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NAME

       Dancer - lightweight yet powerful web application framework

SYNOPSIS

           #!/usr/bin/perl
           use Dancer;

           get '/hello/:name' => sub {
               return "Why, hello there " . param('name');
           };

           dance;

       The above is a basic but functional web app created with Dancer.  If you want to see more
       examples and get up and running quickly, check out the Dancer::Introduction and the
       Dancer::Cookbook.  For examples on deploying your Dancer applications, see
       Dancer::Deployment.

DESCRIPTION

       Dancer is a web application framework designed to be as effortless as possible for the
       developer, taking care of the boring bits as easily as possible, yet staying out of your
       way and letting you get on with writing your code.

       Dancer aims to provide the simplest way for writing web applications, and offers the
       flexibility to scale between a very simple lightweight web service consisting of a few
       lines of code in a single file, all the way up to a more complex fully-fledged web
       application with session support, templates for views and layouts, etc.

       If you don't want to write CGI scripts by hand, and find Catalyst too big or cumbersome
       for your project, Dancer is what you need.

       Dancer has few pre-requisites, so your Dancer webapps will be easy to deploy.

       Dancer apps can be used with a an embedded web server (great for easy testing), and can
       run under PSGI/Plack for easy deployment in a variety of webserver environments.

MORE DOCUMENTATION

       This documentation describes all the exported symbols of Dancer. If you want a quick start
       guide to discover the framework, you should look at Dancer::Introduction, or
       Dancer::Tutorial to learn by example.

       If you want to have specific examples of code for real-life problems, see the
       Dancer::Cookbook.

       If you want to see configuration examples of different deployment solutions involving
       Dancer and Plack, see Dancer::Deployment.

       You can find out more about the many useful plugins available for Dancer in
       Dancer::Plugins.

EXPORTS

       By default, "use Dancer" exports all the functions below plus sets up your app.  You can
       control the exporting through the normal Exporter mechanism.  For example:

           # Just export the route controllers
           use Dancer qw(get post put patch del);

           # Export everything but pass to avoid clashing with Test::More
           use Test::More;
           use Dancer qw(!pass);

       There are also some special tags to control exports and behaviour.

   :moose
       This will export everything except functions which clash with Moose. Currently these are
       "after" and "before".

   :syntax
       This tells Dancer to just export symbols and not set up your app.  This is most useful for
       writing Dancer code outside of your main route handler.

   :tests
       This will export everything except functions which clash with commonly used testing
       modules. Currently these are "pass".

       It can be combined with other export pragmas. For example, while testing...

           use Test::More;
           use Dancer qw(:syntax :tests);

           # Test::Most also exports "set" and "any"
           use Test::Most;
           use Dancer qw(:syntax :tests !set !any);

           # Alternatively, if you want to use Dancer's set and any...
           use Test::Most qw(!set !any);
           use Dancer qw(:syntax :tests);

   :script
       This will export all the keywords, and will also load the configuration.

       This is useful when you want to use your Dancer application from a script.

           use MyApp;
           use Dancer ':script';
           MyApp::schema('DBSchema')->deploy();

       By default, the warnings pragma will also be exported, meaning your app/script will be
       running under "use warnings".  If you do not want this, set the import_warnings setting to
       a false value.

   !keyword
       If you want to simply prevent Dancer from exporting specific keywords (perhaps you plan to
       implement them yourself in a different way, or you don't plan to use them and they clash
       with another module you're loading), you can simply exclude them:

           use Dancer qw(!session);

       The above would import all keywords as normal, with the exception of "session".

FUNCTIONS

   after
       Deprecated - see the "after" hook.

   any
       Defines a route for multiple HTTP methods at once:

           any ['get', 'post'] => '/myaction' => sub {
               # code
           };

       Or even, a route handler that would match any HTTP methods:

           any '/myaction' => sub {
               # code
           };

   before
       Deprecated - see the "before" hook.

   before_template
       Deprecated - see the "before_template" hook.

   cookies
       Accesses cookies values, it returns a HashRef of Dancer::Cookie objects:

           get '/some_action' => sub {
               my $cookie = cookies->{name};
               return $cookie->value;
           };

       In the case you have stored something else than a Scalar in your cookie:

           get '/some_action' => sub {
               my $cookie = cookies->{oauth};
               my %values = $cookie->value;
               return ($values{token}, $values{token_secret});
           };

   cookie
       Accesses a cookie value (or sets it). Note that this method will eventually be preferred
       over "set_cookie".

           cookie lang => "fr-FR";              # set a cookie and return its value
           cookie lang => "fr-FR", expires => "2 hours";   # extra cookie info
           cookie "lang"                        # return a cookie value

       If your cookie value is a key/value URI string, like

           token=ABC&user=foo

       "cookie" will only return the first part ("token=ABC") if called in scalar context.  Use
       list context to fetch them all:

           my @values = cookie "name";

   config
       Accesses the configuration of the application:

           get '/appname' => sub {
               return "This is " . config->{appname};
           };

   content_type
       Sets the content-type rendered, for the current route handler:

           get '/cat/:txtfile' => sub {
               content_type 'text/plain';

               # here we can dump the contents of param('txtfile')
           };

       You can use abbreviations for content types. For instance:

           get '/svg/:id' => sub {
               content_type 'svg';

               # here we can dump the image with id param('id')
           };

       Note that if you want to change the default content-type for every route, you have to
       change the "content_type" setting instead.

   dance
       Alias for the "start" keyword.

   dancer_version
       Returns the version of Dancer. If you need the major version, do something like:

         int(dancer_version);

   debug
       Logs a message of debug level:

           debug "This is a debug message";

       See Dancer::Logger for details on how to configure where log messages go.

   dirname
       Returns the dirname of the path given:

           my $dir = dirname($some_path);

   engine
       Given a namespace, returns the current engine object

           my $template_engine = engine 'template';
           my $html = $template_engine->apply_renderer(...);
           $template_engine->apply_layout($html);

   error
       Logs a message of error level:

           error "This is an error message";

       See Dancer::Logger for details on how to configure where log messages go.

   false
       Constant that returns a false value (0).

   forward
       Runs an internal redirect of the current request to another request. This helps you avoid
       having to redirect the user using HTTP and set another request to your application.

       It effectively lets you chain routes together in a clean manner.

           get '/demo/articles/:article_id' => sub {

               # you'll have to implement this next sub yourself :)
               change_the_main_database_to_demo();

               forward "/articles/" . params->{article_id};
           };

       In the above example, the users that reach /demo/articles/30 will actually reach
       /articles/30 but we've changed the database to demo before.

       This is pretty cool because it lets us retain our paths and offer a demo database by
       merely going to /demo/....

       You'll notice that in the example we didn't indicate whether it was GET or POST. That is
       because "forward" chains the same type of route the user reached. If it was a GET, it will
       remain a GET (but if you do need to change the method, you can do so; read on below for
       details.)

       WARNING : using forward will not preserve session data set on the forwarding rule.

       WARNING : Issuing a forward immediately exits the current route, and perform the forward.
       Thus, any code after a forward is ignored, until the end of the route. e.g.

           get '/foo/:article_id' => sub {
               if ($condition) {
                   forward "/articles/" . params->{article_id};
                   # The following code is never executed
                   do_stuff();
               }

               more_stuff();
           };

       So it's not necessary anymore to use "return" with forward.

       Note that forward doesn't parse GET arguments. So, you can't use something like:

            return forward '/home?authorized=1';

       But "forward" supports an optional HashRef with parameters to be added to the actual
       parameters:

            return forward '/home', { authorized => 1 };

       Finally, you can add some more options to the forward method, in a third argument, also as
       a HashRef. That option is currently only used to change the method of your request. Use
       with caution.

           return forward '/home', { auth => 1 }, { method => 'POST' };

   from_dumper ($structure)
       Deserializes a Data::Dumper structure.

   from_json ($structure, %options)
       Deserializes a JSON structure. Can receive optional arguments. Those arguments are valid
       JSON arguments to change the behaviour of the default "JSON::from_json" function.

   from_yaml ($structure)
       Deserializes a YAML structure.

   from_xml ($structure, %options)
       Deserializes a XML structure. Can receive optional arguments. These arguments are valid
       XML::Simple arguments to change the behaviour of the default "XML::Simple::XMLin"
       function.

   get
       Defines a route for HTTP GET requests to the given path:

           get '/' => sub {
               return "Hello world";
           }

       Note that a route to match HEAD requests is automatically created as well.

   halt
       Sets a response object with the content given.

       When used as a return value from a filter, this breaks the execution flow and renders the
       response immediately:

           hook before sub {
               if ($some_condition) {
                   halt("Unauthorized");
                   # This code is not executed :
                   do_stuff();
               }
           };

           get '/' => sub {
               "hello there";
           };

       WARNING : Issuing a halt immediately exits the current route, and perform the halt. Thus,
       any code after a halt is ignored, until the end of the route.  So it's not necessary
       anymore to use "return" with halt.

   headers
       Adds custom headers to responses:

           get '/send/headers', sub {
               headers 'X-Foo' => 'bar', X-Bar => 'foo';
           }

   header
       adds a custom header to response:

           get '/send/header', sub {
               header 'x-my-header' => 'shazam!';
           }

       Note that it will overwrite the old value of the header, if any. To avoid that, see
       "push_header".

   push_header
       Do the same as "header", but allow for multiple headers with the same name.

           get '/send/header', sub {
               push_header 'x-my-header' => '1';
               push_header 'x-my-header' => '2';
               will result in two headers "x-my-header" in the response
           }

   hook
       Adds a hook at some position. For example :

         hook before_serializer => sub {
           my $response = shift;
           $response->content->{generated_at} = localtime();
         };

       There can be multiple hooks assigned to a given position, and each will be executed in
       order. Note that all hooks are always called, even if they are defined in a different
       package loaded via "load_app".

       (For details on how to register new hooks from within plugins, see Dancer::Hook.)
       Supported before hooks (in order of execution):

       before_deserializer
           This hook receives no arguments.

             hook before_deserializer => sub {
               ...
             };

       before_file_render
           This hook receives as argument the path of the file to render.

             hook before_file_render => sub {
               my $path = shift;
               ...
             };

       before_error_init
           This hook receives as argument a Dancer::Error object.

             hook before_error_init => sub {
               my $error = shift;
               ...
             };

       before_error_render
           This hook receives as argument a Dancer::Error object.

             hook before_error_render => sub {
               my $error = shift;
             };

       before
           This hook receives one argument, the route being executed (a Dancer::Route object).

             hook before => sub {
               my $route_handler = shift;
               ...
             };

           it is equivalent to the deprecated

             before sub {
               ...
             };

       before_template_render
           This is an alias to 'before_template'.

           This hook receives as argument a HashRef, containing the tokens that will be passed to
           the template. You can use it to add more tokens, or delete some specific token.

             hook before_template_render => sub {
               my $tokens = shift;
               delete $tokens->{user};
               $tokens->{time} = localtime;
             };

           is equivalent to

             hook before_template => sub {
               my $tokens = shift;
               delete $tokens->{user};
               $tokens->{time} = localtime;
             };

       before_layout_render
           This hook receives two arguments. The first one is a HashRef containing the tokens.
           The second is a ScalarRef representing the content of the template.

             hook before_layout_render => sub {
               my ($tokens, $html_ref) = @_;
               ...
             };

       before_serializer
           This hook receives as argument a Dancer::Response object.

             hook before_serializer => sub {
               my $response = shift;
               $response->content->{start_time} = time();
             };

       Supported after hooks (in order of execution):

       after_deserializer
           This hook receives no arguments.

             hook after_deserializer => sub {
               ...
             };

       after_file_render
           This hook receives as argument a Dancer::Response object.

             hook after_file_render => sub {
               my $response = shift;
             };

       after_template_render
           This hook receives as argument a ScalarRef representing the content generated by the
           template.

             hook after_template_render => sub {
               my $html_ref = shift;
             };

       after_layout_render
           This hook receives as argument a ScalarRef representing the content generated by the
           layout

             hook after_layout_render => sub {
               my $html_ref = shift;
             };

       after
           This is an alias for "after".

           This hook runs after a request has been processed, but before the response is sent.

           It receives a Dancer::Response object, which it can modify if it needs to make changes
           to the response which is about to be sent.

             hook after => sub {
               my $response = shift;
             };

           This is equivalent to the deprecated

             after sub {
               my $response = shift;
             };

       after_error_render
           This hook receives as argument a Dancer::Response object.

             hook after_error_render => sub {
               my $response = shift;
             };

       on_handler_exception
           This hook is called when an exception has been caught, at the handler level, just
           before creating and rendering Dancer::Error. This hook receives as argument a
           Dancer::Exception object.

             hook on_handler_exception => sub {
               my $exception = shift;
             };

       on_reset_state
           This hook is called when global state is reset to process a new request.  It receives
           a boolean value that indicates whether the reset was called as part of a forwarded
           request.

             hook on_reset_state => sub {
               my $is_forward = shift;
             };

       on_route_exception
           This hook is called when an exception has been caught, at the route level, just before
           rethrowing it higher. This hook receives the exception as argument. It can be a
           Dancer::Exception, or a string, or whatever was used to "die".

             hook on_route_exception => sub {
               my $exception = shift;
             };

   info
       Logs a message of info level:

           info "This is a info message";

       See Dancer::Logger for details on how to configure where log messages go.

   layout
       This method is deprecated. Use "set":

           set layout => 'user';

   logger
       Deprecated. Use "<set logger => 'console'"> to change current logger engine.

   load
       Loads one or more perl scripts in the current application's namespace. Syntactic sugar
       around Perl's "require":

           load 'UserActions.pl', 'AdminActions.pl';

   load_app
       Loads a Dancer package. This method sets the libdir to the current "./lib" directory:

           # if we have lib/Webapp.pm, we can load it like:
           load_app 'Webapp';
           # or with options
           load_app 'Forum', prefix => '/forum', settings => {foo => 'bar'};

       Note that the package loaded using load_app must import Dancer with the ":syntax" option.

       To load multiple apps repeat load_app:

           load_app 'one';
           load_app 'two';

       The old way of loading multiple apps in one go (load_app 'one', 'two';) is deprecated.

   mime
       Shortcut to access the instance object of Dancer::MIME. You should read the Dancer::MIME
       documentation for full details, but the most commonly-used methods are summarized below:

           # set a new mime type
           mime->add_type( foo => 'text/foo' );

           # set a mime type alias
           mime->add_alias( f => 'foo' );

           # get mime type for an alias
           my $m = mime->for_name( 'f' );

           # get mime type for a file (based on extension)
           my $m = mime->for_file( "foo.bar" );

           # get current defined default mime type
           my $d = mime->default;

           # set the default mime type using config.yml
           # or using the set keyword
           set default_mime_type => 'text/plain';

   params
       This method should be called from a route handler.  It's an alias for the Dancer::Request
       params accessor. It returns an hash reference to all defined parameters. Check "param"
       below to access quickly to a single parameter value.

   param
       This method should be called from a route handler.  This method is an accessor to the
       parameters hash table.

          post '/login' => sub {
              my $username = param "user";
              my $password = param "pass";
              # ...
          }

   pass
       This method should be called from a route handler.  Tells Dancer to pass the processing of
       the request to the next matching route.

       WARNING : Issuing a pass immediately exits the current route, and perform the pass. Thus,
       any code after a pass is ignored, until the end of the route.  So it's not necessary
       anymore to use "return" with pass.

           get '/some/route' => sub {
               if (...) {
                   # we want to let the next matching route handler process this one
                   pass(...);
                   # This code will be ignored
                   do_stuff();
               }
           };

   patch
       Defines a route for HTTP PATCH requests to the given URL:

           patch '/resource' => sub { ... };

       ("PATCH" is a relatively new and not-yet-common HTTP verb, which is intended to work as a
       "partial-PUT", transferring just the changes; please see
       <http://tools.ietf.org/html/rfc5789|RFC5789> for further details.)

       Please be aware that, if you run your app in standalone mode, "PATCH" requests will not
       reach your app unless you have a new version of HTTP::Server::Simple which accepts "PATCH"
       as a valid verb.  The current version at time of writing, 0.44, does not.  A pull request
       has been submitted to add this support, which you can find at:

       <https://github.com/bestpractical/http-server-simple/pull/1>

   path
       Concatenates multiple paths together, without worrying about the underlying operating
       system:

           my $path = path(dirname($0), 'lib', 'File.pm');

       It also normalizes (cleans) the path aesthetically. It does not verify the path exists.

   post
       Defines a route for HTTP POST requests to the given URL:

           post '/' => sub {
               return "Hello world";
           }

   prefix
       Defines a prefix for each route handler, like this:

           prefix '/home';

       From here, any route handler is defined to /home/*:

           get '/page1' => sub {}; # will match '/home/page1'

       You can unset the prefix value:

           prefix undef;
           get '/page1' => sub {}; will match /page1

       For a safer alternative you can use lexical prefix like this:

           prefix '/home' => sub {
               ## Prefix is set to '/home' here

               get ...;
               get ...;
           };
           ## prefix reset to the previous version here

       This makes it possible to nest prefixes:

          prefix '/home' => sub {
              ## some routes

             prefix '/private' => sub {
                ## here we are under /home/private...

                ## some more routes
             };
             ## back to /home
          };
          ## back to the root

       Notice: once you have a prefix set, do not add a caret to the regex:

           prefix '/foo';
           get qr{^/bar} => sub { ... } # BAD BAD BAD
           get qr{/bar}  => sub { ... } # Good!

   del
       Defines a route for HTTP DELETE requests to the given URL:

           del '/resource' => sub { ... };

   options
       Defines a route for HTTP OPTIONS requests to the given URL:

           options '/resource' => sub { ... };

   put
       Defines a route for HTTP PUT requests to the given URL:

           put '/resource' => sub { ... };

   redirect
       Generates a HTTP redirect (302).  You can either redirect to a complete different site or
       within the application:

           get '/twitter', sub {
               redirect 'http://twitter.com/me';
           };

       You can also force Dancer to return a specific 300-ish HTTP response code:

           get '/old/:resource', sub {
               redirect '/new/'.params->{resource}, 301;
           };

       It is important to note that issuing a redirect by itself does not exit and redirect
       immediately, redirection is deferred until after the current route or filter has been
       processed. To exit and redirect immediately, use the return function, e.g.

           get '/restricted', sub {
               return redirect '/login' if accessDenied();
               return 'Welcome to the restricted section';
           };

   render_with_layout
       Allows a handler to provide plain HTML (or other content), but have it rendered within the
       layout still.

       This method is DEPRECATED, and will be removed soon. Instead, you should be using the
       "engine" keyword:

           get '/foo' => sub {
               # Do something which generates HTML directly (maybe using
               # HTML::Table::FromDatabase or something)
               my $content = ...;

               # get the template engine
               my $template_engine = engine 'template';

               # apply the layout (not the renderer), and return the result
               $template_engine->apply_layout($content)
           };

       It works very similarly to "template" in that you can pass tokens to be used in the
       layout, and/or options to control the way the layout is rendered.  For instance, to use a
       custom layout:

           render_with_layout $content, {}, { layout => 'layoutname' };

   request
       Returns a Dancer::Request object representing the current request.

       See the Dancer::Request documentation for the methods you can call, for example:

           request->referer;         # value of the HTTP referer header
           request->remote_address;  # user's IP address
           request->user_agent;      # User-Agent header value

   send_error
       Returns a HTTP error.  By default the HTTP code returned is 500:

           get '/photo/:id' => sub {
               if (...) {
                   send_error("Not allowed", 403);
               } else {
                  # return content
               }
           }

       WARNING : Issuing a send_error immediately exits the current route, and perform the
       send_error. Thus, any code after a send_error is ignored, until the end of the route.  So
       it's not necessary anymore to use "return" with send_error.

           get '/some/route' => sub {
               if (...) {
                   # we want to let the next matching route handler process this one
                   send_error(..);
                   # This code will be ignored
                   do_stuff();
               }
           };

   send_file
       Lets the current route handler send a file to the client. Note that the path of the file
       must be relative to the public directory unless you use the "system_path" option (see
       below).

           get '/download/:file' => sub {
               return send_file(params->{file});
           }

       WARNING : Issuing a send_file immediately exits the current route, and perform the
       send_file. Thus, any code after a send_file is ignored, until the end of the route.  So
       it's not necessary anymore to use "return" with send_file.

           get '/some/route' => sub {
               if (...) {
                   # we want to let the next matching route handler process this one
                   send_file(...);
                   # This code will be ignored
                   do_stuff();
               }
           };

       Send file supports streaming possibility using PSGI streaming. The server should support
       it but normal streaming is supported on most, if not all.

           get '/download/:file' => sub {
               return send_file( params->{file}, streaming => 1 );
           }

       You can control what happens using callbacks.

       First, "around_content" allows you to get the writer object and the chunk of content read,
       and then decide what to do with each chunk:

           get '/download/:file' => sub {
               return send_file(
                   params->{file},
                   streaming => 1,
                   callbacks => {
                       around_content => sub {
                           my ( $writer, $chunk ) = @_;
                           $writer->write("* $chunk");
                       },
                   },
               );
           }

       You can use "around" to all get all the content (whether a filehandle if it's a regular
       file or a full string if it's a scalar ref) and decide what to do with it:

           get '/download/:file' => sub {
               return send_file(
                   params->{file},
                   streaming => 1,
                   callbacks => {
                       around => sub {
                           my ( $writer, $content ) = @_;

                           # we know it's a text file, so we'll just stream
                           # line by line
                           while ( my $line = <$content> ) {
                               $writer->write($line);
                           }
                       },
                   },
               );
           }

       Or you could use "override" to control the entire streaming callback request:

           get '/download/:file' => sub {
               return send_file(
                   params->{file},
                   streaming => 1,
                   callbacks => {
                       override => sub {
                           my ( $respond, $response ) = @_;

                           my $writer = $respond->( [ $newstatus, $newheaders ] );
                           $writer->write("some line");
                       },
                   },
               );
           }

       You can also set the number of bytes that will be read at a time (default being 42K bytes)
       using "bytes":

           get '/download/:file' => sub {
               return send_file(
                   params->{file},
                   streaming => 1,
                   bytes     => 524288, # 512K
               );
           };

       The content-type will be set depending on the current MIME types definition (see "mime" if
       you want to define your own).

       If your filename does not have an extension, or you need to force a specific mime type,
       you can pass it to "send_file" as follows:

           return send_file(params->{file}, content_type => 'image/png');

       Also, you can use your aliases or file extension names on "content_type", like this:

           return send_file(params->{file}, content_type => 'png');

       For files outside your public folder, you can use the "system_path" switch. Just bear in
       mind that its use needs caution as it can be dangerous.

          return send_file('/etc/passwd', system_path => 1);

       If you have your data in a scalar variable, "send_file" can be useful as well. Pass a
       reference to that scalar, and "send_file" will behave as if there was a file with that
       contents:

          return send_file( \$data, content_type => 'image/png' );

       Note that Dancer is unable to guess the content type from the data contents. Therefore you
       might need to set the "content_type" properly. For this kind of usage an attribute named
       "filename" can be useful.  It is used as the Content-Disposition header, to hint the
       browser about the filename it should use.

          return send_file( \$data, content_type => 'image/png'
                                    filename     => 'onion.png' );

       Note that you should always use "return send_file ..." to stop execution of your route
       handler at that point.

   set
       Defines a setting:

           set something => 'value';

       You can set more than one value at once:

           set something => 'value', otherthing => 'othervalue';

   setting
       Returns the value of a given setting:

           setting('something'); # 'value'

   set_cookie
       Creates or updates cookie values:

           get '/some_action' => sub {
               set_cookie name => 'value',
                          expires => (time + 3600),
                          domain  => '.foo.com';
           };

       In the example above, only 'name' and 'value' are mandatory.

       You can also store more complex structure in your cookies:

           get '/some_auth' => sub {
               set_cookie oauth => {
                   token        => $twitter->request_token,
                   token_secret => $twitter->secret_token,
                   ...
               };
           };

       You can't store more complex structure than this. All keys in the HashRef should be
       Scalars; storing references will not work.

       See Dancer::Cookie for further options when creating your cookie.

       Note that this method will be eventually deprecated in favor of the new "cookie" method.

   session
       Provides access to all data stored in the user's session (if any).

       It can also be used as a setter to store data in the session:

           # getter example
           get '/user' => sub {
               if (session('user')) {
                   return "Hello, ".session('user')->name;
               }
           };

           # setter example
           post '/user/login' => sub {
               ...
               if ($logged_in) {
                   session user => $user;
               }
               ...
           };

       You may also need to clear a session:

           # destroy session
           get '/logout' => sub {
               ...
               session->destroy;
               ...
           };

       If you need to fetch the session ID being used for any reason:

           my $id = session->id;

   splat
       Returns the list of captures made from a route handler with a route pattern which includes
       wildcards:

           get '/file/*.*' => sub {
               my ($file, $extension) = splat;
               ...
           };

       There is also the extensive splat (A.K.A. "megasplat"), which allows extensive greedier
       matching, available using two asterisks. The additional path is broken down and returned
       as an ArrayRef:

           get '/entry/*/tags/**' => sub {
               my ( $entry_id, $tags ) = splat;
               my @tags = @{$tags};
           };

       This helps with chained actions:

           get '/team/*/**' => sub {
               my ($team) = splat;
               var team => $team;
               pass;
           };

           prefix '/team/*';

           get '/player/*' => sub {
               my ($player) = splat;

               # etc...
           };

           get '/score' => sub {
               return score_for( vars->{'team'} );
           };

   start
       Starts the application or the standalone server (depending on the deployment choices).

       This keyword should be called at the very end of the script, once all routes are defined.
       At this point, Dancer takes over control.

   status
       Changes the status code provided by an action.  By default, an action will produce an
       "HTTP 200 OK" status code, meaning everything is OK:

           get '/download/:file' => {
               if (! -f params->{file}) {
                   status 'not_found';
                   return "File does not exist, unable to download";
               }
               # serving the file...
           };

       In that example, Dancer will notice that the status has changed, and will render the
       response accordingly.

       The status keyword receives either a numeric status code or its name in lower case, with
       underscores as a separator for blanks - see the list in "HTTP CODES" in Dancer::HTTP.

   template
       Returns the response of processing the given template with the given parameters (and
       optional settings), wrapping it in the default or specified layout too, if layouts are in
       use.

       An example of a  route handler which returns the result of using template to build a
       response with the current template engine:

           get '/' => sub {
               ...
               return template 'some_view', { token => 'value'};
           };

       Note that "template" simply returns the content, so when you use it in a route handler, if
       execution of the route handler should stop at that point, make sure you use 'return' to
       ensure your route handler returns the content.

       Since template just returns the result of rendering the template, you can also use it to
       perform other templating tasks, e.g. generating emails:

           post '/some/route' => sub {
               if (...) {
                   email {
                       to      => 'someone@example.com',
                       from    => 'foo@example.com',
                       subject => 'Hello there',
                       msg     => template('emails/foo', { name => params->{name} }),
                   };

                   return template 'message_sent';
               } else {
                   return template 'error';
               }
           };

       Compatibility notice: "template" was changed in version 1.3090 to immediately interrupt
       execution of a route handler and return the content, as it's typically used at the end of
       a route handler to return content.  However, this caused issues for some people who were
       using "template" to generate emails etc, rather than accessing the template engine
       directly, so this change has been reverted in 1.3091.

       The first parameter should be a template available in the views directory, the second one
       (optional) is a HashRef of tokens to interpolate, and the third (again optional) is a
       HashRef of options.

       For example, to disable the layout for a specific request:

           get '/' => sub {
               template 'index', {}, { layout => undef };
           };

       Or to request a specific layout, of course:

           get '/user' => sub {
               template 'user', {}, { layout => 'user' };
           };

       Some tokens are automatically added to your template ("perl_version", "dancer_version",
       "settings", "request", "params", "vars" and, if you have sessions enabled, "session").
       Check Dancer::Template::Abstract for further details.

   to_dumper ($structure)
       Serializes a structure with Data::Dumper.

   to_json ($structure, %options)
       Serializes a structure to JSON. Can receive optional arguments. Thoses arguments are valid
       JSON arguments to change the behaviour of the default "JSON::to_json" function.

   to_yaml ($structure)
       Serializes a structure to YAML.

   to_xml ($structure, %options)
       Serializes a structure to XML. Can receive optional arguments. Thoses arguments are valid
       XML::Simple arguments to change the behaviour of the default "XML::Simple::XMLout"
       function.

   true
       Constant that returns a true value (1).

   upload
       Provides access to file uploads.  Any uploaded file is accessible as a
       Dancer::Request::Upload object. You can access all parsed uploads via:

           post '/some/route' => sub {
               my $file = upload('file_input_foo');
               # file is a Dancer::Request::Upload object
           };

       If you named multiple input of type "file" with the same name, the upload keyword will
       return an Array of Dancer::Request::Upload objects:

           post '/some/route' => sub {
               my ($file1, $file2) = upload('files_input');
               # $file1 and $file2 are Dancer::Request::Upload objects
           };

       You can also access the raw HashRef of parsed uploads via the current request object:

           post '/some/route' => sub {
               my $all_uploads = request->uploads;
               # $all_uploads->{'file_input_foo'} is a Dancer::Request::Upload object
               # $all_uploads->{'files_input'} is an ArrayRef of Dancer::Request::Upload objects
           };

       Note that you can also access the filename of the upload received via the params keyword:

           post '/some/route' => sub {
               # params->{'files_input'} is the filename of the file uploaded
           };

       See Dancer::Request::Upload for details about the interface provided.

   uri_for
       Returns a fully-qualified URI for the given path:

           get '/' => sub {
               redirect uri_for('/path');
               # can be something like: http://localhost:3000/path
           };

   captures
       Returns a reference to a copy of "%+", if there are named captures in the route Regexp.

       Named captures are a feature of Perl 5.10, and are not supported in earlier versions:

           get qr{
               / (?<object> user   | ticket | comment )
               / (?<action> delete | find )
               / (?<id> \d+ )
               /?$
           }x
           , sub {
               my $value_for = captures;
               "i don't want to $$value_for{action} the $$value_for{object} $$value_for{id} !"
           };

   var
       Provides an accessor for variables shared between filters and route handlers.  Given a
       key/value pair, it sets a variable:

           hook before sub {
               var foo => 42;
           };

       Later, route handlers and other filters will be able to read that variable:

           get '/path' => sub {
               my $foo = var 'foo';
               ...
           };

   vars
       Returns the HashRef of all shared variables set during the filter/route chain with the
       "var" keyword:

           get '/path' => sub {
               if (vars->{foo} eq 42) {
                   ...
               }
           };

   warning
       Logs a warning message through the current logger engine:

           warning "This is a warning";

       See Dancer::Logger for details on how to configure where log messages go.

AUTHOR

       This module has been written by Alexis Sukrieh <sukria@cpan.org> and others, see the
       AUTHORS file that comes with this distribution for details.

SOURCE CODE

       The source code for this module is hosted on GitHub
       <https://github.com/PerlDancer/Dancer>.  Feel free to fork the repository and submit pull
       requests!  (See Dancer::Development for details on how to contribute).

       Also, why not watch the repo <https://github.com/PerlDancer/Dancer/toggle_watch> to keep
       up to date with the latest upcoming changes?

GETTING HELP / CONTRIBUTING

       The Dancer development team can be found on #dancer on irc.perl.org:
       <irc://irc.perl.org/dancer>

       If you don't have an IRC client installed/configured, there is a simple web chat client at
       <http://www.perldancer.org/irc> for you.

       There is also a Dancer users mailing list available - subscribe at:

       <http://lists.preshweb.co.uk/mailman/listinfo/dancer-users>

       If you'd like to contribute to the Dancer project, please see
       <http://www.perldancer.org/contribute> for all the ways you can help!

DEPENDENCIES

       The following modules are mandatory (Dancer cannot run without them):

       HTTP::Server::Simple::PSGI
       HTTP::Body
       LWP
       MIME::Types
       URI

       The following modules are optional:

       JSON : needed to use JSON serializer
       Plack : in order to use PSGI
       Template : in order to use TT for rendering views
       XML::Simple and <XML:SAX> or <XML:Parser> for XML serialization
       YAML : needed for configuration file support

LICENSE

       This module is free software and is published under the same terms as Perl itself.

SEE ALSO

       Main Dancer web site: <http://perldancer.org/>.

       The concept behind this module comes from the Sinatra ruby project, see
       <http://www.sinatrarb.com/> for details.