[Seaside] nesting #call: in a single request? possible? ideas?

Julian Fitzell jfitzell at gmail.com
Wed Mar 2 08:55:04 UTC 2011


On Tue, Mar 1, 2011 at 11:14 PM, Michal <michal-list at auf.net> wrote:
>
>> right now I see that it kind of can't be done (raising a
>> WATaskNotDelegated), but I could be missing something
>
> If I understand your problem, it can actually be done, but because of
> some quirk the embedded task must be included in #children -- see my
> message about this a few weeks ago on this list. (There are actually
> some more quirks, that I am still investigating)

I don't think so, because he's talking about doing multiple calls in a
single request and a call immediately triggers rendering, preventing
you from doing any other callback code... but as I said, I'm certain I
understood the question.

> This is one thing that used to be more straightforward in earlier
> versions of seaside.

It was more straightforward in some ways, but the changes are largely
due to the move to partial continuations. As well as being
inefficient, the full continuations were not accurately mapping what
was going on and resulted in some really weird bugs like your
exceptions being handled in different contexts than the ones you set
up, responses being returned to old socket connections, and so on. The
tasks used to be kicked off in a different way, but that resulted in
them being executed during the render phase, which we explicitly say
should not make changes to state.

As I said, I suspect what you reported in your other email was a bug -
I don't think you should need to include called presented in #children
(though the distinction of why seems so confusing to explain, I almost
wonder whether we wouldn't be better to recommend it anyway...).

Julian


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