.
We are searching for elements with a visitor, but the refactoring
itself happens independently.
We need the knowledge about the parent of each DocumentItem while doing
the refactoring (e.g. for removing). We can not do the refactoring
with a visitor, because we want to present the search result to the
user for selection. If we have to deal with this without back links, we
need to collect the parents in the search-visitor and keep this
information temporarely in the search result. This would not be nice as
it is not the responsibility of the search result to know the parent of
the found elements.
Daria & Norbert
17 May
17 May
8:49 p.m.
New subject: Owner of SW2WikiObjects
Hi Daria & Norbert,
does Java supports copying of an AWT window and then have two
independent windows on the screen afterwards? Does it support
transparent serialization? Am I able to load an AWT window from a
file and display on the screen with the same state when it was saved?
Am I able to have the same AWT window on two machines sharing the
same state and model over a TCP connection? Am I able ... I doubt so :-)
I guess it is no problem to implemented a parent link, however make
sure that copying works properly. As usual, for such a kind of patch,
I suggest that you do the modifications directly in SmallWiki2-Model
and then send the Monticello-Package to me. If there is a convincing
number of tests, I will merge it with the lastest code as soon as
possible.
Cheers,
Lukas
--
Lukas Renggli
http://www.lukas-renggli.ch
>> For
the refactoring of pages we need to know the (direct) parent
>> of each SW2WikiObject (especially SW2DocumentItem subclasses).
>> SW2WikiObject has the instance variable owner, but it is not
>> always used.
>> We thought it would may be of general interest to always have
>> this attribute. Would it be possible to get this feature?
>>
>
> In my opinion, back-links are generally a bad thing and therefor
> I try to avoid them whenever possible. Have a look at the i-var
> parent in SW2Structure and SW2Decoration and all the hassle
> around this. Back-links duplicate information and it makes
> several things, such as copying, more difficlut.
>
As far as we know, DocumentItem matches a composite pattern. Most
composite patterns do have parent links (e.g. Java AWT and there
seems no problem).
7188
days inactive
7188
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participants (2)
-
Lukas Renggli -
Norbert Kottmann