Re: [Exist-development] Execution Pipeline, async xquery execution...

[Adam R. <ad...@ex...>]

On 4 February 2010 10:27, Thomas White <tho...@gm...> wrote:
> On 3 February 2010 21:21, Andrzej Jan Taramina <an...@ch...> wrote:
>>
>> Thomas:
>>
>> > That will work, but it seams a little bit messy. The function has to be
>> > prepared specifically to know how to chain with re-scheduling call to
>> > itself at the end of the function.
>>
>> True, but that is a very simple thing to do, and the XQuery would be crafted to be run using the scheduler only (though
>> there are fancy ways to craft an XQuery that can run with a REST invocation and as a scheduled task).
>
> I this is an application very specific approach. I would use it only
> if there is no other way.
>
>> > On other hand if we have schedule-xquery-periodic-job extended to pay
>> > attentions to the returned value, then any function that returns boolean
>> > can be called repeatedly until the data is consumed.
>>
>> I'm gonna vote -1 on that.  It's outside of the scope of what a periodic scheduled job should do and is really
>> application specific.
>
> I think the opposite way - this is generic functionality. It is an
> equivalent of BREAK in FOR loop.
> I can't think about more generic then a break functionality.
>
> One more thing. When we have an asynchronous function it is very
> common to have a callback function that is called at completion of the
> main function. If we have an option to pass a callback function when
> we schedule an XQuery function, this will allow us to do post
> processing on the results.

You can already pass functions in XQuery through the function() and
call() functions. I agree with Andrzej though. Everything that you
need is already present.


> Thomas
>



-- 
Adam Retter

eXist Developer
{ United Kingdom }
ad...@ex...
irc://irc.freenode.net/existdb