[Dancer-users] Dancer::Session::SQLite

[P Kishor]

2010/8/24  <igor.bujna at post.cz>:
> Hello,
> can you try Dancer-Plugin-Database?? http://search.cpan.org/~bigpresh/Dancer-Plugin-Database-0.06/lib/Dancer/Plugin/Database.pm
> It's very simple method to connect DBI and use in Dancer.


Quoting from my earlier email ---

1. Getting db settings. Initially, I thought I could use
Dancer::Plugin::Database, so the same method could be used in the main
Dancer application as well as in my session plugin. However, I have
the following problems with D::P::Database -- (1) it doesn't really
work in D::Session::SQLite. I get the error that database method is
not declared (or something like that); and (2) it changes the regular,
more familiar DBI methods. In fact, I am not even sure how I would do
more DBI-ish things with it, such as transactions, etc. So, this is a
different issue, but for now, I am tabling Dancer::Plugin::Database.

>
>> ------------ Původní zpráva ------------
>> Od: P Kishor <punk.kish at gmail.com>
>> Předmět: Re: [Dancer-users] Dancer::Session::SQLite
>> Datum: 24.8.2010 17:52:17
>> ----------------------------------------
>> Thanks Alexis, for your advice. However...
>>
>>
>>
>> On Tue, Aug 24, 2010 at 1:33 AM, Alexis Sukrieh <sukria at sukria.net> wrote:
>> > On 24/08/2010 08:14, P Kishor wrote:
>> >>
>> >> Using Dancer::Session::YAML and Dancer::Session::Storable as
>> >> templates, I created a Dancer::Session::SQLite module. I put it in
>> >> /usr/local/lib/perl5/site_perl/5.12.1/Dancer/Session/SQLite.pm and set
>> >> session =>  'SQLite'. Yet, I get an error saying 'Error while loading
>> >> /Users/punkish/Sites/lca/app.psgi: unknown session engine 'SQLite',
>> >> perhaps you need to install Dancer::Session::SQLite? at
>> >> /usr/local/lib/perl5/site_perl/5.12.1/Dancer/Engine.pm'
>> >
>> > When Dancer parses your config file, it uses Dancer::ModuleLoader to load
>> > the session engine you chose. Hence it does internally a `use
>> > Dancer::Session::SQLite'.
>> >
>> > The error message you report tends to show that Dancer::Session::SQLite is
>> > not in @INC (or the use fails for another reason).
>> >
>> > First, I'd suggest to do the following to test your module without
>> > installing it:
>> >
>> >  YourApp/
>> >    ...
>> >    lib/
>> >      YourApp.pm
>> >      YourApp/
>> >      Dancer/
>> >        Session/
>> >          SQLite.pm
>> >
>> > Then try to do the following:
>> >
>> > $ perl -Ilib -MDancer::Session::SQLite -e 'print 1, "\n"'
>> >
>> > Maybe you'll see here the source of the error.
>> >
>>
>>
>> So, I debugged my module, and got the session working. Dancer creates
>> a session properly, and retrieves session values properly. There are
>> two issues that are blocking me from converting this into a
>> distributable module. Perhaps someone can help me with them --
>>
>> 1. Getting db settings. Initially, I thought I could use
>> Dancer::Plugin::Database, so the same method could be used in the main
>> Dancer application as well as in my session plugin. However, I have
>> the following problems with D::P::Database -- (1) it doesn't really
>> work in D::Session::SQLite. I get the error that database method is
>> not declared (or something like that); and (2) it changes the regular,
>> more familiar DBI methods. In fact, I am not even sure how I would do
>> more DBI-ish things with it, such as transactions, etc. So, this is a
>> different issue, but for now, I am tabling Dancer::Plugin::Database.
>>
>> 2. This is more of a show-stopper. I am getting a lock on my database
>> everytime a new session is inserted. Essentially, since I am running
>> my application via Plack::Handler::Apache2, the entire application is
>> being loaded in the web server's memory. It is creating a lock on the
>> db, and not letting go. If I restart the web server, the lock is
>> released, only to be created again when the session is updated.
>>
>> So, I am trying to figure out where to disconnect the db manually, but
>> I don't really understand the sequence of actions that Dancer::Session
>> takes. I have the following methods in my module
>>
>> package Dancer::Session::SQLite;
>> use DBI;
>> my $dbh = setting('dbh');
>>
>> init()
>> create()
>> session_db()
>> destroy()
>> flush()
>>
>> How and where should I call the $dbh->disconnect method?
>>
>>
>> > When you're happy with it, I suggest you create a real CPAN distribution
>> > (with Module::Starter). I'm sure other Dancer users could find
>> > Dancer::Session::SQLite interesting.
>> >
>> > Good luck.
>> >
>> > --
>> > Alexis



-- 
Puneet Kishor http://www.punkish.org
Carbon Model http://carbonmodel.org
Charter Member, Open Source Geospatial Foundation http://www.osgeo.org
Science Commons Fellow, http://sciencecommons.org/about/whoweare/kishor
Nelson Institute, UW-Madison http://www.nelson.wisc.edu
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