Mojolicious::Lite(3)

NAME
Mojolicious::Lite - Real-time micro web framework

SYNOPSIS
  # Automatically enables "strict", "warnings", "utf8" and Perl 5.10 features
  use Mojolicious::Lite;

  # Route with placeholder
  get '/:foo' => sub {
    my $self = shift;
    my $foo  = $self->param('foo');
    $self->render(text => "Hello from $foo.");
  };

  # Start the Mojolicious command system
  app->start;

DESCRIPTION
Mojolicious::Lite is a micro real-time web framework built around Mojolicious.

TUTORIAL
A quick example driven introduction to the wonders of Mojolicious::Lite. Most of what you'll learn here also applies to normal Mojolicious applications.

  Hello World
A simple Hello World application can look like this, strict, warnings, utf8 and Perl 5.10 features are automatically enabled and a few functions imported when you use Mojolicious::Lite, turning your script into a full featured web application.

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

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

  app->start;

There is also a helper command to generate a small example application.

  $ mojo generate lite_app myapp.pl

  Commands
All the normal Mojolicious::Commands are available from the command line. Note that CGI and PSGI environments can usually be auto detected and will just work without commands.

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

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

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

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

The "app->start" call that starts the Mojolicious command system should usually be the last expression in your application and can be customized to override normal @ARGV use.

  app->start('cgi');

  Reloading
Your application will automatically reload itself if you start it with the "morbo" development web server, so you don't have to restart the server after every change.

  $ morbo myapp.pl
  Server 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
Routes are basically just fancy paths that can contain different kinds of placeholders and usually lead to an action. The first argument passed to all actions (the invocant $self) is a Mojolicious::Controller object containing both the HTTP request and response.

  use Mojolicious::Lite;

  # Route leading to an action
  get '/foo' => sub {
    my $self = shift;
    $self->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
All GET and POST parameters sent with the request are accessible via "param" in Mojolicious::Controller.

  use Mojolicious::Lite;

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

  app->start;

  Stash and templates
The "stash" in Mojolicious::Controller is used to pass data to templates, which can be inlined in the "DATA" section.

  use Mojolicious::Lite;

  # Route leading to an action that renders a template
  get '/bar' => sub {
    my $self = shift;
    $self->stash(one => 23);
    $self->render('baz', two => 24);
  };

  app->start;
  __DATA__

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

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

  HTTP
"req" in Mojolicious::Controller and "res" in Mojolicious::Controller give you full access to all HTTP features and information.

  use Mojolicious::Lite;

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

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

  app->start;

  Route names
All routes can have a name associated with them, this allows automatic template detection and back referencing with "url_for" in Mojolicious::Controller as well as many helpers like "link_to" in Mojolicious::Plugin::TagHelpers. Nameless routes get an automatically generated one assigned that is simply equal to the route itself without non-word characters.

  use Mojolicious::Lite;

  # Render the template "index.html.ep"
  get '/' => sub {
    my $self = shift;
    $self->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!

  Layouts
Templates can have layouts too, you just select one with the helper "layout" in Mojolicious::Plugin::DefaultHelpers and place the result of the current template with the helper "content" in Mojolicious::Plugin::DefaultHelpers.

  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
Template blocks can be used like normal Perl functions and are always delimited by the "begin" and "end" keywords.

  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://mojolicio.us', 'Mojolicious')
      %= $link->('http://catalystframework.org', 'Catalyst')
    </body>
  </html>

  Captured content
The helper "content_for" in Mojolicious::Plugin::DefaultHelpers can be used to pass around blocks of captured content.

  use Mojolicious::Lite;

  get '/captured';

  app->start;
  __DATA__

  @@ captured.html.ep
  % layout 'blue', title => 'Green';
  % content_for header => begin
    <meta http-equiv="Pragma" content="no-cache">
  % end
  Hello World!
  % content_for header => begin
    <meta http-equiv="Expires" content="-1">
  % end

  @@ layouts/blue.html.ep
  <!DOCTYPE html>
  <html>
    <head>
      <title><%= title %></title>
      %= content_for 'header'
    </head>
    <body><%= content %></body>
  </html>

  Helpers
You can also extend Mojolicious with your own helpers, a list of all built-in ones can be found in Mojolicious::Plugin::DefaultHelpers and Mojolicious::Plugin::TagHelpers.

  use Mojolicious::Lite;

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

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

  app->start;
  __DATA__

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

  Placeholders
Route placeholders allow capturing parts of a request path until a "/" or "." separator occurs, results are accessible via "stash" in Mojolicious::Controller and "param" in Mojolicious::Controller.

  use Mojolicious::Lite;

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

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

  app->start;

  Relaxed Placeholders
Relaxed placeholders allow matching of everything until a "/" occurs.

  use Mojolicious::Lite;

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

  app->start;
  __DATA__

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

  Wildcard placeholders
Wildcard placeholders allow matching absolutely everything, including "/" and ".".

  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
Routes can be restricted to specific request methods with different keywords.

  use Mojolicious::Lite;

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

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

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

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

  app->start;

  Optional placeholders
All placeholders require a value, but by assigning them default values you can make capturing optional.

  use Mojolicious::Lite;

  # /hello
  # /hello/Sara
  get '/hello/:name' => {name => 'Sebastian'} => sub {
    my $self = shift;
    $self->render('groovy', format => 'txt');
  };

  app->start;
  __DATA__

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

  Restrictive placeholders
The easiest way to make placeholders more restrictive are alternatives, you just make a list of possible values.

  use Mojolicious::Lite;

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

  app->start;

All placeholders get compiled to a regular expression internally, this process can also be easily customized.

  use Mojolicious::Lite;

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

  app->start;

Just make sure not to use "^" and "$" or capturing groups "(...)", because placeholders become part of a larger regular expression internally, "(?:...)" is fine though.

  Under
Authentication and code shared between multiple routes can be realized easily with bridge routes generated by the "under" statement. All following routes are only evaluated if the callback returned a true value.

  use Mojolicious::Lite;

  # Authenticate based on name parameter
  under sub {
    my $self = shift;

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

    # Not authenticated
    $self->render('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 "under".

  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, which allows nesting of multiple "under" statements.

  use Mojolicious::Lite;

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

  # Admin section
  group {

    # Local logic shared only by routes in this group
    under '/admin' => sub {
      my $self = shift;
      return 1 if $self->req->headers->header('X-Awesome');
      $self->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
Formats can be automatically detected by looking at file extensions.

  use Mojolicious::Lite;

  # /detection.html
  # /detection.txt
  get '/detection' => sub {
    my $self = shift;
    $self->render('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.

Restrictive placeholders can also be used.

  use Mojolicious::Lite;

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

  app->start;

Or you can just disable format detection.

  use Mojolicious::Lite;

  # /hello
  get '/hello' => [format => 0] => {text => 'No format detection.'};

  # Disable detection and allow the following routes selective re-enabling
  under [format => 0];

  # /foo
  get '/foo' => {text => 'No format detection again.'};

  # /bar.txt
  get '/bar' => [format => 'txt'] => {text => ' Just one format.'};

  app->start;

  Content negotiation
For resources with different representations and that require truly "RESTful" content negotiation you can also use "respond_to" in Mojolicious::Controller.

  use Mojolicious::Lite;

  # /hello (Accept: application/json)
  # /hello (Accept: application/xml)
  # /hello.json
  # /hello.xml
  # /hello?format=json
  # /hello?format=xml
  get '/hello' => sub {
    my $self = shift;
    $self->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
Similar to templates, but with only a single file extension and optional Base64 encoding, static files can be inlined in the "DATA" section and are served automatically.

  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.

  External templates
External templates will be searched by the renderer in a "templates" directory if it exists.

  use Mojolicious::Lite;

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

  app->start;

  Conditions
Conditions such as "agent" and "host" from Mojolicious::Plugin::HeaderCondition allow even more powerful route constructs.

  use Mojolicious::Lite;

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

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

  # http://mojolicio.us/bar
  get '/bar' => (host => 'mojolicio.us') => sub {
    my $self = shift;
    $self->render(text => 'Hello Mojolicious.');
  };

  app->start;

  Sessions
Signed cookie based sessions just work out of the box as soon as you start using them through the helper "session" in Mojolicious::Plugin::DefaultHelpers, just be aware that all session data gets serialized with Mojo::JSON.

  use Mojolicious::Lite;

  # Access session data in action and template
  get '/counter' => sub {
    my $self = shift;
    $self->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 secure.

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

  File uploads
All files uploaded via "multipart/form-data" request are automatically available as Mojo::Upload objects. And you don't have to worry about memory usage, because all files above "250KB" will be automatically streamed into a temporary file.

  use Mojolicious::Lite;

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

  # Multipart upload handler
  post '/upload' => sub {
    my $self = shift;

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

    # Process uploaded file
    return $self->redirect_to('form')
      unless my $example = $self->param('example');
    my $size = $example->size;
    my $name = $example->filename;
    $self->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 "10MB" by default, which you can tweak with the MOJO_MAX_MESSAGE_SIZE environment variable.

  # Increase limit to 1GB
  $ENV{MOJO_MAX_MESSAGE_SIZE} = 1073741824;

  User agent
With Mojo::UserAgent, which is available through the helper "ua" in Mojolicious::Plugin::DefaultHelpers, there's a full featured HTTP and WebSocket user agent built right in. Especially in combination with Mojo::JSON and Mojo::DOM this can be a very powerful tool.

  use Mojolicious::Lite;

  # Blocking
  get '/headers' => sub {
    my $self = shift;
    my $url  = $self->param('url') || 'http://mojolicio.us';
    my $dom  = $self->ua->get($url)->res->dom;
    $self->render(json => [$dom->find('h1, h2, h3')->text->each]);
  };

  # Non-blocking
  get '/title' => sub {
    my $self = shift;
    $self->ua->get('mojolicio.us' => sub {
      my ($ua, $tx) = @_;
      $self->render(data => $tx->res->dom->at('title')->text);
    });
  };

  # Parallel non-blocking
  get '/titles' => sub {
    my $self = shift;
    my $delay = Mojo::IOLoop->delay(sub {
      my ($delay, @titles) = @_;
      $self->render(json => \@titles);
    });
    for my $url ('http://mojolicio.us', 'https://metacpan.org') {
      my $end = $delay->begin(0);
      $self->ua->get($url => sub {
        my ($ua, $tx) = @_;
        $end->($tx->res->dom->html->head->title->text);
      });
    }
  };

  app->start;

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

  WebSockets
WebSocket applications have never been this simple before. Just receive messages by subscribing to events such as "json" in Mojo::Transaction::WebSocket with "on" in Mojolicious::Controller and return them with "send" in Mojolicious::Controller.

  use Mojolicious::Lite;

  websocket '/echo' => sub {
    my $self = shift;
    $self->on(json => sub {
      my ($self, $hash) = @_;
      $hash->{msg} = "echo: $hash->{msg}";
      $self->send({json => $hash});
    });
  };

  get '/' => 'index';

  app->start;
  __DATA__

  @@ index.html.ep
  <!DOCTYPE html>
  <html>
    <head>
      <title>Echo</title>
      %= javascript begin
        var 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 X Mojolicious!'}));
        };
      % end
    </head>
  </html>

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

  Mode
You can use the Mojo::Log object from "log" in Mojo to portably collect debug messages and automatically disable them later in a production setup by changing the Mojolicious operating mode, which can also be retrieved from the attribute "mode" in Mojolicious.

  use Mojolicious::Lite;

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

  get '/' => sub {
    my $self = shift;
    $self->app->log->debug('Rendering mode specific message.');
    $self->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 "debug" to "info".

  $ ./myapp.pl daemon -m production

All messages will be written to "STDERR" or a "log/$mode.log" file if a "log" directory exists.

  $ mkdir log

Mode changes also affect a few other aspects of the framework, such as mode specific "exception" and "not_found" templates.

  Testing
Testing your application is as easy as creating a "t" directory and filling it with normal Perl unit tests, which can be a lot of fun thanks to Test::Mojo.

  use Test::More;
  use Test::Mojo;

  use FindBin;
  require "$FindBin::Bin/../myapp.pl";

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

  done_testing();

Run all unit tests with the "test" command.

  $ ./myapp.pl test
  $ ./myapp.pl test -v

  More
You can continue with Mojolicious::Guides now, and don't forget to have fun!

FUNCTIONS
Mojolicious::Lite implements the following functions.

  any
  my $route = any '/:foo' => sub {...};
  my $route = any [qw(GET POST)] => '/:foo' => sub {...};

Generate route with "any" in Mojolicious::Routes::Route, matching any of the listed HTTP request methods or all. See also the tutorial above for more argument variations.

  app
  my $app = app;

The Mojolicious::Lite application.

  del
  my $route = del '/:foo' => sub {...};

Generate route with "delete" in Mojolicious::Routes::Route, matching only DELETE requests. See also the tutorial above for more argument variations.

  get
  my $route = get '/:foo' => sub {...};

Generate route with "get" in Mojolicious::Routes::Route, matching only GET requests. See also the tutorial above for more argument variations.

  group
  group {...};

Start a new route group.

  helper
  helper foo => sub {...};

Add a new helper with "helper" in Mojolicious.

  hook
  hook after_dispatch => sub {...};

Share code with "hook" in Mojolicious.

  options
  my $route = options '/:foo' => sub {...};

Generate route with "options" in Mojolicious::Routes::Route, matching only OPTIONS requests. See also the tutorial above for more argument variations.

  patch
  my $route = patch '/:foo' => sub {...};

Generate route with "patch" in Mojolicious::Routes::Route, matching only PATCH requests. See also the tutorial above for more argument variations.

  plugin
  plugin SomePlugin => {foo => 23};

Load a plugin with "plugin" in Mojolicious.

  post
  my $route = post '/:foo' => sub {...};

Generate route with "post" in Mojolicious::Routes::Route, matching only POST requests. See also the tutorial above for more argument variations.

  put
  my $route = put '/:foo' => sub {...};

Generate route with "put" in Mojolicious::Routes::Route, matching only PUT requests. See also the tutorial above for more argument variations.

  under
  my $bridge = under sub {...};
  my $bridge = under '/:foo';

Generate bridge route with "under" in Mojolicious::Routes::Route, to which all following routes are automatically appended. See also the tutorial above for more argument variations.

  websocket
  my $route = websocket '/:foo' => sub {...};

Generate route with "websocket" in Mojolicious::Routes::Route, matching only WebSocket handshakes. See also the tutorial above for more argument variations.

ATTRIBUTES
Mojolicious::Lite inherits all attributes from Mojolicious.

METHODS
Mojolicious::Lite inherits all methods from Mojolicious.

SEE ALSO
Mojolicious, Mojolicious::Guides, <http://mojolicio.us>.