[Seaside] Error: Components not found
Colin Putney
cputney at wiresong.ca
Thu Oct 21 20:55:23 CEST 2004
Avi Bryant wrote:
> A component's callbacks are evaluated in the dynamic context of its
> ancestors in the UI tree. This lets its ancestors "control" those
> callbacks - they can prevent them from executing if the user has not
> been authenticated, for example, or they can catch validation errors
> that occur within them and record these for displaying to the user
> later, or they can set up thread-local variables that will be useful to
> them, and so on. To achieve this, the component tree is walked
> recursively during callback processing, and the callbacks for each
> component are executed as it is visited. The #children method controls
> this traversal - it's what's used to know which subcomponents to recurse
> into. If a component isn't listed in #children, it won't get visited,
> and so its callbacks will never get executed.
You know, this is enough of a FAQ that it might be worthwhile to have
the superclass implementation call #subclassResponsibility and have a
comment similar to the above paragraph.
It might be a little annoying for components that don't have children,
but at least it would be clear.
Colin
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