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NAME

       Mojolicious::Guides::Routing - Routing

OVERVIEW

       This document contains a simple and fun introduction to the Mojolicious router and its underlying
       concepts.

CONCEPTS

       Essentials every Mojolicious developer should know.

   Dispatcher
       The foundation of every web framework is a tiny black box connecting incoming requests with code
       generating the appropriate response.

         GET /user/show/1 -> $c->render(text => 'Sebastian');

       This black box is usually called a dispatcher. There are many implementations using different strategies
       to establish these connections, but pretty much all are based around mapping the path part of the request
       URL to some kind of response generator.

         /user/show/2 -> $c->render(text => 'Daniel');
         /user/show/3 -> $c->render(text => 'Sara');
         /user/show/4 -> $c->render(text => 'Baerbel');
         /user/show/5 -> $c->render(text => 'Wolfgang');

       While it is very well possible to make all these connections static, it is also rather inefficient.
       That's why regular expressions are commonly used to make the dispatch process more dynamic.

         qr!/user/show/(\d+)! -> $c->render(text => $users{$1});

       Modern dispatchers have pretty much everything HTTP has to offer at their disposal and can use many more
       variables than just the request path, such as request method and headers like "Host", "User-Agent" and
       "Accept".

         GET /user/show/23 HTTP/1.1
         Host: mojolicio.us
         User-Agent: Mojolicious (Perl)
         Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8

   Routes
       While regular expressions are quite powerful they also tend to be unpleasant to look at and are generally
       overkill for ordinary path matching.

         qr!/user/show/(\d+)! -> $c->render(text => $users{$1});

       This is where routes come into play, they have been designed from the ground up to represent paths with
       placeholders.

         /user/show/:id -> $c->render(text => $users{$id});

       The only difference between a static path and the route above is the ":id" placeholder. One or more
       placeholders can be anywhere in the route.

         /user/:action/:id

       A fundamental concept of the Mojolicious router is that extracted placeholder values are turned into a
       hash.

         /user/show/23 -> /user/:action/:id -> {action => 'show', id => 23}

       This hash is basically the center of every Mojolicious application, you will learn more about this later
       on. Internally routes get compiled to regular expressions, so you can get the best of both worlds with a
       little bit of experience.

         /user/show/:id -> qr/(?-xism:^\/user\/show/([^\/.]+))/

       A trailing slash in the path is always optional.

         /user/show/23/ -> /user/:action/:id -> {action => 'show', id => 23}

   Reversibility
       One more huge advantage routes have over regular expressions is that they are easily reversible,
       extracted placeholders can be turned back into a path at any time.

         /sebastian -> /:name -> {name => 'sebastian'}
         {name => 'sebastian'} -> /:name -> /sebastian

       Every placeholder has a name, even if it's just an empty string.

   Standard placeholders
       Standard placeholders are the simplest form of placeholders, they use a colon prefix and match all
       characters except "/" and ".", similar to the regular expression "([^/.]+)".

         /hello              -> /:name/hello -> undef
         /sebastian/23/hello -> /:name/hello -> undef
         /sebastian.23/hello -> /:name/hello -> undef
         /sebastian/hello    -> /:name/hello -> {name => 'sebastian'}
         /sebastian23/hello  -> /:name/hello -> {name => 'sebastian23'}
         /sebastian 23/hello -> /:name/hello -> {name => 'sebastian 23'}

       All placeholders can be surrounded by parentheses to separate them from the surrounding text.

         /hello             -> /(:name)hello -> undef
         /sebastian/23hello -> /(:name)hello -> undef
         /sebastian.23hello -> /(:name)hello -> undef
         /sebastianhello    -> /(:name)hello -> {name => 'sebastian'}
         /sebastian23hello  -> /(:name)hello -> {name => 'sebastian23'}
         /sebastian 23hello -> /(:name)hello -> {name => 'sebastian 23'}

       The colon prefix is optional for standard placeholders that are surrounded by parentheses.

         /i♥mojolicious -> /(one)♥(two) -> {one => 'i', two => 'mojolicious'}

   Relaxed placeholders
       Relaxed placeholders are just like standard placeholders, but use a hash prefix and match all characters
       except "/", similar to the regular expression "([^/]+)".

         /hello              -> /#name/hello -> undef
         /sebastian/23/hello -> /#name/hello -> undef
         /sebastian.23/hello -> /#name/hello -> {name => 'sebastian.23'}
         /sebastian/hello    -> /#name/hello -> {name => 'sebastian'}
         /sebastian23/hello  -> /#name/hello -> {name => 'sebastian23'}
         /sebastian 23/hello -> /#name/hello -> {name => 'sebastian 23'}

       They can be especially useful for manually matching file names with extensions, rather than using format
       detection.

         /music/song.mp3 -> /music/#filename -> {filename => 'song.mp3'}

   Wildcard placeholders
       Wildcard placeholders are just like the two types of placeholders above, but use an asterisk prefix and
       match absolutely everything, including "/" and ".", similar to the regular expression "(.+)".

         /hello              -> /*name/hello -> undef
         /sebastian/23/hello -> /*name/hello -> {name => 'sebastian/23'}
         /sebastian.23/hello -> /*name/hello -> {name => 'sebastian.23'}
         /sebastian/hello    -> /*name/hello -> {name => 'sebastian'}
         /sebastian23/hello  -> /*name/hello -> {name => 'sebastian23'}
         /sebastian 23/hello -> /*name/hello -> {name => 'sebastian 23'}

BASICS

       Most commonly used features every Mojolicious developer should know about.

   Minimal route
       The attribute "routes" in Mojolicious contains a router you can use to generate route structures, they
       match in the same order in which they were defined.

         # Application
         package MyApp;
         use Mojo::Base 'Mojolicious';

         sub startup {
           my $self = shift;

           # Router
           my $r = $self->routes;

           # Route
           $r->get('/welcome')->to(controller => 'foo', action => 'welcome');
         }

         1;

       The minimal route above will load and instantiate the class "MyApp::Controller::Foo" and call its
       "welcome" method.

         # Controller
         package MyApp::Controller::Foo;
         use Mojo::Base 'Mojolicious::Controller';

         # Action
         sub welcome {
           my $self = shift;

           # Render response
           $self->render(text => 'Hello there.');
         }

         1;

       Routes are usually configured in the "startup" method of the application class, but the router can be
       accessed from everywhere (even at runtime).

   Routing destination
       After you start a new route with methods like "get" in Mojolicious::Routes::Route, you can also give it a
       destination in the form of a hash using the chained method "to" in Mojolicious::Routes::Route.

         # /welcome -> {controller => 'foo', action => 'welcome'}
         $r->get('/welcome')->to(controller => 'foo', action => 'welcome');

       Now if the route matches an incoming request it will use the content of this hash to try and find
       appropriate code to generate a response.

   HTTP methods
       There are already shortcuts for the most common HTTP request methods like "post" in
       Mojolicious::Routes::Route, and for more control "any" in Mojolicious::Routes::Route accepts an optional
       array reference with arbitrary request methods as first argument.

         # PUT /hello  -> undef
         # GET /hello  -> {controller => 'foo', action => 'hello'}
         $r->get('/hello')->to(controller => 'foo', action => 'hello');

         # PUT /hello -> {controller => 'foo', action => 'hello'}
         $r->put('/hello')->to(controller => 'foo', action => 'hello');

         # POST /hello -> {controller => 'foo', action => 'hello'}
         $r->post('/hello')->to(controller => 'foo', action => 'hello');

         # GET|POST /bye  -> {controller => 'foo', action => 'bye'}
         $r->any([qw(GET POST)] => '/bye')->to(controller => 'foo', action => 'bye');

         # * /whatever -> {controller => 'foo', action => 'whatever'}
         $r->any('/whatever')->to(controller => 'foo', action => 'whatever');

       There is one small exception, "HEAD" requests are considered equal to "GET", but content will not be sent
       with the response even if it is present.

         # GET /test  -> {controller => 'bar', action => 'test'}
         # HEAD /test -> {controller => 'bar', action => 'test'}
         $r->get('/test')->to(controller => 'bar', action => 'test');

       You can also use the "_method" query parameter to override the request method, this can be very useful
       when submitting forms with browsers that only support "GET" and "POST".

         # PUT  /stuff             -> {controller => 'baz', action => 'stuff'}
         # POST /stuff?_method=PUT -> {controller => 'baz', action => 'stuff'}
         $r->put('/stuff')->to(controller => 'baz', action => 'stuff');

   IRIs
       IRIs are handled transparently, that means paths are guaranteed to be unescaped and decoded from bytes to
       characters.

         # GET /☃ (Unicode snowman) -> {controller => 'foo', action => 'snowman'}
         $r->get('/☃')->to(controller => 'foo', action => 'snowman');

   Stash
       The generated hash of a matching route is actually the center of the whole Mojolicious request cycle. We
       call it the stash, and it persists until a response has been generated.

         # /bye -> {controller => 'foo', action => 'bye', mymessage => 'Bye'}
         $r->get('/bye')
           ->to(controller => 'foo', action => 'bye', mymessage => 'Bye');

       There are a few stash values with special meaning, such as "controller" and "action", but you can
       generally fill it with whatever data you need to generate a response. Once dispatched the whole stash
       content can be changed at any time.

         sub bye {
           my $self = shift;

           # Get message from stash
           my $msg = $self->stash('mymessage');

           # Change message in stash
           $self->stash(mymessage => 'Welcome');
         }

       For a full list of reserved stash values see "stash" in Mojolicious::Controller.

   Nested routes
       It is also possible to build tree structures from routes to remove repetitive code. A route with children
       can't match on its own though, only the actual endpoints of these nested routes can.

         # /foo     -> undef
         # /foo/bar -> {controller => 'foo', action => 'bar'}
         my $foo = $r->any('/foo')->to(controller => 'foo');
         $foo->get('/bar')->to(action => 'bar');

       The stash is simply inherited from route to route and newer values override old ones.

         # /cats      -> {controller => 'cats', action => 'index'}
         # /cats/nyan -> {controller => 'cats', action => 'nyan'}
         # /cats/lol  -> {controller => 'cats', action => 'default'}
         my $cats = $r->any('/cats')->to(controller => 'cats', action => 'default');
         $cats->get('/')->to(action => 'index');
         $cats->get('/nyan')->to(action => 'nyan');
         $cats->get('/lol');

   Special stash values
       When the dispatcher sees "controller" and "action" values in the stash it will always try to turn them
       into a class and method to dispatch to. The "controller" value gets converted from "snake_case" to
       "CamelCase" using "camelize" in Mojo::Util and appended to one or more namespaces, defaulting to a
       controller namespace based on the application class ("MyApp::Controller"), as well as the bare
       application class ("MyApp"), and these namespaces are searched in that order. The action value is not
       changed at all, so both values are case-sensitive.

         # Application
         package MyApp;
         use Mojo::Base 'Mojolicious';

         sub startup {
           my $self = shift;

           # /bye -> MyApp::Controller::Foo->bye
           $self->routes->get('/bye')->to(controller => 'foo', action => 'bye');
         }

         1;

         # Controller
         package MyApp::Controller::Foo;
         use Mojo::Base 'Mojolicious::Controller';

         # Action
         sub bye {
           my $self = shift;

           # Render response
           $self->render(text => 'Good bye.');
         }

         1;

       Controller classes are perfect for organizing code in larger projects. There are more dispatch
       strategies, but because controllers are the most commonly used ones they also got a special shortcut in
       the form of "controller#action".

         # /bye -> {controller => 'foo', action => 'bye', mymessage => 'Bye'}
         $r->get('/bye')->to('foo#bye', mymessage => 'Bye');

       During camelization "-" characters get replaced with "::", this allows multi-level "controller"
       hierarchies.

         # / -> MyApp::Controller::Foo::Bar->hi
         $r->get('/')->to('foo-bar#hi');

       You can also just specify the "controller" in CamelCase form instead of snake_case.

         # / -> MyApp::Controller::Foo::Bar->hi
         $r->get('/')->to('Foo::Bar#hi');

       For security reasons the dispatcher will always check if the "controller" is actually a subclass of
       Mojolicious::Controller or Mojo before dispatching to it.

   Namespaces
       You can use the "namespace" stash value to change the namespace of a whole route with all its children.

         # /bye -> MyApp::MyController::Foo::Bar->bye
         $r->get('/bye')
           ->to(namespace => 'MyApp::MyController::Foo::Bar', action => 'bye');

       The "controller" is always converted from "snake_case" to "CamelCase" with "camelize" in Mojo::Util, and
       then appended to this "namespace".

         # /bye -> MyApp::MyController::Foo::Bar->bye
         $r->get('/bye')->to('foo-bar#bye', namespace => 'MyApp::MyController');

         # /hey -> MyApp::MyController::Foo::Bar->hey
         $r->get('/hey')->to('Foo::Bar#hey', namespace => 'MyApp::MyController');

       You can also change the default namespaces for all routes in the application with the router attribute
       "namespaces" in Mojolicious::Routes, which usually defaults to a namespace based on the application class
       ("MyApp::Controller"), as well as the bare application class ("MyApp").

         $r->namespaces(['MyApp::MyController']);

   Route to callback
       The "cb" stash value, which won't be inherited by nested routes, can be used to bypass controllers and
       execute a callback instead.

         $r->get('/bye')->to(cb => sub {
           my $c = shift;
           $c->render(text => 'Good bye.');
         });

       But just like in Mojolicious::Lite you can also pass the callback directly, which usually looks much
       better.

         $r->get('/bye' => sub {
           my $c = shift;
           $c->render(text => 'Good bye.');
         });

   Named routes
       Naming your routes will allow backreferencing in many methods and helpers throughout the whole framework,
       most of them internally rely on "url_for" in Mojolicious::Controller for this.

         # /foo/marcus -> {controller => 'foo', action => 'bar', user => 'marcus'}
         $r->get('/foo/:user')->to('foo#bar')->name('baz');

         # Generate URL "/foo/marcus" for route "baz"
         my $url = $c->url_for('baz');

         # Generate URL "/foo/jan" for route "baz"
         my $url = $c->url_for('baz', user => 'jan');

         # Generate URL "http://127.0.0.1:3000/foo/jan" for route "baz"
         my $url = $c->url_for('baz', user => 'jan')->to_abs;

       You can assign a name with "name" in Mojolicious::Routes::Route, or let the router generate one
       automatically, which would be equal to the route itself without non-word characters, custom names have a
       higher precedence though.

         # /foo/bar ("foobar")
         $r->get('/foo/bar')->to('test#stuff');

         # Generate URL "/foo/bar"
         my $url = $c->url_for('foobar');

       To refer to the current route you can use the reserved name "current" or no name at all.

         # Generate URL for current route
         my $url = $c->url_for('current');
         my $url = $c->url_for;

       To check or get the name of the current route you can use the helper "current_route" in
       Mojolicious::Plugin::DefaultHelpers.

         # Name for current route
         my $name = $c->current_route;

         # Check route name in code shared by multiple routes
         $c->stash(button => 'green') if $c->current_route('login');

   Optional placeholders
       Extracted placeholder values will simply redefine older stash values if they already exist.

         # /bye -> {controller => 'foo', action => 'bar', mymessage => 'bye'}
         # /hey -> {controller => 'foo', action => 'bar', mymessage => 'hey'}
         $r->get('/:mymessage')->to('foo#bar', mymessage => 'hi');

       One more interesting effect, a placeholder automatically becomes optional if there is already a stash
       value of the same name present, this works similar to the regular expression "([^/.]+)?".

         # / -> {controller => 'foo', action => 'bar', mymessage => 'hi'}
         $r->get('/:mymessage')->to('foo#bar', mymessage => 'hi');

         # /test/123     -> {controller => 'foo', action => 'bar', mymessage => 'hi'}
         # /test/bye/123 -> {controller => 'foo', action => 'bar', mymessage => 'bye'}
         $r->get('/test/:mymessage/123')->to('foo#bar', mymessage => 'hi');

       And if two optional placeholders are only separated by a slash, that slash can become optional as well.

         # /           -> {controller => 'foo',   action => 'bar'}
         # /users      -> {controller => 'users', action => 'bar'}
         # /users/list -> {controller => 'users', action => 'list'}
         $r->get('/:controller/:action')->to('foo#bar');

       Special stash values like "controller" and "action" can also be placeholders, which is very convenient
       especially during development, but should only be used very carefully, because every controller method
       becomes a potential route. All uppercase methods as well as those starting with an underscore are
       automatically hidden from the router and you can use "hide" in Mojolicious::Routes to add additional
       ones.

         # Hide "create" method in all controllers
         $r->hide('create');

       This has already been done for all attributes and methods from Mojolicious::Controller.

   More restrictive placeholders
       A very easy way to make placeholders more restrictive are alternatives, you just make a list of possible
       values, which then work similar to the regular expression "(bender|leela)".

         # /fry    -> undef
         # /bender -> {controller => 'foo', action => 'bar', name => 'bender'}
         # /leela  -> {controller => 'foo', action => 'bar', name => 'leela'}
         $r->get('/:name' => [name => [qw(bender leela)]])->to('foo#bar');

       You can also adjust the regular expressions behind placeholders directly, just make sure not to use "^"
       and "$" or capturing groups "(...)", because placeholders become part of a larger regular expression
       internally, "(?:...)"  is fine though.

         # /23   -> {controller => 'foo', action => 'bar', number => 23}
         # /test -> undef
         $r->get('/:number' => [number => qr/\d+/])->to('foo#bar');

         # /23   -> undef
         # /test -> {controller => 'foo', action => 'bar', name => 'test'}
         $r->get('/:name' => [name => qr/[a-zA-Z]+/])->to('foo#bar');

       This way you get easily readable routes and the raw power of regular expressions.

   Under
       To share code with multiple nested routes you can use "under" in Mojolicious::Routes::Route, because
       unlike normal nested routes, the routes generated with it have their own intermediate destination and
       result in additional dispatch cycles when they match.

         # /foo     -> undef
         # /foo/bar -> {controller => 'foo', action => 'baz'}
         #             {controller => 'foo', action => 'bar'}
         my $foo = $r->under('/foo')->to('foo#baz');
         $foo->get('/bar')->to('#bar');

       The actual action code for this destination needs to return a true value or the dispatch chain will be
       broken, this can be a very powerful tool for authentication.

         # /blackjack -> {cb => sub {...}}
         #               {controller => 'hideout', action => 'blackjack'}
         my $auth = $r->under('/' => sub {
           my $c = shift;

           # Authenticated
           return 1 if $c->req->headers->header('X-Bender');

           # Not authenticated
           $c->render(text => "You're not Bender.");
           return undef;
         });
         $auth->get('/blackjack')->to('hideout#blackjack');

       Broken dispatch chains can be continued by calling the method "continue" in Mojolicious::Controller, this
       allows for example non-blocking operations to finish before reaching the next dispatch cycle.

         my $maybe = $r->under('/maybe' => sub {
           my $c = shift;

           # Wait 3 seconds and then give visitors a 50% chance to continue
           Mojo::IOLoop->timer(3 => sub {

             # Loser
             return $c->render(text => 'No luck.') unless int rand 2;

             # Winner
             $c->continue;
           });

           return undef;
         });
         $maybe->get('/')->to('maybe#winner');

       Every destination is just a snapshot of the stash at the time the route matched, and only the "format"
       value is shared by all of them. For a little more power you can introspect the preceding and succeeding
       destinations with "match" in Mojolicious::Controller.

         # Action of the fourth dispatch cycle
         my $action = $c->match->stack->[3]{action};

   Formats
       File extensions like ".html" and ".txt" at the end of a route are automatically detected and stored in
       the stash value "format".

         # /foo      -> {controller => 'foo', action => 'bar'}
         # /foo.html -> {controller => 'foo', action => 'bar', format => 'html'}
         # /foo.txt  -> {controller => 'foo', action => 'bar', format => 'txt'}
         $r->get('/foo')->to('foo#bar');

       This for example allows multiple templates in different formats to share the same action code.
       Restrictive placeholders can also be used to limit the allowed formats.

         # /foo.txt -> undef
         # /foo.rss -> {controller => 'foo', action => 'bar', format => 'rss'}
         # /foo.xml -> {controller => 'foo', action => 'bar', format => 'xml'}
         $r->get('/foo' => [format => [qw(rss xml)]])->to('foo#bar');

       Or you can just disable format detection with a special type of restrictive placeholder, which gets
       inherited by nested routes, and then re-enable it on demand.

         # /foo      -> {controller => 'foo', action => 'bar'}
         # /foo.html -> undef
         $r->get('/foo' => [format => 0])->to('foo#bar');

         # /foo      -> {controller => 'foo', action => 'bar'}
         # /foo.html -> undef
         # /baz      -> undef
         # /baz.txt  -> {controller => 'baz', action => 'yada', format => 'txt'}
         # /baz.html -> {controller => 'baz', action => 'yada', format => 'html'}
         # /baz.xml  -> undef
         my $inactive = $r->under([format => 0]);
         $inactive->get('/foo')->to('foo#bar');
         $inactive->get('/baz' => [format => [qw(txt html)]])->to('baz#yada');

   WebSockets
       With the method "websocket" in Mojolicious::Routes::Route you can restrict access to WebSocket
       handshakes, which are normal "GET" requests with some additional information.

         # /echo (WebSocket handshake)
         $r->websocket('/echo')->to('foo#echo');

         # Controller
         package MyApp::Controller::Foo;
         use Mojo::Base 'Mojolicious::Controller';

         # Action
         sub echo {
           my $self = shift;
           $self->on(message => sub {
             my ($self, $msg) = @_;
             $self->send("echo: $msg");
           });
         }

         1;

       The connection gets established when you respond to the WebSocket handshake request with a 101 response
       status, which happens automatically if you subscribe to an event with "on" in Mojolicious::Controller or
       send a message with "send" in Mojolicious::Controller right away.

         GET /echo HTTP/1.1
         Host: mojolicio.us
         User-Agent: Mojolicious (Perl)
         Connection: Upgrade
         Upgrade: websocket
         Sec-WebSocket-Key: IDM3ODE4NDk2MjA1OTcxOQ==
         Sec-WebSocket-Version: 13

         HTTP/1.1 101 Switching Protocols
         Server: Mojolicious (Perl)
         Date: Tue, 03 Feb 2015 17:08:24 GMT
         Connection: Upgrade
         Upgrade: websocket
         Sec-WebSocket-Accept: SWsp5N2iNxPbHlcOTIw8ERvyVPY=

   Catch-all route
       Since routes match in the order in which they were defined, you can catch all requests that did not match
       in your last route with an optional wildcard placeholder.

         # * /*
         $r->any('/*whatever' => {whatever => ''} => sub {
           my $c        = shift;
           my $whatever = $c->param('whatever');
           $c->render(text => "/$whatever did not match.", status => 404);
         });

   Conditions
       Conditions such as "headers", "agent" and "host" from Mojolicious::Plugin::HeaderCondition can be applied
       to any route with the method "over" in Mojolicious::Routes::Route, and allow even more powerful route
       constructs.

         # / (Origin: http://mojolicio.us)
         $r->get('/')->over(headers => {Origin => qr/mojolicio\.us/})->to('foo#bar');

         # / (Firefox)
         $r->get('/')->over(agent => qr/Firefox/)->to('browser-test#firefox');

         # / (Internet Explorer)
         $r->get('/')->over(agent => qr/Internet Explorer/)->to('browser-test#ie');

         # http://mojolicio.us/perldoc
         $r->get('/perldoc')->over(host => 'mojolicio.us')->to('perldoc#index');

       Just be aware that conditions are too complex for the routing cache, which normally speeds up recurring
       requests, and can therefore reduce performance.

   Hooks
       Hooks operate outside the routing system and allow you to extend the framework itself by sharing code
       with all requests indiscriminately through "hook" in Mojolicious, which makes them a very powerful tool
       especially for plugins.

         # Application
         package MyApp;
         use Mojo::Base 'Mojolicious';

         sub startup {
           my $self = shift;

           # Check all requests for a "/test" prefix
           $self->hook(before_dispatch => sub {
             my $c = shift;
             $c->render(text => 'This request did not reach the router.')
               if $c->req->url->path->contains('/test');
           });

           # These will not be reached if the hook above renders a response
           my $r = $self->routes;
           $r->get('/welcome')->to('foo#welcome');
           $r->post('/bye')->to('foo#bye');
         }

         1;

       Post-processing the response to add or remove headers is a very common use.

         # Make sure static files are cached
         $app->hook(after_static => sub {
           my $c = shift;
           $c->res->headers->cache_control('max-age=3600, must-revalidate');
         });

         # Remove a default header
         $app->hook(after_dispatch => sub {
           my $c = shift;
           $c->res->headers->remove('Server');
         });

       Same for pre-processing the request.

         # Choose template variant based on request headers
         $app->hook(before_dispatch => sub {
           my $c = shift;
           return unless my $agent = $c->req->headers->user_agent;
           $c->stash(variant => 'ie') if $agent =~ /Internet Explorer/;
         });

       Or more advanced extensions to add monitoring to your application.

         # Forward exceptions to a web service
         $app->hook(after_dispatch => sub {
           my $c = shift;
           return unless my $e = $c->stash('exception');
           $c->ua->post('https://example.com/bugs' => form => {exception => $e});
         });

       You can even extend much of the core functionality.

         # Make controller object available to actions as $_
         $app->hook(around_action => sub {
           my ($next, $c, $action, $last) = @_;
           local $_ = $c;
           return $next->();
         });

         # Pass route name as argument to actions
         $app->hook(around_action => sub {
           my ($next, $c, $action, $last) = @_;
           return $c->$action($c->current_route);
         });

       For a full list of available hooks see "HOOKS" in Mojolicious.

   Introspection
       The command Mojolicious::Command::routes can be used from the command line to list all available routes
       together with name and underlying regular expressions.

         $ ./myapp.pl routes -v
         /foo/:name  ....  POST  fooname  ^/foo/([^/\.]+)  ^/?(?:\.([^/]+))?$
         /bar        ..U.  *     bar      ^/bar
           +/baz     ...W  GET   baz      ^/baz            ^/?(?:\.([^/]+))?$
         /yada       ....  *     yada     ^/yada           ^/?(?:\.([^/]+))?$

ADVANCED

       Less commonly used and more powerful features.

   Shortcuts
       You can also add your own shortcuts with "add_shortcut" in Mojolicious::Routes to make route generation
       more expressive.

         # Simple "resource" shortcut
         $r->add_shortcut(resource => sub {
           my ($r, $name) = @_;

           # Prefix for resource
           my $resource = $r->any("/$name")->to("$name#");

           # Render a list of resources
           $resource->get->to('#index')->name($name);

           # Render a form to create a new resource (submitted to "store")
           $resource->get('/create')->to('#create')->name("create_$name");

           # Store newly created resource (submitted by "create")
           $resource->post->to('#store')->name("store_$name");

           # Render a specific resource
           $resource->get('/:id')->to('#show')->name("show_$name");

           # Render a form to edit a resource (submitted to "update")
           $resource->get('/:id/edit')->to('#edit')->name("edit_$name");

           # Store updated resource (submitted by "edit")
           $resource->put('/:id')->to('#update')->name("update_$name");

           # Remove a resource
           $resource->delete('/:id')->to('#remove')->name("remove_$name");

           return $resource;
         });

         # GET /users         -> {controller => 'users', action => 'index'}
         # GET /users/create  -> {controller => 'users', action => 'create'}
         # POST /users        -> {controller => 'users', action => 'store'}
         # GET /users/23      -> {controller => 'users', action => 'show', id => 23}
         # GET /users/23/edit -> {controller => 'users', action => 'edit', id => 23}
         # PUT /users/23      -> {controller => 'users', action => 'update', id => 23}
         # DELETE /users/23   -> {controller => 'users', action => 'remove', id => 23}
         $r->resource('users');

   Rearranging routes
       Until the first request has been handled, all routes can still be moved around or even removed with
       methods like "add_child" in Mojolicious::Routes::Route and "remove" in Mojolicious::Routes::Route.

         # GET /example/show -> {controller => 'example', action => 'show'}
         my $show = $r->get('/show')->to('example#show');
         $r->any('/example')->add_child($show);

         # Nothing
         $r->get('/secrets/show')->to('secrets#show')->name('show_secrets');
         $r->find('show_secrets')->remove;

       Especially for rearranging routes created by plugins this can be very useful, to find routes by their
       name you can use "find" in Mojolicious::Routes::Route.

   Adding conditions
       You can also add your own conditions with the method "add_condition" in Mojolicious::Routes. All
       conditions are basically router plugins that run every time a new request arrives, and which need to
       return a true value for the route to match.

         # A condition that randomly allows a route to match
         $r->add_condition(
           random => sub {
             my ($route, $c, $captures, $num) = @_;

             # Loser
             return undef unless int rand $num;

             # Winner
             return 1;
           }
         );

         # /maybe (25% chance)
         $r->get('/maybe')->over(random => 4)->to('foo#bar');

   Condition plugins
       You can also package your conditions as reusable plugins.

         # Plugin
         package Mojolicious::Plugin::WerewolfCondition;
         use Mojo::Base 'Mojolicious::Plugin';

         use Astro::MoonPhase;

         sub register {
           my ($self, $app) = @_;

           # Add "werewolf" condition
           $app->routes->add_condition(werewolf => sub {
             my ($route, $c, $captures, $days) = @_;

             # Keep the werewolves out!
             return undef if abs(14 - (phase(time))[2]) > ($days / 2);

             # It's ok, no werewolf
             return 1;
           });
         }

         1;

       Now just load the plugin and you are ready to use the condition in all your applications.

         # Application
         package MyApp;
         use Mojo::Base 'Mojolicious';

         sub startup {
           my $self = shift;

           # Plugin
           $self->plugin('WerewolfCondition');

           # /hideout (keep them out for 4 days after full moon)
           $self->routes->get('/hideout')->over(werewolf => 4)
             ->to(controller => 'foo', action => 'bar');
         }

         1;

   Mount applications
       The easiest way to embed one application into another is Mojolicious::Plugin::Mount, which allows you to
       mount whole self-contained applications under a domain and/or prefix.

         use Mojolicious::Lite;

         # Whole application mounted under "/prefix"
         plugin Mount => {'/prefix' => '/home/sri/myapp.pl'};

         # Mount application with subdomain
         plugin Mount => {'test.example.com' => '/home/sri/myapp2.pl'};

         # Normal route
         get '/' => sub { shift->render(text => 'Hello World!') };

         app->start;

   Embed applications
       For a litte more power you can also embed applications by using them instead of a controller. This allows
       for example the use of the Mojolicious::Lite domain specific language in normal Mojolicious controllers.

         # Controller
         package MyApp::Controller::Bar;
         use Mojolicious::Lite;

         # /hello
         get '/hello' => sub {
           my $c    = shift;
           my $name = $c->param('name');
           $c->render(text => "Hello $name.");
         };

         1;

       With the method "detour" in Mojolicious::Routes::Route which is very similar to "to" in
       Mojolicious::Routes::Route, you can allow the route to partially match and use only the remaining path in
       the embedded application, the base path will be passed along in the "path" stash value.

         # /foo/*
         $r->any('/foo')->detour('bar#', name => 'Mojo');

       A minimal embeddable application is nothing more than a subclass of Mojo, containing a "handler" method
       accepting Mojolicious::Controller objects.

         package MyApp::Controller::Bar;
         use Mojo::Base 'Mojo';

         sub handler {
           my ($self, $c) = @_;
           $c->res->code(200);
           my $name = $c->param('name');
           $c->res->body("Hello $name.");
         }

         1;

   Application plugins
       You can even package applications as self-contained reusable plugins.

         # Plugin
         package Mojolicious::Plugin::MyEmbeddedApp;
         use Mojo::Base 'Mojolicious::Plugin';

         sub register {
           my ($self, $app) = @_;

           # Automatically add route
           $app->routes->any('/foo')->detour(app => EmbeddedApp::app());
         }

         package EmbeddedApp;
         use Mojolicious::Lite;

         get '/bar' => 'bar';

         1;
         __DATA__
         @@ bar.html.ep
         Hello World!

       The "app" stash value, which won't be inherited by nested routes, can be used for already instantiated
       applications. Now just load the plugin and you're done.

         # Application
         package MyApp;
         use Mojo::Base 'Mojolicious';

         sub startup {
           my $self = shift;

           # Plugin
           $self->plugin('MyEmbeddedApp');
         }

         1;

MORE

       You can continue with Mojolicious::Guides now or take a look at the Mojolicious wiki
       <http://github.com/kraih/mojo/wiki>, which contains a lot more documentation and examples by many
       different authors.

SUPPORT

       If you have any questions the documentation might not yet answer, don't hesitate to ask on the mailing-
       list <http://groups.google.com/group/mojolicious> or the official IRC channel "#mojo" on "irc.perl.org".

perl v5.22.1                                       2015-12-28                  Mojolicious::Guides::Routing(3pm)