Django runserver needs restart on psql data changes

[Arnab Banerji]

Hi all - I am working on a Django app that interacts with a psql database via a set of models. 

(1) There is a backend job which keeps updating the database via the same models. 

(2) I am creating a table with a view using django_tables2 - and giving it a custom dictionary to render using data from the psql database (via my Django models). 

(3) I am using 'runserver' fpr testing out my code. 

The rendering happens perfectly, but the problem is - when the client user does a browser refresh, the new data does not get reloaded until I restart the runserver. Is there something I am doing wrong with respect to getting the data from the database and into my view?

Appreciate any help you might give me on this topic,

-AB

[Javier Guerra Giraldez]

On Wed, Apr 29, 2015 at 12:35 PM, Arnab Banerji <arn...@gmail.com> wrote:
> The rendering happens perfectly, but the problem is - when the client user
> does a browser refresh, the new data does not get reloaded until I restart
> the runserver. Is there something I am doing wrong with respect to getting
> the data from the database and into my view?

sounds like you're storing that data in a variable. you should either
read it from database on every request, or get some cache invalidation
techniques.

--
Javier

[Arnab Banerji]

Hi Javier - thanks for the response. Yes - I am storing the data in a dictionary - then having django_tables2 API render the dictionary as a table. How do I force a read of that variable for every browser refresh on the client side? 

Thanks for your time,

-AB

[Carl Meyer]

Hi Arnab,

On 04/29/2015 03:13 PM, Arnab Banerji wrote:
> Hi Javier - thanks for the response. Yes - I am storing the data in a
> dictionary - then having django_tables2 API render the dictionary as a
> table. How do I force a read of that variable for every browser refresh
> on the client side?

Using a variable is fine; the problem is that (I'm guessing) you are
creating that variable at the top level of the module. Such code is only
run once, when the module is first imported.

You need to make sure that all database queries are run only inside view
functions (or methods of view classes), never at the top-level of a module.

carl

[Arnab Banerji]

Hi Carl - that was *exactly* what I was doing - thanks a ton for finding that issue even without requiring the code. Now that I think about it, putting that definition in the global section makes absolutely no sense.

Appreciate your feedback,

-AB