README

NAME
    Dancer - lightweight yet powerful web application framework

VERSION
    version 1.3131

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. In list context it returns a list
    of key/value pair of all defined parameters. In scalar context, it
    returns a hash reference instead. 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;

    In order to be able to use sessions, first you need to enable session
    support in one of the configuration files. A quick way to do it is to
    add

        session: "YAML"

    to config.yml.

    For more details, see Dancer::Session.

  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

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.

AUTHOR
    Dancer Core Developers

COPYRIGHT AND LICENSE
    This software is copyright (c) 2010 by Alexis Sukrieh.

    This is free software; you can redistribute it and/or modify it under
    the same terms as the Perl 5 programming language system itself.