[Seaside] Re: Menu component - communicating with root component
kleinsor at smallish.org
Mon Apr 21 10:54:06 UTC 2008
Boris Popov schrieb:
> Still, we've build what I consider to be a relatively large and complex
> application and I don't recall ever thinking that it was getting out of
> control. Certainly not to the point of introducing more elements just to
> glue announcers and subscribers together. Let's try a more complex
> example to see if perhaps I am missing something. Say you have a table
> containing rows containing cells and cells announce CellClicked when you
> click on them. If, for some reason, you were interested to know about
> that happening up in the table, how about something like,
the example works, because you have have homogenous components (table
related). If you insert a different kind of component not related to
tables somewhere in the hierarchy, it either has to deal with
"CellClicked" announcements (which is something it shouldnt have to know
about), or the parent (table component) has to subscribe to
grandchildren (row/cell components) directly, bypassing over the
non-table child component.
AFAIK there's no "childComponent
whenAnnouncingSomethingI'veNotSubscribedToDo: [ : ann | self announce:
ann copy ]" mechanism do pass unknown announcements.
In contrast, when handling errors with #on:do:, signals not matching the
specified classes automatically bubble up.
the kind of application I had in mind is highly configurable and
schema/content-driven, with only little hardcoded logic, so wiring
together components is tricky with regard to this problem. also, the
sibling problem had to be solved, so I've carried on with the
environment object approach. But it's definitely no silver bullet, so
the using direct subscriptions probably covers most cases.
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