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Dancer-Plugin-Auth-Tiny-0.002
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/ Dancer::Plugin::Auth::Tiny

NAME

Dancer::Plugin::Auth::Tiny - Require logged-in user for specified routes

VERSION

version 0.002

SYNOPSIS

use Dancer::Plugin::Auth::Tiny;

get '/private' => needs login => sub { ... };

get '/login' => sub {
  # put 'return_url' in a hidden form field
  template 'login' => { return_url => params->{return_url} };
};

post '/login' => sub {
  if ( _is_valid( params->{user}, params->{password} ) ) {
    session user => params->{user},
    return redirect params->{return_url} || '/';
  }
  else {
    template 'login' => { error => "invalid username or password" };
  }
};

sub _is_valid { ... } # this is up to you

DESCRIPTION

This Dancer plugin provides an extremely simple way of requiring that a user be logged in before allowing access to certain routes.

It is not "Tiny" in the usual CPAN sense, but it is "Tiny" with respect to Dancer authentication plugins. It provides very simple sugar to wrap route handlers with an authentication closure.

The plugin provides the needs keyword and a default login wrapper that you can use like this:

get '/private' => needs login => $coderef;

The code above is roughly equivalent to this:

get '/private' => sub {
  if ( session 'user' ) {
    goto $coderef;
  }
  else {
    return redirect uri_for( '/login',
      { return_url => uri_for( request->path, request->params ) } );
  }
};

It is up to you to provide the '/login' route, handle actual authentication, and set user session variable if login is successful.

If the original request contains a parameter in the passthrough list, it will be added to the login query. For example, http://example.com/private?user=dagolden will be redirected as http://example.com/login?user=dagolden&return_url=.... This facilitates pre-populating a login form.

CONFIGURATION

You may override any of these settings:

  • login_route: /login -- defines where a protected route is redirected

  • logged_in_key: user -- defines the session key that must be true to indicate a logged-in user

  • callback_key: return_url -- defines the parameter key with the original request URL that is passed to the login route

  • passthrough: - user -- a list of parameters that should be passed through to the login handler

EXTENDING

The class method extend may be used to add (or override) authentication criteria. For example, to add a check for the session 'is_admin' key:

Dancer::Plugin::Auth::Tiny->extend(
  admin => sub {
    my ($coderef) = @_;
    return sub {
      if ( session "is_admin" ) {
        goto $coderef;
      }
      else {
        redirect '/access_denied';
      }
    };
  }
);

get '/super_secret' => needs admin => sub { ... };

It takes key/value pairs where the value must be a closure generator that wraps arguments passed to needs.

You could pass additional arguments before the code reference like so:

# don't conflict with Dancer's any()
use Syntax::Keyword::Junction 'any' => { -as => 'any_of' };

Dancer::Plugin::Auth::Tiny->extend(
  any_role => sub {
    my $coderef = pop;
    my @requested_roles = @_;
    return sub {
      my @user_roles = @{ session("roles") || [] };
      if ( any_of(@requested_roles) eq any_of(@user_roles) {
        goto $coderef;
      }
      else {
        redirect '/access_denied';
      }
    };
  }
);

get '/parental' => needs any_role => qw/mom dad/ => sub { ... };

SEE ALSO

For more complex Dancer authentication, see:

For password authentication algorithms for your own '/login' handler, see:

ACKNOWLEDGMENTS

This simplified Auth module was inspired by Dancer::Plugin::Auth::Extensible by David Precious and discussions about its API by member of the Dancer Users mailing list.

SUPPORT

Bugs / Feature Requests

Please report any bugs or feature requests through the issue tracker at https://github.com/dagolden/dancer-plugin-auth-tiny/issues. You will be notified automatically of any progress on your issue.

Source Code

This is open source software. The code repository is available for public review and contribution under the terms of the license.

https://github.com/dagolden/dancer-plugin-auth-tiny

git clone git://github.com/dagolden/dancer-plugin-auth-tiny.git

AUTHOR

David Golden <dagolden@cpan.org>

COPYRIGHT AND LICENSE

This software is Copyright (c) 2012 by David Golden.

This is free software, licensed under:

The Apache License, Version 2.0, January 2004