Re: [Webware-discuss] class variables not persistent across requests ?

[deelan <de...@in...>]

Olivier Migeon wrote:

> To the best of my knowledge (correct me if I'm wrong), you can't rely on 
> instances variables to store persistent-accross-requests variables : the 
> instance may or may be not reused, may or not be cached.
true.

> 
> I though that storing the result of my query in a class variable would 
> solve the problem, but it doesn't.
> My code looks like this:
(...)

> So, my questions are :
> 
> 1) why doesn't it work ? It's not a caching issue because my 
> CacheServletClasses is set to 0 in my Application.config file.
i may be wrong but this setting means that at *every* page
request your MyPage class will be recreated from scratch.

> 
> 2) what is the best way to make persistent variables accross requests 
> and sessions ?

i use to compile-once cheetah templates and store them in
a dictionary stored in SitePage class var, like you do your
code. see below:

class SitePage(Page):

     # master page template
     HTML = 'site.html'

     # ... other code ...

     _cache = {} # master page template objects

     def writeHTML(self):

         if self.HTML in SitePage._cache:
             t = SitePage._cache[self.HTML]
         else:
             app = self.application()
             path = app.serverSidePath('www/t/%s' % self.HTML)

             # if file changes reload app
             modloader.watchFile(path)
             t = Template(file=path, filter=Latin1Encoder)

             SitePage._cache[self.HTML] = t

         # access to self with $s in template
         t.s = self
         self.write(str(t))


but CacheServletClasses must be set to 1 if I want that webware
caches servlet classes, hence page templates.


cheers,
deelan.