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

Dancer::Test + Devel::Cover + subroutine attributes == PAIN
by David Cantrell 29 Nov '12

29 Nov '12

We're using subroutine attributes on our route handlers for authentication. eg, things like ... get '/phonecall/:from/:to/:datetime/download_mp3' => sub :Auth( Government TabloidPress ) { ... }; and have a 'before' hook that checks that only logged in users who have the 'Government' or 'TabloidPress' role can listen in on other peoples' phone calls. This works nicely, both when we run the application and when we test it using Dancer::Test. However, we'd quite like to get some metrics of how good our tests are, and Devel::Cover is the tool for that. Trouble is, something is breaking, and the attributes are going missing somewhere. I've boiled it down to a *really* minimal app and tests, which are appended to this 'ere email. If I run the app, it works: $ ./app.pl & [1] 314 ... $ GET http://localhost:3000/plato I can Philosophise and if I run the tests without Devel::Cover, they work too: $ PERL5LIB=lib prove -rv ./t/test-devel-cover.t .. 1..4 ok 1 - GET /plato - status OK ok 2 - content looks good for /plato ok 3 - GET /leonardo - status OK ok 4 - content looks good for /leonardo ok All tests successful. but throw Devel::Cover into the mix too, and it all gone done buggerup: $ PERL5OPT=-MDevel::Cover PERL5LIB=lib prove -rv ./t/test-devel-cover.t .. 1..4 Use of uninitialized value in concatenation (.) or string at lib/TestApp.pm line 35, <DATA> line 998. ok 1 - GET /plato - status OK Use of uninitialized value in concatenation (.) or string at lib/TestApp.pm line 35, <DATA> line 998. not ok 2 - content looks good for /plato ... I can see (by inserting some print statements!) that the attributes are getting stored, but something is happening to prevent them from being pulled back out again. Has anyone else worked with Dancer and Devel::Cover and got any tips for me, or am I going to have to delve into the lump of pure concentrated EVIL that is the Devel::Cover source? $ cat app.pl #!/usr/bin/env perl use strict; use warnings; use lib 'lib'; use Dancer; use TestApp; dance; $ cat lib/TestApp.pm package TestApp; use strict; use warnings; use Dancer qw(:syntax); use Attribute::Handlers; my %attrs; sub Auth :ATTR(CODE) { my ($package, $symbol, $referent, $attr, $data) = @_; if(!ref($data)) { $data =~ s/^\s+|\s+$//g; $data = [split(/\s+/, $data)]; } $attrs{$attr}->{$referent} = $data; } sub get_attribs { my $class = shift; my $sub = shift; my $type = shift; return @{$attrs{$type}->{$sub} || []}; } hook 'before' => sub { my $handler = shift->code(); var('route_roles', __PACKAGE__->get_attribs($handler, 'Auth')); return; }; get '/plato' => sub :Auth(Philosophise) { "I can ".var('route_roles') }; get '/leonardo' => sub :Auth(Engineer) { "I can ".var('route_roles') }; 1; $ cat t/test-devel-cover.t use strict; use warnings; use TestApp; use Dancer::Test; use Test::More tests => 4; foreach my $tuple ( [ '/plato', 200, 'Philosophise' ], [ '/leonardo', 200, 'Engineer' ], ) { my ($url, $status, $lookfor) = @{$tuple}; response_status_is [GET => $url], $status, "GET $url - status OK"; response_content_like [GET => $url], qr/$lookfor/, "content looks good for $url"; } -- David Cantrell | Nth greatest programmer in the world NANOG makes me want to unplug everything and hide under the bed -- brian d foy

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Dancer advent calendar 2012 - help wanted!
by David Precious 26 Nov '12

26 Nov '12

Hi all, It's that time of year again - advent calendar time! I think it would be nice to continue the tradition and do an advent calendar again, and I'm happy to put in the work writing some articles and coordinating effort, so, let's do it! With that said, help would of course be greatly appreciated :) I have updated the README in the advent-calendar repo at: https://github.com/PerlDancer/advent-calendar I've added some article ideas there already; more ideas, and volunteers to write some of them, would be awesome. The advent calendars in previous years have been an interesting way to get extra attention for Dancer, and do pull in quite a few views. Analytics shows that they continue to receive views all year round, too. (To give an idea how many, from Jan 1st 2012 to present, 12,271 people visited the advent calendar site; 24,969 visits in total, with 43,510 pageviews, 47% being new visitors, with an average visit duration of 01:50, and average 1.74 pages per visit. That's some effective marketing, and well worth adding to, I think! :) ) Cheers Dave P -- David Precious ("bigpresh") <davidp(a)preshweb.co.uk> http://www.preshweb.co.uk/ www.preshweb.co.uk/twitter www.preshweb.co.uk/linkedin www.preshweb.co.uk/facebook www.preshweb.co.uk/cpan www.preshweb.co.uk/github

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Dancer::Plugin::Auth::Extensible - an authentication & access control framework for Dancer apps - RFC
by David Precious 25 Nov '12

25 Nov '12

Hi all, I've finally had time to hack further on the new Dancer authentication / access control plugin I've been working on, and it's at a state where I plan a beta CPAN release soon. The module is Dancer::Plugin::Auth::Extensible, and can be found on GitHub: https://github.com/bigpresh/Dancer-Plugin-Auth-Extensible I've written this as I tried to use D::P::Auth::RBAC, but I never really got on with it, and IMO it needed a lot of work - so I decided to write this from scratch. The plan is to make user authentication and access control dead simple, whilst also being extensible. I'd very much appreciate comments and suggestions from anyone who has time to look. Just to give an idea how it works - you configure the plugin via the app's config file (exactly what you put in depends on the authentication provider you're using), then denote which routes require authentication or specific roles using subroutine attributes - for instance: get '/secrets' => sub RequiresLogin { tell_secrets(); }; get '/really-secret' => sub RequiresRole(BestFriend) { tell_everything(); }; The first role could be accessed by anyone who is logged in; the second can only be accessed by people with the specified role. (If you only need basic authentication and not roles, you can ignore the role features; if you later need roles (e.g. you realise you need some users with higher privileges than others) it's trivial to start using them. The example app shipped with the module is a good place to look for a simple example: https://github.com/bigpresh/Dancer-Plugin-Auth-Extensible/tree/master/examp… The framework is designed to to be flexible enough to use various methods of authentication via the "provider" classes, and for new providers to be easy to write. All provider classes inherit from a base class which provides a constructor, ensures the provider implements the required methods, and provides a simple way to validate crypted passwords, so there is no reason that passwords should be stored in plain text, ever. So far, there is a "Config" provider which authenticates against usernames and passwords in the app's config, a "Database" provider which authenticates against a database (using the Database plugin), and a "Unix" provider which authenticates against system accounts on a *nix-type box. A DBIx provider is coming soon, and others (such as IMAP/LDAP) may well be provided too. As the framework supports multiple realms, it's possible to configure it to e.g. look in a database first, then try an IMAP server. A basic login page, login handling code etc is provided automatically, but can be overridden if desired. I'm about to put this in to use myself; I'm hoping it will be of use to other people, too. So, please do let me know what you think, whether it's of use to you, and whether there are any features that would make it more useful to you! I plan to tidy up the code a little and and improve the documentation before a proper release, but it's in a position where I'm fairly happy it works as it should, and already has a test suite of > 30 tests which pass happily. Cheers Dave P -- David Precious ("bigpresh") <davidp(a)preshweb.co.uk> http://www.preshweb.co.uk/ www.preshweb.co.uk/twitter www.preshweb.co.uk/linkedin www.preshweb.co.uk/facebook www.preshweb.co.uk/cpan www.preshweb.co.uk/github

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[Dancer2] Dancer::Template::Simple
by Damien Krotkine 01 Nov '12

01 Nov '12

Hi, So, now I'm puzzled :) I thought we wanted to get rid of Dancer::Template::Simple and use Template::Tiny. Why then do we still have Dancer::Template::Simple in Dancer2 ? Is it for backward compatibility ? does it need to be removed soon ? Thanks

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Template::Tiny forkage
by Damien Krotkine 01 Nov '12

01 Nov '12

Hi, As discussed previously, Dancer2 now embeds its own Dancer::Template::Implementation::ForkedTiny. I know the name is awful :) However, please let me know of any template issues you have with this new version. This new T::Tiny forked version open the path to more plugin compatibility, including FlashMessage and FlashNote. https://github.com/PerlDancer/Dancer2/commit/582447e3873df9db00ca4659b3df82… dams.

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