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

Routes allow default values to make placeholders 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 a custom "secret" in Mojolicious to make signed cookies really secure.

app->secret('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 ♥ 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 $route = under sub {...};
my $route = 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.