Hi Anthony, thanks for the reply! I have been looking at the code and there is something I don't really understand (sorry for a noob question): when the functions get called, they are called using a pattern:
ret = ... ret and [f(fields,ret) for f in self._after_insert] return ret The question is - should the function I define return something? Is the result of the function call used somehow, somewhere? I suspect that using ret and [] is simply in order to invoke the functions, but then I don't understand why not use something like [f(fields,ret) for f in self._after_insert] without using the and operator. Best wishes, Omri On Wednesday, June 6, 2012 3:44:46 PM UTC+2, Anthony wrote: > > In trunk, there are now triggers for DAL tables: > > self._before_insert = [] > self._before_update = [lambda self,fs:self.delete_uploaded_files( > fs)] > self._before_delete = [lambda self:self.delete_uploaded_files()] > self._after_insert = [] > self._after_update = [] > self._after_delete = [] > > You could define a function that stores a timestamp in the cache and add > it to the three "_after_" triggers for the relevant tables. Then just check > the timestamp to see if it is more recent than the last request. To > determine the time of the last request, you could store a timestamp in the > session upon each request (so it will be specific to each user). > > Anthony > > On Wednesday, June 6, 2012 5:30:56 AM UTC-4, Omri Har-Shemesh wrote: >> >> Is it possible to watch a table for changes and define a callback >> whenever the table is changed? >> I am trying to implement a mechanism where the client is asking for data >> every 5 seconds from the server >> and the server should only return not a null value whenever the data has >> changed. The problem is that >> the data is quite complex and is inferred from several tables. Therefore, >> in order to save processing time, >> I want to calculate this data and return it only when I know it has >> changed. >> >> Thanks, >> Omri >> >
