well if you allow this then it nullifies what i tried to achieve. the
developers, even core ones, will start doing what i said, making onattach
final and providing an onattach2 because in some instances you have things
that are not meant to be overridible. so we will be back to square one.
-igor
On 1/4/07, Johan Compagner <[EMAIL PROTECTED]> wrote:
there is one problem of not being able to override some implementation in
an
onAttach
and that is that the component builder (maybe even wicket core) doesn't
put
that in
an overridable method so that i can nullify it or make my own impl.
Then i can never just override it with my own. And that could be a problem
if you are not in full control.
That can be very frustrating. Thats why i think adding an extra method
that
does set the flag
and by passes everything would be a good alternative. Because then you
really choose for it
you know what you are doing.
johan
On 1/4/07, Igor Vaynberg <[EMAIL PROTECTED]> wrote:
>
> well the problem is this
>
> lets say onattach() comes with no strings attached
>
> then you have Component->MyComponent
>
> MyComponent overrides onattach and puts something very important into
it,
> what to do now?
>
> there are two choices: make onattach() final, and provide a break out
> method
> called onAttach2() or something like that
>
> or leave it onattach() if you know the contract is always to call
super()
>
> now comes Component->MyComponent->MySecondComponent
>
> MySecondComponent also has something very important in onattach(), but
it
> cannot override onattach, so it overrides onattach2() adds its logic and
> provides another break out method onattach3()
>
> this gets very ugly very fast
>
> so what should components do? things that are meant to be overridden
> should
> be factored out into a protected method and called from onattach()
>
> i think the alternative of not forcing the call to super() is too ugly,
> that
> is why we had all those damned internalonattach/internalattach/blah
blah,
> but those were only places for _us_ the framework devels to have a place
> to
> put code we were sure would be executed in attach/detach.
>
> -igor
>
>
>
>
>
>
> On 1/4/07, Jan Vermeulen <[EMAIL PROTECTED]> wrote:
> >
> >
> > I agree with that. We indeed could invent ourselfs a method that we
call
> > from
> > within onAttach() to solve outr problem, but what if I'm not happy
with
> > what
> > someone else (possibly in some framework implementation) added to the
> > onAttach().
> >
> > If I commented the problem in the first place, it's because I like to
> > think
> > of these 'on...' methods as methods without any specific contract,
that
> > the
> > framework user can freely overwrite. It's more kind of a suggestion.
> >
> > Jan.
> >
> >
> > Johan Compagner wrote:
> > >
> > > but this could be a problem if somebody really wants to override
> > behavior
> > > of
> > > a component
> > > that is not in its own control. So maybe we should have a special
> final
> > > protected method that just sets the flag?
> > > That can also be called from the onAttach() instead of calling
super?
> > >
> > > johan
> > >
> > >
> > > On 1/3/07, Igor Vaynberg <[EMAIL PROTECTED]> wrote:
> > >>
> > >> well, unfortunately it is now a requirement due to various reasons.
> > >>
> > >> what you should do is factor out whatever behavior out of
onattach()
> > into
> > >> a
> > >> separate method, and then override that method in the subclass,
that
> > way
> > >> you
> > >> dont need to override onattach() in the subclass, and even if you
do
> > you
> > >> can
> > >> still call super.
> > >>
> > >> -igor
> > >>
> > >>
> > >> On 1/3/07, Jan Vermeulen <[EMAIL PROTECTED]> wrote:
> > >> >
> > >> >
> > >> > The problem is I don't want to call super.onAttach(), because the
> > code
> > >> of
> > >> > my
> > >> > onAttach() overwrites the behavior of the code in super.onAttach
().
> > >> > But if I don't call super.onAttach(), the flag FLAG_ATTACHING
never
> > >> gets
> > >> > reset, and Wicket throws an exception.
> > >> >
> > >> > Jan.
> > >> >
> > >> >
> > >> > igor.vaynberg wrote:
> > >> > >
> > >> > > what exactly is the problem?
> > >> > >
> > >> > > can you not do
> > >> > >
> > >> > > onattach() {
> > >> > > super.onattach();
> > >> > > togglevisibilityofchildren();
> > >> > > }
> > >> > >
> > >> > > and no you cannot use attachchildren(), it is package-private
> > >> > >
> > >> > > -igor
> > >> > >
> > >> > >
> > >> > > On 1/3/07, Jan Vermeulen <[EMAIL PROTECTED]> wrote:
> > >> > >>
> > >> > >>
> > >> > >> The last change in TRUNK related to onAttach(), with the
> > >> introduction
> > >> > of
> > >> > >> a
> > >> > >> (private) flag FLAG_ATTACHING that is reset in the onAttach()
of
> > >> > >> Component,
> > >> > >> is causing us problems. We have inherited components that
> override
> > >> the
> > >> > >> logic
> > >> > >> of the onAttach() of their superclass, typically
> > enabling/disabling
> > >> or
> > >> > >> hiding of child components in function of some dynamically
> > >> changeable
> > >> > >> state.
> > >> > >> With the introduction of the flag, we are bound to call the
> > >> > >> implementation
> > >> > >> of the superclass, in order to reset the flag correctly.
> > >> > >>
> > >> > >> Are we using onAttach() in a wrong way ? I understood it is a
> > >> callback
> > >> > >> method that allows component implementors to do their thing,
> > without
> > >> > >> having
> > >> > >> to worry about the internal attach logic. Or should we use
> > >> > >> attachChildren()
> > >> > >> for that ?
> > >> > >>
> > >> > >> Jan.
> > >> > >> --
> > >> > >> View this message in context:
> > >> > >>
> > >> >
> > >>
> >
>
http://www.nabble.com/onAttach%28%29-and-FLAG_ATTACHING-tf2913350.html#a8140407
> > >> > >> Sent from the Wicket - Dev mailing list archive at Nabble.com.
> > >> > >>
> > >> > >>
> > >> > >
> > >> > >
> > >> >
> > >> > --
> > >> > View this message in context:
> > >> >
> > >>
> >
>
http://www.nabble.com/onAttach%28%29-and-FLAG_ATTACHING-tf2913350.html#a8145567
> > >> > Sent from the Wicket - Dev mailing list archive at Nabble.com.
> > >> >
> > >> >
> > >>
> > >>
> > >
> > >
> >
> > --
> > View this message in context:
> >
>
http://www.nabble.com/onAttach%28%29-and-FLAG_ATTACHING-tf2913350.html#a8158789
> > Sent from the Wicket - Dev mailing list archive at Nabble.com.
> >
> >
>
>
