Provided by: libmojolicious-perl_7.59+dfsg-1ubuntu1_all 
NAME
Mojolicious::Guides::Routing - Routing requests
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 => 'Daniel');
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 => 'Isabell');
/user/show/3 -> $c->render(text => 'Sara');
/user/show/4 -> $c->render(text => 'Stefan');
/user/show/5 -> $c->render(text => 'Fynn');
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: mojolicious.org
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.
# 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. Routes are usually configured in the "startup" method of the
application class, but the router can be accessed from everywhere (even at runtime).
# Controller
package MyApp::Controller::Foo;
use Mojo::Base 'Mojolicious::Controller';
# Action
sub welcome {
my $self = shift;
# Render response
$self->render(text => 'Hello there.');
}
1;
All routes match in the same order in which they were defined, and matching stops as soon
as a suitable route has been found. So you can improve the routing performance by
declaring your most frequently accessed routes first. A routing cache will also be used
automatically to handle sudden traffic spikes more gracefully.
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(['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');
With a few common prefixes you can also greatly improve the routing performance of
applications with many routes, because children are only tried if the prefix matched
first.
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 which 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.
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'}
$r->get('/:name' => [name => ['bender', 'leela']])->to('foo#bar');
You can also adjust the regular expressions behind placeholders directly, just make sure
not to use "^" and "$" or capturing groups "(...)", because placeholders become part of a
larger regular expression internally, non-capturing groups "(?:...)" are 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.
Introspection
The command Mojolicious::Command::routes can be used from the command line to list all
available routes together with names 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/?(?:\.([^/]+))?$
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.", status => 401);
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 => ['rss', 'xml']])->to('foo#bar');
A "format" value can also be passed to "url_for" in Mojolicious::Controller.
# /foo/bar.txt -> {controller => 'foo', action => 'bar', format => 'txt'}
$r->get('/foo/:action')->to('foo#')->name('baz');
# Generate URL "/foo/bar.txt" for route "baz"
my $url = $c->url_for('baz', action => 'bar', format => 'txt');
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 => ['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: mojolicious.org
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://perl.org)
$r->get('/')->over(headers => {Origin => qr/perl\.org/})->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://mojolicious.org/perldoc
$r->get('/perldoc')->over(host => 'mojolicious.org')->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.
ADVANCED
Less commonly used and more powerful features.
Shortcuts
To make route generation more expressive, you can also add your own shortcuts with
"add_shortcut" in Mojolicious::Routes.
# 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
From application startup until the first request has arrived, 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.
# GET /example/test -> {controller => 'example', action => 'test'}
$r->get('/something/else')->to('something#else')->name('test');
my $test = $r->find('test');
$test->pattern->parse('/example/test');
$test->pattern->defaults({controller => 'example', action => 'test'});
Even the route pattern and destination can still be changed with "parse" in
Mojolicious::Routes::Pattern and "defaults" in Mojolicious::Routes::Pattern.
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 if int rand $num;
# Winner
return 1;
});
# /maybe (25% chance)
$r->get('/maybe')->over(random => 4)->to('foo#bar');
Use whatever request information you need.
# A condition to check query parameters (useful for mock web services)
$r->add_condition(query => sub {
my ($route, $c, $captures, $hash) = @_;
for my $key (keys %$hash) {
my $param = $c->req->url->query->param($key);
return undef unless defined $param && $param eq $hash->{$key};
}
return 1;
});
# /hello?to=world&test=1
$r->get('/hello')->over(query => {test => 1, to => 'world'})->to('foo#bar');
Condition plugins
You can also package your conditions as reusable plugins.
# Plugin
package Mojolicious::Plugin::WerewolfCondition;
use Mojo::Base 'Mojolicious::Plugin';
use Astro::MoonPhase;
sub register {
my ($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 little 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 $name.");
}
1;
The host application will only share very little information with the embedded application
through the stash. So you cannot currently use route placeholders in routes leading to
embedded applications, since that would cause problems with "url_for" in
Mojolicious::Controller.
Application plugins
You can even package applications as self-contained reusable plugins.
# Plugin
package Mojolicious::Plugin::MyEmbeddedApp;
use Mojo::Base 'Mojolicious::Plugin';
sub register {
my ($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" (chat now!
<https://chat.mibbit.com/?channel=%23mojo&server=irc.perl.org>).