[Seaside] Re: Re: Re: Re: Ajax callback question: how toupdatecomponenttreebefore #children gets called?

itsme213 itsme213 at hotmail.com
Fri Feb 8 20:13:41 UTC 2008

"Lukas Renggli" <renggli at gmail.com> wrote in message

> the owner of all callbacks in your tab panel
> is the SUCounter that just disappeared. And there is
> nobody that takes care of these callbacks. Bummer.

Ah. This could make some kinds of Ajax difficult.

> I guess
> this solution could be applied to this problem as well and would solve
> many sleepless nights.

That would be great! Callback problems are the most difficult part of 
Seaside for me to debug.

> Thanks for providing such a nice example to
> reproduce this problem.

My pleasure, its good to find some good side to my bad programming :-)

Below might be another pattern: an operation on (the domain model of) a 
parent component is actually presented on a child component (the parent 
configures the child).

House>>deleteRoom: aRoom
HouseComponent (model=house)
  RoomComponent 1 (model=r1)
    ['delete'->[house deleteRoom:r1.
                rend render: houseComponent]]
  RoomComponent 2 (model=r2)
    ['delete'->[house deleteRoom:r2.
                rend render: houseComponent]]

e.g. Desktop compound-document/component systems allow elements to negotiate 
with parents/children/root about where menus appear. It would be awesome if 
Seaside's architecture enabled similar composition flexibility. It would 
mean that...
  > Callbacks are normally processed in the context of the component that
  > defines them (the owner).

... the component that presents a callback need not be the one that 
"defined/owns" it. Not so much "homeless", more like "bind-and-relocate" 
(bind: r1 or r2, relocate: from house to r1, r2).

Perhaps seaside components have a special notion of "environment" that could 
be made explicit?

> This is usually not a problem, if you have a moderate number of children.

Good to know.

> Pay attention to use the right renderer. Even if it mostly works, I
> just noticed that there are some places where you use html within an
> AJAX callback.

Yikes! Even *I* should know better than to do that. A Lint smell?

As always, with many thanks.


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