Hello again Massimo, and thanks for the feedback.
I've been troubleshooting this all day long and i've tracked this down
to a view that i have that serves 2 images and two tables with
information from those two images.
That view is something like (the syntax is not this, just for
illustration purposes):
<div>
<div id="1">
<img src=URL(.....,f="generate_image",param=1) />
{{python code for the table using information on the
session...}}
</div>
<div id="2">
<img src=URL(.....,f="generate_image",param=2) />
{{python code for the second table using information on the
session...}}
</div>
</div>
All the tables are ok, but only the first image appears. If i go call
the URL of the second image directly on the browser url textarea, or
using firebug, the second image appears ok. The only difference
between both images is a parameter that calls inside the default.py
the function generate_image, but one parameter generates one kind of
image, the other parameter other kind of image. The images use
information from the session.
So what i found so far is:
- both images called separately work fine
- one after the other gives problems with session things
- both images are called one after the other, but it seems that at the
second time, the session object isn't defined at the time of function
call, and if i do a kind of "if (session.something is not None)" and
give something like a alert image, web2py creates a new session file
and leaves the first session file in the "session" folder..
It seems, that the second time the method "generate_image" is called,
the session is still not ready. If i don't return nothing, web2py
works fine. If i do a 'if' inside "generate_image" to return an alert,
web2py creates a new session and leaves the other in the folder.
Is there any way of "enforcing" the session object to be ready when a
function in default.py is called? Even if that slows down the response
from the server..
I'll keep on exploring, thanks,
João Ventura
On 6 Jun, 14:57, mdipierro <mdipie...@cs.depaul.edu> wrote:
> On Jun 6, 4:45 am, João Ventura <joaojonesvent...@gmail.com> wrote:
>
> > Hello mdipierro,
>
> > i only store basic python datatypes (dictionaries, floats, strings).
> > The most complex variables that i store are dictionaries inside other
> > dictionaries, with a max depth of 2 (i.e., a first dictionary with
> > secondary dictionaries inside it).
> > It is a bit strange for, while using the same client browser on the
> > same app instance (i.e., without reloading), after a while web2py
> > ignores the first session file and creates a second one. In other
> > words, in what situations is web2py designed to do this behavior?
>
> No. web2py reuses the same sessions for the same client over and over,
> unless it fails to retrieve a session.
> Try print request.cookies. It may help figure it out.
>
> > Also, are there any kind of methods for clearing the session files?
>
> You can have the app itself clear them or you can use a cron script
> like admin/cron/expire_sessions.py
>
> > Because with this kind of behavior, one gets the session folder filled
> > up very fast.. Is there any possibilty of session timeout and file
> > deletion?
>
> move admin/cron/expire_sessions.py into your app cron
>
> > Ah, this has already happened before, and the only common thing that
> > i've detected so far is that i use tab navigation with jquery's ajax
> > function to load content to a div. Any hints?
>
> I do not understand. Sorry.
>
> > Thanks,
> > João Ventura
>
> > PS: I'll try to debug my application down to the web2py source code to
> > see if something triggers my thought. Any ideia where to start
> > searching?
> > By the way, web2py is a great framework, i've started with Django,
> > couldn't do almost no production there, switch to web2py, and
> > production increased a lot... Just this annoying session behavior, but
> > hope it's a small bug..
>
> > On 6 Jun, 06:36, mdipierro <mdipie...@cs.depaul.edu> wrote:
>
> > > The only thing that comes to mind is if you try store an object in the
> > > session. The object may be an instance of class that you define and
> > > therefore web2py succeeds in storing the session but fails to retrieve
> > > it because the class is not yet defined (or imported) at the time when
> > > the session is retrieved (before your user code it executed).
>
> > > You can only store primitive types in session, not objects.
>
> > > On Jun 5, 9:04 pm, João Ventura <joaojonesvent...@gmail.com> wrote:
>
> > > > Hello everyone,
>
> > > > i've searched a lot but couldn't find any answer to the following: I'm
> > > > developing a web application, and i rely heavily on sessions, storing
> > > > all the user data on a session while the user uses a jquery tab
> > > > interface. The problem is that sometimes web2py loses the session
> > > > object, and it is almost in the same manner. I've checked my code many
> > > > times and i don't mess with the session object.
>
> > > > But as web2py does manage sessions automatically, i see that the first
> > > > time i use the app, web2py creates a session file in the session
> > > > folder. And when the contents of the first session disappears, when i
> > > > check the "sessions" folder, the previous session file is there with
> > > > all its contents, but now there's a new (empty) session file.
>
> > > > I can't give a simple example how to replicate the error, but i think
> > > > web2py shouldn't lose the first session, because:
> > > > - I haven't explicitely called anything like "session.forget()" that
> > > > could influence.
> > > > - I haven't opened any other browser instance, tab or any other
> > > > browser at all.
>
> > > > Anybody knows anything about this?
>
> > > > Thanks,
> > > > João Ventura
