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Medium-Scale Dancer series updated
by Warren Young 29 Dec '15

29 Dec '15

I’ve just finished a touch-up pass on my series of articles on getting beyond the initial small-scale app design generated by “dancer -a app”. They were to be part of the 2015 advent calendar, but for now, here are the current links: Part 1, modules: https://goo.gl/SFn30N Part 2, routes: https://goo.gl/UfMqGo Part 3, views: https://goo.gl/DN8xYO Part 4, front end: https://goo.gl/wlyOFB Part 5, REST API: https://goo.gl/VbMI4P Part 6, reloader: https://goo.gl/6AiiIm (These are GitHub links, showing the current tip-of-master versions, shortened so they don’t break due to line wrapping.) The major change is that I’ve replaced the context object idea with direct Dancer DSL calls. I had poor justifications for this object, which I realized after watching Alexis Sukrieh’s 2015 conference video. That in turn allowed me to drop a level of function calls, which makes the recommended design considerably cleaner. I’ve also fixed up some UTF-8 problems, so you don’t get broken Latin-1 characters when viewing the articles in a web browser. (They look fine on a UTF-8 terminal. :) )

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Calling all plugin authors and plugin users
by Sawyer X 29 Dec '15

29 Dec '15

Hi everyone and merry $whatever_you_celebrate! Yesterday I finished the last patches to our new plugin system branch[1], supporting the old plugin syntax while working with the new one. There are two exceptions, mentioned in the original PR[2]: * You cannot call `use Dancer2` in the plugin. We currently do not detect this. We might be able to add this check. * You cannot import specific keywords from a plugin. We might be able to support it in the future, but it isn't supported at the moment. We do detect this and croak() if we see it happen, so you know what to do. Other than that, the old syntax seems to work. I want to ask all plugin authors to test their plugins. All users are also asked to report any issues. We would like to release a tentative trial version this weekend and, if all goes well, push this to production soon after. The plan is to then deprecate the old plugin syntax. We haven't decided yet what the timeline should be (a month, six months, two releases, six releases, etc.) but we will openly discuss this and are interested in all suggestions and comments. I have opened a ticket[3] to track all plugins we work with and the changes they might require (if they fall on one of the first two cases indicated above). We would appreciate any and all help! I will try and write a utility that automatically checks plugin code for the aforementioned problems. Please let us know if and how we can help you help us help you help all of us. :) Sawyer. [1] https://github.com/PerlDancer/Dancer2/tree/plugins-yanick [2] https://github.com/PerlDancer/Dancer2/pull/1010 [3] https://github.com/PerlDancer/Dancer2/issues/1078

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Videos 2015 + Conference 2016
by Stefan Hornburg (Racke) 17 Dec '15

17 Dec '15

The Perl Dancer Conference proudly presents the videos from the talks in Vienna: https://www.youtube.com/playlist?list=PLf1KDvMbyeCQq4mkMt8jDPzS9uPUX_mNo Thanks to our sponsors (https://www.perl.dance/sponsors) without their support this extensive coverage wouldn't be possible. Thanks to Amanda Crow at A. Crow Editing for the intricate editing work. The feedback from the speakers and other participants was really encouraging, so we are going to start planning for next year's event in January. Please feel free to make suggestions about venue, schedule and everything else which could be improved for 2016. Regards Racke -- Perl and Dancer Development Visit our Perl::Dancer conference 2015. More information on https://www.perl.dance.

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Dancer2 deployment
by Richard Reina 09 Dec '15

09 Dec '15

Happy Saturday All, For the past few months I've been playing around with dancer on a machine at home. I am wanting to now experiment with creating and perhaps deploying a simple web app on digitalocean. However, I am not clear why I need a web server such as Starman. Can I not just install Dancer2 and plackup like I do on my local machine? Thanks

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Dancer2::Plugin::Auth::Extensible problem - likely me
by John Stoffel 05 Dec '15

05 Dec '15

I'm trying to play with Authentication in Dancer2, and I can't get the dang example from Gabor at his blog (http://perlmaven.com/password-protecting-web-pages-in-dancer2) to run, it keeps giving me the following error: No Auth::Extensible realms configured with which to authenticate user at /home/stoffj/perl5/perlbrew/perls/perl-5.14.2/lib/site_perl/5.14.2/Dancer2/Plugin/Auth/Extensible.pm line 1160. HTTP::Server::PSGI: Accepting connections at http://0:5000/ And I'm going a little crazy. I'm using a perlbrew interpretter on CentOS 6.7, runnning perl 5.14.2, with all the latest modules installed. >From looking at the Extensible.pm file, it's warning from the on_plugin_import() sub where it's looking for Realms. I've got the following config.yml file setup: show_errors: 1 session: "YAML" logger: console log: core plugins: Auth::Extensible: realms: config: provider: Config users: - user: 'foo' pass: 'bar' name: 'George Foo' roles: - Marketing - user: 'bar' pass: 'foo' name: 'George Bar' roles: - Testing - Marketing - Management And my app.pl looks like this: #!perl # use strict; use Dancer2; use Dancer2::Plugin::Auth::Extensible; get '/' => sub { return 'This is a public page. Everyone can see it. Check out the <a href="/report">report</a>'; }; get '/report' => require_role Marketing => sub { return 'Only authenticated users should be able to see this page'; }; dance; And I'm invoking it like this: ~/tmp/Dancer2> ../../perl5/perlbrew/perls/perl-5.14.2/bin/plackup -R . app.pl Watching . ./lib app.pl for file updates. No Auth::Extensible realms configured with which to authenticate user at /home/stoffj/perl5/perlbrew/perls/perl-5.14.2/lib/site_perl/5.14.2/Dancer2/Plugin/Auth/Extensible.pm line 1160. HTTP::Server::PSGI: Accepting connections at http://0:5000/ So does anyone see what I'm going wrong here? Thanks, John

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Re: [dancer-users] single-threaded
by Rick Leir 24 Nov '15

24 Nov '15

On Tue, Nov 24, 2015 at 7:00 AM, <dancer-users-request(a)dancer.pm> wrote: > > This means that if you write your Dancer route handlers to be efficient, > so that they return within a few milliseconds at most, you can in effect > serve a great many clients, since most of them will be idle most of the > time. > > The single-threaded web server only breaks down when you start getting to > load levels where the server is handling at least one connection all the > time, so that allowing to to handle a second or third in parallel can > provide some benefit. > What if your route handler goes to disk for something (perhaps a DB access)? Your other Starman process(es) could start handling another connection in the meantime. What if your CPU has 2 or more cores (likely)? Again, the other process could get going. Maybe you have low traffic on an Intranet. But out on the Internet, you could have bots and spiders bothering your route handlers just when you have a real client to serve. Cheers -- Rick

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Re: [dancer-users] session cookies
by Rick Leir 19 Nov '15

19 Nov '15

On Thu, Nov 19, 2015 at 7:00 AM, <dancer-users-request(a)dancer.pm> wrote: > > This blog of mine might be helpful in understanding how it all works: > > http://blog.geekuni.com/2015/06/three-ways-to-implement-sessions.html > We should also be talking about JWT JSON Web Tokens because the Cookie scheme is broken. I use Crypt::JWT . These links explain it nicely: https://auth0.com/blog/2014/01/27/ten-things-you-should-know-about-tokens-a… http://jwt.io/ JWS https://tools.ietf.org/html/rfc7515 JWT https://tools.ietf.org/html/rfc7519 http://stackoverflow.com/questions/20504846/why-is-it-common-to-put-csrf-pr… Cheers -- Rick

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Question About Session Variables
by Richard Reina 19 Nov '15

19 Nov '15

Hello All, Hypothtetical question: When user 'A' logs in to my Dancer2 App, the app creates the session variable 'user_id' after authenticaltion and passes it to to other routes throughout the app. If at that point another user logs in, user B or even multiple users, is there any risk of the session 'user_id' getting overwritten by another user?

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No Advent Calendar this year
by Sawyer X 18 Nov '15

18 Nov '15

Hi everyone, I'm sorry to say, but we do not have enough time and volunteers to put out an Advent Calendar this year. I appreciate the comments made on the thread I started on it - and the ideas raised remain in the Calendar repo and I hope we will reach them eventually. Unfortunately, it will not be this year. My apologies and thanks again for the support and understanding. Sawyer.

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Re: [dancer-users] blocking
by Rick Leir 18 Nov '15

18 Nov '15

On Tue, Nov 17, 2015 at 7:00 AM, <dancer-users-request(a)dancer.pm> wrote: > > delayed { > my $TextToWrite = ReturnText(); > sleep(10); # Do something that takes a few seconds > content "$TextToWrite"; > done; > }; The sleep call will always cause blocking, even a sleep(0). Likewise a flush. In the sense that there is a context switch to some other thread or process. How are you testing whether it is blocking? Sorry, I do not know what you are trying to do. Linux will not schedule a cpu intensive task to the exclusion of I/O. You can affect its scheduling using nice: http://stackoverflow.com/questions/2012852/control-a-perl-scripts-cpu-utili… If you really want nonblocking then you can look at nice for io http://linux.die.net/man/1/ionice or spawn a C program with pthreads and freeze your screen! cheers -- Rick

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