Hello World

  #!/usr/bin/env perl
  use Mojolicious::Lite -signatures;

  get '/' => sub ($c) {
    $c->render(text => 'Hello World!');
  };

  app->start;

With Mojolicious::Command::Author::generate::lite_app there is also a helper command to generate a small example application.

  $ mojo generate lite-app myapp.pl

Commands

  $ ./myapp.pl daemon
  Web application available at http://127.0.0.1:3000

  $ ./myapp.pl daemon -l http://*:8080
  Web application available at http://127.0.0.1:8080

  $ ./myapp.pl cgi
  ...CGI output...

  $ ./myapp.pl get /
  Hello World!

  $ ./myapp.pl
  ...List of available commands (or automatically detected environment)...

A call to "start" in Mojolicious ("app->start"), which starts the command system, should be the last expression in your application, because its return value can be significant.

  # Use @ARGV to pick a command
  app->start;

  # Start the "daemon" command
  app->start('daemon', '-l', 'http://*:8080');

Reloading

  $ morbo ./myapp.pl
  Web application available at http://127.0.0.1:3000

For more information about how to deploy your application see also "DEPLOYMENT" in Mojolicious::Guides::Cookbook.

Routes

  use Mojolicious::Lite -signatures;

  # Route leading to an action that renders some text
  get '/foo' => sub ($c) {
    $c->render(text => 'Hello World!');
  };

  app->start;

Response content is often generated by actions with "render" in Mojolicious::Controller, but more about that later.

GET/POST parameters

  use Mojolicious::Lite -signatures;

  # /foo?user=sri
  get '/foo' => sub ($c) {
    my $user = $c->param('user');
    $c->render(text => "Hello $user.");
  };

  app->start;

Stash and templates

  use Mojolicious::Lite -signatures;

  # Route leading to an action that renders a template
  get '/foo' => sub ($c) {
    $c->stash(one => 23);
    $c->render(template => 'magic', two => 24);
  };

  app->start;
  __DATA__

  @@ magic.html.ep
  The magic numbers are <%= $one %> and <%= $two %>.

For more information about templates see also "Embedded Perl" in Mojolicious::Guides::Rendering.

HTTP

  use Mojolicious::Lite -signatures;

  # Access request information
  get '/agent' => sub ($c) {
    my $host = $c->req->url->to_abs->host;
    my $ua   = $c->req->headers->user_agent;
    $c->render(text => "Request by $ua reached $host.");
  };

  # Echo the request body and send custom header with response
  post '/echo' => sub ($c) {
    $c->res->headers->header('X-Bender' => 'Bite my shiny metal ass!');
    $c->render(data => $c->req->body);
  };

  app->start;

You can test the more advanced examples right from the command line with Mojolicious::Command::get.

  $ ./myapp.pl get -v -M POST -c 'test' /echo

JSON

  use Mojolicious::Lite -signatures;

  # Modify the received JSON document and return it
  put '/reverse' => sub ($c) {
    my $hash = $c->req->json;
    $hash->{message} = reverse $hash->{message};
    $c->render(json => $hash);
  };

  app->start;

You can send JSON documents from the command line with Mojolicious::Command::get.

  $ ./myapp.pl get -M PUT -c '{"message":"Hello Mojo!"}' /reverse

Built-in "exception" and "not_found" pages

  use Mojolicious::Lite -signatures;

  # Not found (404)
  get '/missing' => sub ($c) {
    $c->render(template => 'does_not_exist');
  };

  # Exception (500)
  get '/dies' => sub { die 'Intentional error' };

  app->start;

You can even use CSS selectors with Mojolicious::Command::get to extract only the information you're actually interested in.

  $ ./myapp.pl get /dies '#error'

And don't worry about revealing too much information on these pages, they are only available during development, and will be replaced automatically with pages that don't reveal any sensitive information in a production environment.

Route names

  use Mojolicious::Lite -signatures;

  # Render the template "index.html.ep"
  get '/' => sub ($c) {
    $c->render;
  } => 'index';

  # Render the template "hello.html.ep"
  get '/hello';

  app->start;
  __DATA__

  @@ index.html.ep
  <%= link_to Hello  => 'hello' %>.
  <%= link_to Reload => 'index' %>.

  @@ hello.html.ep
  Hello World!

Nameless routes get an automatically generated one assigned that is simply equal to the route itself without non-word characters.

Layouts

  use Mojolicious::Lite;

  get '/with_layout';

  app->start;
  __DATA__

  @@ with_layout.html.ep
  % title 'Green';
  % layout 'green';
  Hello World!

  @@ layouts/green.html.ep
  <!DOCTYPE html>
  <html>
    <head><title><%= title %></title></head>
    <body><%= content %></body>
  </html>

The stash or helpers like "title" in Mojolicious::Plugin::DefaultHelpers can be used to pass additional data to the layout.

Blocks

  use Mojolicious::Lite;

  get '/with_block' => 'block';

  app->start;
  __DATA__

  @@ block.html.ep
  % my $link = begin
    % my ($url, $name) = @_;
    Try <%= link_to $url => begin %><%= $name %><% end %>.
  % end
  <!DOCTYPE html>
  <html>
    <head><title>Sebastians frameworks</title></head>
    <body>
      %= $link->('http://mojolicious.org', 'Mojolicious')
      %= $link->('http://mojojs.org', 'mojo.js')
    </body>
  </html>

Helpers

  use Mojolicious::Lite -signatures;

  # A helper to identify visitors
  helper whois => sub ($c) {
    my $agent = $c->req->headers->user_agent || 'Anonymous';
    my $ip    = $c->tx->remote_address;
    return "$agent ($ip)";
  };

  # Use helper in action and template
  get '/secret' => sub ($c) {
    my $user = $c->whois;
    $c->app->log->debug("Request from $user");
  };

  app->start;
  __DATA__

  @@ secret.html.ep
  We know who you are <%= whois %>.

A list of all built-in ones can be found in Mojolicious::Plugin::DefaultHelpers and Mojolicious::Plugin::TagHelpers.

Plugins

  use Mojolicious::Lite;

  plugin Config => {file => '/etc/myapp.conf', default => {foo => 'bar'}};

  # Return configured foo value, or default if no configuration file
  get '/foo' => sub ($c) {
    my $foo = $c->app->config('foo');
    $c->render(json => {foo => $foo});
  };

  app->start;

Mojolicious::Plugin::Config is a built-in plugin which can populate "config" in Mojolicious using a config file. Plugins can also set up routes, hooks, handlers, or even load other plugins. A list of built-in plugins can be found at "PLUGINS" in Mojolicious::Plugins, and many more are available from CPAN <https://metacpan.org/search?q=Mojolicious+Plugin>.

Placeholders

  use Mojolicious::Lite -signatures;

  # /foo/test
  # /foo/test123
  get '/foo/:bar' => sub ($c) {
    my $bar = $c->stash('bar');
    $c->render(text => "Our :bar placeholder matched $bar");
  };

  # /testsomething/foo
  # /test123something/foo
  get '/<:bar>something/foo' => sub ($c) {
    my $bar = $c->param('bar');
    $c->render(text => "Our :bar placeholder matched $bar");
  };

  app->start;

To separate them from the surrounding text, you can surround your placeholders with "<" and ">", which also makes the colon prefix optional.

Relaxed Placeholders

  use Mojolicious::Lite;

  # /hello/test
  # /hello/test.html
  get '/hello/#you' => 'groovy';

  app->start;
  __DATA__

  @@ groovy.html.ep
  Your name is <%= $you %>.

Wildcard placeholders

  use Mojolicious::Lite;

  # /hello/test
  # /hello/test123
  # /hello/test.123/test/123
  get '/hello/*you' => 'groovy';

  app->start;
  __DATA__

  @@ groovy.html.ep
  Your name is <%= $you %>.

HTTP methods

  use Mojolicious::Lite -signatures;

  # GET /hello
  get '/hello' => sub ($c) {
    $c->render(text => 'Hello World!');
  };

  # PUT /hello
  put '/hello' => sub ($c) {
    my $size = length $c->req->body;
    $c->render(text => "You uploaded $size bytes to /hello.");
  };

  # GET|POST|PATCH /bye
  any ['GET', 'POST', 'PATCH'] => '/bye' => sub ($c) {
    $c->render(text => 'Bye World!');
  };

  # * /whatever
  any '/whatever' => sub ($c) {
    my $method = $c->req->method;
    $c->render(text => "You called /whatever with $method.");
  };

  app->start;

Optional placeholders

  use Mojolicious::Lite -signatures;

  # /hello
  # /hello/Sara
  get '/hello/:name' => {name => 'Sebastian', day => 'Monday'} => sub ($c) {
    $c->render(template => 'groovy', format => 'txt');
  };

  app->start;
  __DATA__

  @@ groovy.txt.ep
  My name is <%= $name %> and it is <%= $day %>.

Default values that don't belong to a placeholder simply get merged into the stash all the time.

Restrictive placeholders

  use Mojolicious::Lite -signatures;

  # /test
  # /123
  any '/:foo' => [foo => ['test', '123']] => sub ($c) {
    my $foo = $c->param('foo');
    $c->render(text => "Our :foo placeholder matched $foo");
  };

  app->start;

All placeholders get compiled to a regular expression internally, this process can also be customized. Just make sure not to use "^" and "$", or capturing groups "(...)", non-capturing groups "(?:...)" are fine though.

  use Mojolicious::Lite -signatures;

  # /1
  # /123
  any '/:bar' => [bar => qr/\d+/] => sub ($c) {
    my $bar = $c->param('bar');
    $c->render(text => "Our :bar placeholder matched $bar");
  };

  app->start;

You can take a closer look at all the generated regular expressions with the command Mojolicious::Command::routes.

  $ ./myapp.pl routes -v

Under

  use Mojolicious::Lite -signatures;

  # Authenticate based on name parameter
  under sub ($c) {

    # Authenticated
    my $name = $c->param('name') || '';
    return 1 if $name eq 'Bender';

    # Not authenticated
    $c->render(template => 'denied');
    return undef;
  };

  # Only reached when authenticated
  get '/' => 'index';

  app->start;
  __DATA__

  @@ denied.html.ep
  You are not Bender, permission denied.

  @@ index.html.ep
  Hi Bender.

Prefixing multiple routes is another good use for it.

  use Mojolicious::Lite;

  # /foo
  under '/foo';

  # /foo/bar
  get '/bar' => {text => 'foo bar'};

  # /foo/baz
  get '/baz' => {text => 'foo baz'};

  # / (reset)
  under '/' => {msg => 'whatever'};

  # /bar
  get '/bar' => {inline => '<%= $msg %> works'};

  app->start;

You can also group related routes with "group" in Mojolicious::Lite, which allows nesting of routes generated with "under" in Mojolicious::Lite.

  use Mojolicious::Lite -signatures;

  # Global logic shared by all routes
  under sub ($c) {
    return 1 if $c->req->headers->header('X-Bender');
    $c->render(text => "You're not Bender.");
    return undef;
  };

  # Admin section
  group {

    # Local logic shared only by routes in this group
    under '/admin' => sub ($c) {
      return 1 if $c->req->headers->header('X-Awesome');
      $c->render(text => "You're not awesome enough.");
      return undef;
    };

    # GET /admin/dashboard
    get '/dashboard' => {text => 'Nothing to see here yet.'};
  };

  # GET /welcome
  get '/welcome' => {text => 'Hi Bender.'};

  app->start;

Formats

  use Mojolicious::Lite -signatures;

  # /detection.html
  # /detection.txt
  get '/detection' => [format => ['html', 'txt']] => sub ($c) {
    $c->render(template => 'detected');
  };

  app->start;
  __DATA__

  @@ detected.html.ep
  <!DOCTYPE html>
  <html>
    <head><title>Detected</title></head>
    <body>HTML was detected.</body>
  </html>

  @@ detected.txt.ep
  TXT was detected.

And just like with placeholders you can use a default value to make the format optional.

  use Mojolicious::Lite -signatures;

  # /hello
  # /hello.json
  # /hello.txt
  get '/hello' => [format => ['json', 'txt']] => {format => 'txt'} => sub ($c) {
    return $c->render(json => {hello => 'world'}) if $c->stash('format') eq 'json';
    $c->render(text => 'hello world');
  };

  app->start;

The default format is "html" and the renderer will fall back to when necessary.

Content negotiation

  use Mojolicious::Lite -signatures;

  # /hello (Accept: application/json)
  # /hello (Accept: application/xml)
  # /hello.json
  # /hello.xml
  # /hello?_format=json
  # /hello?_format=xml
  get '/hello' => [format => ['json', 'xml']] => {format => undef} => sub ($c) {
    $c->respond_to(
      json => {json => {hello => 'world'}},
      xml  => {text => '<hello>world</hello>'},
      any  => {data => '', status => 204}
    );
  };

  app->start;

MIME type mappings can be extended or changed easily with "types" in Mojolicious.

  app->types->type(rdf => 'application/rdf+xml');

Static files

  use Mojolicious::Lite;

  app->start;
  __DATA__

  @@ something.js
  alert('hello!');

  @@ test.txt (base64)
  dGVzdCAxMjMKbGFsYWxh

External static files are not limited to a single file extension and will be served automatically from a "public" directory if it exists.

  $ mkdir public
  $ mv something.js public/something.js
  $ mv mojolicious.tar.gz public/mojolicious.tar.gz

Both have a higher precedence than routes for "GET" and "HEAD" requests. Content negotiation with "Range", "If-None-Match" and "If-Modified-Since" headers is supported as well and can be tested very easily with Mojolicious::Command::get.

  $ ./myapp.pl get /something.js -v -H 'Range: bytes=2-4'

External templates

  $ mkdir -p templates/foo
  $ echo 'Hello World!' > templates/foo/bar.html.ep

They have a higher precedence than templates in the "DATA" section.

  use Mojolicious::Lite -signatures;

  # Render template "templates/foo/bar.html.ep"
  any '/external' => sub ($c) {
    $c->render(template => 'foo/bar');
  };

  app->start;

Home

  $ mkdir cache
  $ echo 'Hello World!' > cache/hello.txt

There are many useful methods Mojo::Home inherits from Mojo::File, like "child" in Mojo::File and "slurp" in Mojo::File, that will help you keep your application portable across many different operating systems.

  use Mojolicious::Lite -signatures;

  # Load message into memory
  my $hello = app->home->child('cache', 'hello.txt')->slurp;

  # Display message
  get '/' => sub ($c) {
    $c->render(text => $hello);
  };

You can also introspect your application from the command line with Mojolicious::Command::eval.

  $ ./myapp.pl eval -v 'app->home'

Conditions

  use Mojolicious::Lite -signatures;

  # Firefox
  get '/foo' => (agent => qr/Firefox/) => sub ($c) {
    $c->render(text => 'Congratulations, you are using a cool browser.');
  };

  # Internet Explorer
  get '/foo' => (agent => qr/Internet Explorer/) => sub ($c) {
    $c->render(text => 'Dude, you really need to upgrade to Firefox.');
  };

  # http://mojolicious.org/bar
  get '/bar' => (host => 'mojolicious.org') => sub ($c) {
    $c->render(text => 'Hello Mojolicious.');
  };

  app->start;

Sessions

  use Mojolicious::Lite -signatures;

  # Access session data in action and template
  get '/counter' => sub ($c) {
    $c->session->{counter}++;
  };

  app->start;
  __DATA__

  @@ counter.html.ep
  Counter: <%= session 'counter' %>

Note that you should use custom "secrets" in Mojolicious to make signed cookies really tamper resistant.

  app->secrets(['My secret passphrase here']);

File uploads

  use Mojolicious::Lite -signatures;

  # Upload form in DATA section
  get '/' => 'form';

  # Multipart upload handler
  post '/upload' => sub ($c) {

    # Check file size
    return $c->render(text => 'File is too big.', status => 200) if $c->req->is_limit_exceeded;

    # Process uploaded file
    return $c->redirect_to('form') unless my $example = $c->param('example');
    my $size = $example->size;
    my $name = $example->filename;
    $c->render(text => "Thanks for uploading $size byte file $name.");
  };

  app->start;
  __DATA__

  @@ form.html.ep
  <!DOCTYPE html>
  <html>
    <head><title>Upload</title></head>
    <body>
      %= form_for upload => (enctype => 'multipart/form-data') => begin
        %= file_field 'example'
        %= submit_button 'Upload'
      % end
    </body>
  </html>

To protect you from excessively large files there is also a limit of 16MiB by default, which you can tweak with the attribute "max_request_size" in Mojolicious.

  # Increase limit to 1GiB
  app->max_request_size(1073741824);

User agent

  use Mojolicious::Lite -signatures;

  # Blocking
  get '/headers' => sub ($c) {
    my $url = $c->param('url') || 'https://mojolicious.org';
    my $dom = $c->ua->get($url)->result->dom;
    $c->render(json => $dom->find('h1, h2, h3')->map('text')->to_array);
  };

  # Non-blocking
  get '/title' => sub ($c) {
    $c->ua->get('mojolicious.org' => sub ($ua, $tx) {
      $c->render(data => $tx->result->dom->at('title')->text);
    });
  };

  # Concurrent non-blocking
  get '/titles' => sub ($c) {
    my $mojo = $c->ua->get_p('https://mojolicious.org');
    my $cpan = $c->ua->get_p('https://metacpan.org');
    Mojo::Promise->all($mojo, $cpan)->then(sub ($mojo, $cpan) {
      $c->render(json => {
        mojo => $mojo->[0]->result->dom->at('title')->text,
        cpan => $cpan->[0]->result->dom->at('title')->text
      });
    })->wait;
  };

  app->start;

For more information about the user agent see also "USER AGENT" in Mojolicious::Guides::Cookbook.

WebSockets

  use Mojolicious::Lite -signatures;

  websocket '/echo' => sub ($c) {
    $c->on(json => sub ($c, $hash) {
      $hash->{msg} = "echo: $hash->{msg}";
      $c->send({json => $hash});
    });
  };

  get '/' => 'index';

  app->start;
  __DATA__

  @@ index.html.ep
  <!DOCTYPE html>
  <html>
    <head>
      <title>Echo</title>
      <script>
        const ws = new WebSocket('<%= url_for('echo')->to_abs %>');
        ws.onmessage = function (event) {
          document.body.innerHTML += JSON.parse(event.data).msg;
        };
        ws.onopen = function (event) {
          ws.send(JSON.stringify({msg: 'I ♥ Mojolicious!'}));
        };
      </script>
    </head>
  </html>

For more information about real-time web features see also "REAL-TIME WEB" in Mojolicious::Guides::Cookbook.

Mode

  use Mojolicious::Lite -signatures;

  # Prepare mode specific message during startup
  my $msg = app->mode eq 'development' ? 'Development!' : 'Something else!';

  get '/' => sub ($c) {
    $c->app->log->debug('Rendering mode specific message');
    $c->render(text => $msg);
  };

  app->log->debug('Starting application');
  app->start;

The default operating mode will usually be "development" and can be changed with command line options or the "MOJO_MODE" and "PLACK_ENV" environment variables. A mode other than "development" will raise the log level from "trace" to "info". All messages will be written to "STDERR" by default.

  $ ./myapp.pl daemon -m production

Mode changes also affect a few other aspects of the framework, such as the built-in "exception" and "not_found" pages. Once you switch modes from "development" to "production", no sensitive information will be revealed on those pages anymore.

Testing

  use Test::More;
  use Mojo::File qw(curfile);
  use Test::Mojo;

  # Portably point to "../myapp.pl"
  my $script = curfile->dirname->sibling('myapp.pl');

  my $t = Test::Mojo->new($script);
  $t->get_ok('/')->status_is(200)->content_like(qr/Funky/);

  done_testing();

Just run your tests with prove.

  $ prove -l -v
  $ prove -l -v t/basic.t