September 2012 - dancer-users - lists.preshweb.co.uk

dancer2's prototype is there, feedback needed
by sukria 05 Oct '12

05 Oct '12

Hi there, I am very glad and proud to announce here that I've came up with a prototype of dancer2 that pleases me enough to be advertised. -*- https://github.com/sukria/dancer2 -*- dancer2 is a complete rewrite of Dancer aiming at providing the same awesomeness with the following major changes: - no more globals in the core - 100% object-oriented backend (based on Moo) - better scoping for sub-applications - better design (no more encapsulation violations, Law of Demeter, ...) The prototype I've pushed to GitHub currently covers ~80% of the DSL of Dancer. It's able to run simple applications (it can run the PerlDancer.org website for instance). Of course, with your real-life applications, it will break in many places in this current shape, and this is where you can help. I'd like to have as many reports as possible regarding upgrades tests. You can test very easily your app with dancer2: $ git clone http://github.com/sukria/dancer2.git $ cd YOUR_APP $ perl -I../dancer2/lib bin/app.pl Also, important to know: most of the plugins may not be working well. Thanks a lot ;)

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Managing "sessions" for each open browser window
by Assaf Gordon 01 Oct '12

01 Oct '12

Hello, Another implementation question for my planned web-site: I want to maintain a "session" (i.e. collection of server-side variables) for each open browser window (not browser "session" in the technical sense). Use-case: 1. a user open a new browser window/tab, goes to my web-site. 2. user changes settings, does some stuff, information is stored for this "session" of open window. 3. same user, same browser, opens a new window/tab, goes (again) to my web-site - now gets a new "empty" session. 4. user changes settings, does some stuff, information is stored for this "session" of open window. 5. the two browser windows (from step 2,4) can be viewed side-by-side, each maintaining independent set of session information. Implementation-wise, I've seen similar web-sites assign a new CGI variable when a user visits the "root" (=landing) page, and propagate that variable in every generated link or HTML form. e.g.: 1. user visits http://myserver.com 2. user redirected to http://myserver.com/?session_id=5 3. from now on, every URL (generated by Dancer's templates) will carry the session ID. 4. if the user opens a new (empty) tab and visists "http://myserver.com" again, he will get "session_id=6" for that window. This seems reasonably easy to implement, but how do I connect the CGI session variable to some sort of Dancer's "session" keyword? I'm thinking of some "before" hook mechanism, but not sure how to go about it... Any suggestions are welcomed, -gordon P.S, I'm aware that a mischievous user could copy&paste the URL to another window, and have two open windows changing the same "session" - I'm not worried by this scenario (as users will be explained that such a thing will simply interfere with their work).

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New plugin Dancer-Plugin-FakeCGI
by igor.bujna＠post.cz 28 Sep '12

28 Sep '12

Hi everybody, let mi introduce my new plugin http://search.cpan.org/~koceasy/Dancer-Plugin -FakeCGI-0.21/. This plugin can easily run CGI methods or Perl CGI files under Dancer such as this simple example: # Run specified method in given package any '/test_1' => sub { fake_cgi_method("test_CGI", "test"); fake_cgi_as_string; }; <br># Run specified Perl file any '/test_3' => sub { fake_cgi_file("test_CGI_file.pl"); fake_cgi_as_string; };<br><br> This example is append in this plugin in directory examples. I wrote this plugin to easily move CGI script to use in Dancer. The idea is similar as running CGI under mod_perl. Than every package is after first run cached in memory or can be cached with method fake_cgi_compile. In next version i want to add emulation CGI function header() and cookie(). If someone know how can be easily implemented, than send me email. In future i would like to extend IO::Capture(such as not save some captured text.... ) Bye Igor

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Capturing STDOUT of an external program in a Route handler
by Gurunandan Bhat 26 Sep '12

26 Sep '12

Hi, I need to run an external command from within a route handler and read both STDOUT and the return value. I am currently using Capture::Tiny<https://metacpan.org/module/Capture::Tiny>to do this. my ($stdout, $stderr, $retval) = capture { # my code here ... }; I find however that while STDERR is captured correctly, STDOUT goes to the screen log (I am running in development mode, but production mode does not change anything). Is there some way to capture STDOUT rather than have it redirected to my log? Thank you.

1 0

Modular approach without anonymous subrefs
by gvim 25 Sep '12

25 Sep '12

I'm converting a CGI::Application web app to Dancer and have always used a modular approach so am I missing something if I prefer to do it this way: package MyApp; use Dancer qw(:syntax); use Login; use Logout; use Register; post '/login' => \&Login::run; post '/logout' => \&Logout::run; get '/register' => \&Register::run; 1; package Register; use Dancer qw(:syntax); sub run { ..... } 1; package Login; use Dancer qw(:syntax); sub run { ..... } 1; ? gvim

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Yanick Champoux joins Dancer core team
by sawyer x 25 Sep '12

25 Sep '12

I'm pleased and excited to announce that Yanick Champoux has joined the Dancer core team. We've all been lucky, both in the Perl community and the Dancer community, to enjoy the fruits of Yanick's labor, whether its in his numerous contributions to Perl modules (and Perl core) but also for his humorous and insightful blog posts. And yes, he is also that charming in person! Yanick is in charge of some big changes in Dancer (such as the megasplat feature) and we're honored to have Yanick on the team and know it will help propel Dancer - and mainly Dancer 2 - forward. Welcome! P.S.: Muhahahahahaha! :)

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Session ID in logger_format
by Stefan Hornburg (Racke) 24 Sep '12

24 Sep '12

Hello, fellow dancers! Would it be possible (at least in Dancer 2) to add the session id to the logger_format options? That is really helpful if you try to trace a problem / crash in your application. Regards Racke -- LinuXia Systems => http://www.linuxia.de/ Expert Interchange Consulting and System Administration ICDEVGROUP => http://www.icdevgroup.org/ Interchange Development Team

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running dancer under apache (as cgi or fastcgi)
by Nick Knutov 21 Sep '12

21 Sep '12

~/domains/test-dancer-app/www$ cat .htaccess Options +ExecCGI DirectoryIndex index.htm /dispatch.cgi RewriteEngine on RewriteCond %{REQUEST_FILENAME} !-f RewriteCond %{REQUEST_FILENAME} !-d RewriteCond %{REQUEST_FILENAME} !\.(swf)|(jpg)|(png)|(gif)$ RewriteRule ^(.+)$ /dispatch.fcgi$1 [L] ~/domains/test-dancer-app/www is alias for `.../public` # in hook `before` if ( !session('uid') && request->path_info !~ m{^/login} ) { return redirect '/login/'; } This gets redirect to `/dispatch.fcgi/login/` instead of /login/. When manually getting /login/ it gets internal server error with this text in log: "Request exceeded the limit of 10 internal redirects due to probable configuration error. Use 'LimitInternalRecursion' to increase the limit if necessary. Use 'LogLevel debug' to get a backtrace." Additionally, it seems `params` is always empty when url is `/dispatch.fcgi/...` The same app works perfect when run under Starman + nginx. But we are still trying to make good shared hosting for dancer, so the question is how to run this under Apache + mod_cgi/mod_fastcgi. -- Best Regards, Nick Knutov http://knutov.com ICQ: 272873706 Voice: +7-904-84-23-130

1 0

Web-front end for long-running processes
by Assaf Gordon 21 Sep '12

21 Sep '12

Hello, I'm planning a web site (w/ Dancer, of course :) ) that will execute shell scripts (to compute some results) and eventually return the results to the user. The web-side is simple enough, but the shell scripts might take anywhere between 10 seconds to 10 minutes to execute. Is there a recommended way to manage external jobs for this type of scenario ? One extreme is to use SGE/PBS and build a whole database-backed-up queuing system. The other is perhaps to execute the shell scripts (serialized, one after the other) and just send the results to the users by email. But if anyone has experience with something similar, any advice will be appreciated. (This is supposed to be a short-term project, just a front-end to some unix scripts - so I prefer to keep it simple, not build a full-fledged infrastructure from scratch). Thanks, -gordon

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Starman vs Plack::Handler::Apache2 my results
by David C gurugeek 19 Sep '12

19 Sep '12

Hello again, I am running this page http://dancer.1.ai using plackup -E deployment -s Starman --workers=10 -p 5001 -a ./bin/app.pl > and this page http://elephant.1.ai/perl using Plack::Handler::Apache2 in my tests Plack::Handler::Apache2 seems to be faster. Shouldn't it be the other way around ? I did try both with curl + safari and chrome benchmarks and even http://whichloadsfaster.com :) Thanks for your comments Regards David

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