Re: [Exist-open] Exist Backend process

[Efraim F. <efr...@gm...>]

Hi,

On 01/09/2012 01:40 AM, RAHUL AADITYA wrote:
> Is there anything like BackProcess in Exist-xquery? i.e., If i m 
> clicking on a button to search datas using xquery and after receiving 
> the datas, customer will be looking on the displayed datas.
>
> Meanwhile i want Exist to perform some back process. Let me explain, 
> while the customer is busy at looking datas i want to use xquery and 
> get ready the next records. So that when the customer click on the 
> next button the datas need to be displayed faster.
>
> Is this is possible? if there is any related article available to this 
> please direct me towards it. Need your assistance as early as possible.

There may be other ways to do it, but I can immediately think of 2:
(1) the util:eval-async() function to start evaluating the next xquery 
at the beginning or end of executing the previous one
(2) a job queue that runs through the scheduler module every few seconds 
and polls for the next request; and if any requests are enqueued, run 
them (I implemented something like this to use for background caching 
some processing: 
https://github.com/opensiddur/opensiddur/blob/master/code/apps/jobs/modules/jobs.xqm 
).

You'll presumably have to implement some way to block if the processing 
is incomplete by the time the user presses next.

-- 
---
Efraim Feinstein
Lead Developer
Open Siddur Project
http://opensiddur.net
http://wiki.jewishliturgy.org