On 2018-08-02 14:19, Jon Levy wrote: > When a function field is accessed multiple times without there being any > database operations, it will be calculated the first time, cached, and > subsequently recalled out of cache. > https://github.com/tryton/trytond/blob/1af9530e187d766598afd55bb6399ab0a5e8689b/trytond/model/modelstorage.py#L1232 > > The only way to prevent this that I can find (without messing with internals) > is to do a database operation (and thus increment the transaction counter), > signaling to the numerous caches that they should clear. > https://github.com/tryton/trytond/blob/1af9530e187d766598afd55bb6399ab0a5e8689b/trytond/cache.py#L219 > > Of course, explicitly changing the transaction counter would also accomplish > the aim. Does anyone know if this is acceptable? > > I understand that I should probably not even be talking about such things. > Why would the function field have changed without a database operation? I am > in a strange case where I have a function field that is used to generate a > report, but new legal guidance has been issued that creates two > interpretations of how that function field might be calculated. I have a > wizard that runs a series of reports, and the idea is to now have two > versions of the report: one for each method of calculating the function field > (based on a context flag). I understand that this is not great, and that > idiomatically the better thing to do would be to either convert the function > field into a regular python method, or use two different function fields. I > am just not investing the time to do that yet--in part because I think there > is a good possibility of new legal guidance coming out fairly soon. > > Any advice on how to not use the cache? (Btw, the avenue of doing a trivial > database operation to increment the counter also runs into problems because > reports are run in readonly transactions.)
As you said that your computation depend on the context, you should instantiate the record with each context. This way the computation will be redone. -- Cédric Krier - B2CK SPRL Email/Jabber: cedric.kr...@b2ck.com Tel: +32 472 54 46 59 Website: http://www.b2ck.com/ -- You received this message because you are subscribed to the Google Groups "tryton" group. To view this discussion on the web visit https://groups.google.com/d/msgid/tryton/20180802222141.kov3epa4ozsr5svm%40kei.
