1Mojolicious::Guides::TuUtsoerriaClo(n3t)ributed Perl DocMuomjeonltiactiioouns::Guides::Tutorial(3)
2
6 Mojolicious::Guides::Tutorial - Get started with Mojolicious
7
9 A quick example-driven introduction to the wonders of
10 Mojolicious::Lite. Almost everything you'll learn here also applies to
11 full Mojolicious applications.
12 This is only the first of the Mojolicious::Guides. Other guides delve
14 deeper into topics like growing a Mojolicious::Lite prototype into a
15 well-structured Mojolicious application, routing, rendering and more.
16 It is highly encouraged that readers continue on to the remaining
17 guides after reading this one.
18 Hello World
20 A simple Hello World application can look like this, strict, warnings,
21 utf8 and Perl 5.16 features are automatically enabled and a few
22 functions imported, when you use Mojolicious::Lite, turning your script
23 into a full featured web application.
24 #!/usr/bin/env perl
26 use Mojolicious::Lite -signatures;
27 get '/' => sub ($c) {
29 $c->render(text => 'Hello World!');
30 };
31 app->start;
33 With Mojolicious::Command::Author::generate::lite_app there is also a
35 helper command to generate a small example application.
36 $ mojo generate lite-app myapp.pl
38 Commands
40 Many different commands are automatically available from the command
41 line. CGI and PSGI environments can even be detected and will usually
42 just work without commands.
43 $ ./myapp.pl daemon
45 Web application available at http://127.0.0.1:3000
46 $ ./myapp.pl daemon -l http://*:8080
48 Web application available at http://127.0.0.1:8080
49 $ ./myapp.pl cgi
51 ...CGI output...
52 $ ./myapp.pl get /
54 Hello World!
55 $ ./myapp.pl
57 ...List of available commands (or automatically detected environment)...
58 A call to "start" in Mojolicious ("app->start"), which starts the
60 command system, should be the last expression in your application,
61 because its return value can be significant.
62 # Use @ARGV to pick a command
64 app->start;
65 # Start the "daemon" command
67 app->start('daemon', '-l', 'http://*:8080');
68 Reloading
70 Your application will automatically reload itself if you start it with
71 the morbo development web server, so you don't have to restart the
72 server after every change.
73 $ morbo ./myapp.pl
75 Web application available at http://127.0.0.1:3000
76 For more information about how to deploy your application see also
78 "DEPLOYMENT" in Mojolicious::Guides::Cookbook.
79 Routes
81 Routes are basically just fancy paths that can contain different kinds
82 of placeholders and usually lead to an action, if they match the path
83 part of the request URL. The first argument passed to all actions ($c)
84 is a Mojolicious::Controller object, containing both the HTTP request
85 and response.
86 use Mojolicious::Lite -signatures;
88 # Route leading to an action that renders some text
90 get '/foo' => sub ($c) {
91 $c->render(text => 'Hello World!');
92 };
93 app->start;
95 Response content is often generated by actions with "render" in
97 Mojolicious::Controller, but more about that later.
98 GET/POST parameters
100 All "GET" and "POST" parameters sent with the request are accessible
101 via "param" in Mojolicious::Controller.
102 use Mojolicious::Lite -signatures;
104 # /foo?user=sri
106 get '/foo' => sub ($c) {
107 my $user = $c->param('user');
108 $c->render(text => "Hello $user.");
109 };
110 app->start;
112 Stash and templates
114 The "stash" in Mojolicious::Controller is used to pass data to
115 templates, which can be inlined in the "DATA" section. A few stash
116 values like "template", "text" and "data" are reserved and will be used
117 by "render" in Mojolicious::Controller to decide how a response should
118 be generated.
119 use Mojolicious::Lite -signatures;
121 # Route leading to an action that renders a template
123 get '/foo' => sub ($c) {
124 $c->stash(one => 23);
125 $c->render(template => 'magic', two => 24);
126 };
127 app->start;
129 __DATA__
130 @@ magic.html.ep
132 The magic numbers are <%= $one %> and <%= $two %>.
133 For more information about templates see also "Embedded Perl" in
135 Mojolicious::Guides::Rendering.
136 HTTP
138 "req" in Mojolicious::Controller and "res" in Mojolicious::Controller
139 give you full access to all HTTP features and information.
140 use Mojolicious::Lite -signatures;
142 # Access request information
144 get '/agent' => sub ($c) {
145 my $host = $c->req->url->to_abs->host;
146 my $ua = $c->req->headers->user_agent;
147 $c->render(text => "Request by $ua reached $host.");
148 };
149 # Echo the request body and send custom header with response
151 post '/echo' => sub ($c) {
152 $c->res->headers->header('X-Bender' => 'Bite my shiny metal ass!');
153 $c->render(data => $c->req->body);
154 };
155 app->start;
157 You can test the more advanced examples right from the command line
159 with Mojolicious::Command::get.
160 $ ./myapp.pl get -v -M POST -c 'test' /echo
162 JSON
164 JSON is the most commonly used data-interchange format for web
165 services. Mojolicious loves JSON and comes with the possibly fastest
166 pure-Perl implementation Mojo::JSON built right in, which is accessible
167 through "json" in Mojo::Message as well as the reserved stash value
168 "json".
169 use Mojolicious::Lite -signatures;
171 # Modify the received JSON document and return it
173 put '/reverse' => sub ($c) {
174 my $hash = $c->req->json;
175 $hash->{message} = reverse $hash->{message};
176 $c->render(json => $hash);
177 };
178 app->start;
180 You can send JSON documents from the command line with
182 Mojolicious::Command::get.
183 $ ./myapp.pl get -M PUT -c '{"message":"Hello Mojo!"}' /reverse
185 Built-in "exception" and "not_found" pages
187 During development you will encounter these pages whenever you make a
188 mistake, they are gorgeous and contain a lot of valuable information
189 that will aid you in debugging your application.
190 use Mojolicious::Lite -signatures;
192 # Not found (404)
194 get '/missing' => sub ($c) {
195 $c->render(template => 'does_not_exist');
196 };
197 # Exception (500)
199 get '/dies' => sub { die 'Intentional error' };
200 app->start;
202 You can even use CSS selectors with Mojolicious::Command::get to
204 extract only the information you're actually interested in.
205 $ ./myapp.pl get /dies '#error'
207 And don't worry about revealing too much information on these pages,
209 they are only available during development, and will be replaced
210 automatically with pages that don't reveal any sensitive information in
211 a production environment.
212 Route names
214 All routes can have a name associated with them, this allows automatic
215 template detection and backreferencing with "url_for" in
216 Mojolicious::Controller, on which many methods and helpers like
217 "link_to" in Mojolicious::Plugin::TagHelpers rely.
218 use Mojolicious::Lite -signatures;
220 # Render the template "index.html.ep"
222 get '/' => sub ($c) {
223 $c->render;
224 } => 'index';
225 # Render the template "hello.html.ep"
227 get '/hello';
228 app->start;
230 __DATA__
231 @@ index.html.ep
233 <%= link_to Hello => 'hello' %>.
234 <%= link_to Reload => 'index' %>.
235 @@ hello.html.ep
237 Hello World!
238 Nameless routes get an automatically generated one assigned that is
240 simply equal to the route itself without non-word characters.
241 Layouts
243 Templates can have layouts too, you just select one with the helper
244 "layout" in Mojolicious::Plugin::DefaultHelpers and place the result of
245 the current template with the helper "content" in
246 Mojolicious::Plugin::DefaultHelpers.
247 use Mojolicious::Lite;
249 get '/with_layout';
251 app->start;
253 __DATA__
254 @@ with_layout.html.ep
256 % title 'Green';
257 % layout 'green';
258 Hello World!
259 @@ layouts/green.html.ep
261 <!DOCTYPE html>
262 <html>
263 <head><title><%= title %></title></head>
264 <body><%= content %></body>
265 </html>
266 The stash or helpers like "title" in
268 Mojolicious::Plugin::DefaultHelpers can be used to pass additional data
269 to the layout.
270 Blocks
272 Template blocks can be used like normal Perl functions and are always
273 delimited by the "begin" and "end" keywords, they are the foundation
274 for many helpers.
275 use Mojolicious::Lite;
277 get '/with_block' => 'block';
279 app->start;
281 __DATA__
282 @@ block.html.ep
284 % my $link = begin
285 % my ($url, $name) = @_;
286 Try <%= link_to $url => begin %><%= $name %><% end %>.
287 % end
288 <!DOCTYPE html>
289 <html>
290 <head><title>Sebastians frameworks</title></head>
291 <body>
292 %= $link->('http://mojolicious.org', 'Mojolicious')
293 %= $link->('http://catalystframework.org', 'Catalyst')
294 </body>
295 </html>
296 Helpers
298 Helpers are little functions you can create with the keyword "helper"
299 in Mojolicious::Lite and reuse throughout your whole application, from
300 actions to templates.
301 use Mojolicious::Lite -signatures;
303 # A helper to identify visitors
305 helper whois => sub ($c) {
306 my $agent = $c->req->headers->user_agent || 'Anonymous';
307 my $ip = $c->tx->remote_address;
308 return "$agent ($ip)";
309 };
310 # Use helper in action and template
312 get '/secret' => sub ($c) {
313 my $user = $c->whois;
314 $c->app->log->debug("Request from $user");
315 };
316 app->start;
318 __DATA__
319 @@ secret.html.ep
321 We know who you are <%= whois %>.
322 A list of all built-in ones can be found in
324 Mojolicious::Plugin::DefaultHelpers and
325 Mojolicious::Plugin::TagHelpers.
326 Plugins
328 Plugins are application extensions that help with code sharing and
329 organization. You can load a plugin with the keyword "plugin" in
330 Mojolicious::Lite, which can omit the "Mojolicious::Plugin::" part of
331 the name, and optionally provide configuration for the plugin.
332 use Mojolicious::Lite;
334 plugin Config => {file => '/etc/myapp.conf', default => {foo => 'bar'}};
336 # Return configured foo value, or default if no configuration file
338 get '/foo' => sub ($c) {
339 my $foo = $c->app->config('foo');
340 $c->render(json => {foo => $foo});
341 };
342 app->start;
344 Mojolicious::Plugin::Config is a built-in plugin which can populate
346 "config" in Mojolicious using a config file. Plugins can also set up
347 routes, hooks, handlers, or even load other plugins. A list of built-in
348 plugins can be found at "PLUGINS" in Mojolicious::Plugins, and many
349 more are available from CPAN
350 <https://metacpan.org/search?q=Mojolicious+Plugin>.
351 Placeholders
353 Route placeholders allow capturing parts of a request path until a "/"
354 or "." separator occurs, similar to the regular expression "([^/.]+)".
355 Results are accessible via "stash" in Mojolicious::Controller and
356 "param" in Mojolicious::Controller.
357 use Mojolicious::Lite -signatures;
359 # /foo/test
361 # /foo/test123
362 get '/foo/:bar' => sub ($c) {
363 my $bar = $c->stash('bar');
364 $c->render(text => "Our :bar placeholder matched $bar");
365 };
366 # /testsomething/foo
368 # /test123something/foo
369 get '/<:bar>something/foo' => sub ($c) {
370 my $bar = $c->param('bar');
371 $c->render(text => "Our :bar placeholder matched $bar");
372 };
373 app->start;
375 To separate them from the surrounding text, you can surround your
377 placeholders with "<" and ">", which also makes the colon prefix
378 optional.
379 Relaxed Placeholders
381 Relaxed placeholders allow matching of everything until a "/" occurs,
382 similar to the regular expression "([^/]+)".
383 use Mojolicious::Lite;
385 # /hello/test
387 # /hello/test.html
388 get '/hello/#you' => 'groovy';
389 app->start;
391 __DATA__
392 @@ groovy.html.ep
394 Your name is <%= $you %>.
395 Wildcard placeholders
397 Wildcard placeholders allow matching absolutely everything, including
398 "/" and ".", similar to the regular expression "(.+)".
399 use Mojolicious::Lite;
401 # /hello/test
403 # /hello/test123
404 # /hello/test.123/test/123
405 get '/hello/*you' => 'groovy';
406 app->start;
408 __DATA__
409 @@ groovy.html.ep
411 Your name is <%= $you %>.
412 HTTP methods
414 Routes can be restricted to specific request methods with different
415 keywords like "get" in Mojolicious::Lite and "any" in
416 Mojolicious::Lite.
417 use Mojolicious::Lite -signatures;
419 # GET /hello
421 get '/hello' => sub ($c) {
422 $c->render(text => 'Hello World!');
423 };
424 # PUT /hello
426 put '/hello' => sub ($c) {
427 my $size = length $c->req->body;
428 $c->render(text => "You uploaded $size bytes to /hello.");
429 };
430 # GET|POST|PATCH /bye
432 any ['GET', 'POST', 'PATCH'] => '/bye' => sub ($c) {
433 $c->render(text => 'Bye World!');
434 };
435 # * /whatever
437 any '/whatever' => sub ($c) {
438 my $method = $c->req->method;
439 $c->render(text => "You called /whatever with $method.");
440 };
441 app->start;
443 Optional placeholders
445 All placeholders require a value, but by assigning them default values
446 you can make capturing optional.
447 use Mojolicious::Lite -signatures;
449 # /hello
451 # /hello/Sara
452 get '/hello/:name' => {name => 'Sebastian', day => 'Monday'} => sub ($c) {
453 $c->render(template => 'groovy', format => 'txt');
454 };
455 app->start;
457 __DATA__
458 @@ groovy.txt.ep
460 My name is <%= $name %> and it is <%= $day %>.
461 Default values that don't belong to a placeholder simply get merged
463 into the stash all the time.
464 Restrictive placeholders
466 A very easy way to make placeholders more restrictive are alternatives,
467 you just make a list of possible values.
468 use Mojolicious::Lite -signatures;
470 # /test
472 # /123
473 any '/:foo' => [foo => ['test', '123']] => sub ($c) {
474 my $foo = $c->param('foo');
475 $c->render(text => "Our :foo placeholder matched $foo");
476 };
477 app->start;
479 All placeholders get compiled to a regular expression internally, this
481 process can also be customized. Just make sure not to use "^" and "$",
482 or capturing groups "(...)", non-capturing groups "(?:...)" are fine
483 though.
484 use Mojolicious::Lite -signatures;
486 # /1
488 # /123
489 any '/:bar' => [bar => qr/\d+/] => sub ($c) {
490 my $bar = $c->param('bar');
491 $c->render(text => "Our :bar placeholder matched $bar");
492 };
493 app->start;
495 You can take a closer look at all the generated regular expressions
497 with the command Mojolicious::Command::routes.
498 $ ./myapp.pl routes -v
500 Under
502 Authentication and code shared between multiple routes can be realized
503 easily with routes generated by "under" in Mojolicious::Lite. All
504 following routes are only evaluated if the callback returned a true
505 value.
506 use Mojolicious::Lite -signatures;
508 # Authenticate based on name parameter
510 under sub ($c) {
511 # Authenticated
513 my $name = $c->param('name') || '';
514 return 1 if $name eq 'Bender';
515 # Not authenticated
517 $c->render(template => 'denied');
518 return undef;
519 };
520 # Only reached when authenticated
522 get '/' => 'index';
523 app->start;
525 __DATA__
526 @@ denied.html.ep
528 You are not Bender, permission denied.
529 @@ index.html.ep
531 Hi Bender.
532 Prefixing multiple routes is another good use for it.
534 use Mojolicious::Lite;
536 # /foo
538 under '/foo';
539 # /foo/bar
541 get '/bar' => {text => 'foo bar'};
542 # /foo/baz
544 get '/baz' => {text => 'foo baz'};
545 # / (reset)
547 under '/' => {msg => 'whatever'};
548 # /bar
550 get '/bar' => {inline => '<%= $msg %> works'};
551 app->start;
553 You can also group related routes with "group" in Mojolicious::Lite,
555 which allows nesting of routes generated with "under" in
556 Mojolicious::Lite.
557 use Mojolicious::Lite -signatures;
559 # Global logic shared by all routes
561 under sub ($c) {
562 return 1 if $c->req->headers->header('X-Bender');
563 $c->render(text => "You're not Bender.");
564 return undef;
565 };
566 # Admin section
568 group {
569 # Local logic shared only by routes in this group
571 under '/admin' => sub ($c) {
572 return 1 if $c->req->headers->header('X-Awesome');
573 $c->render(text => "You're not awesome enough.");
574 return undef;
575 };
576 # GET /admin/dashboard
578 get '/dashboard' => {text => 'Nothing to see here yet.'};
579 };
580 # GET /welcome
582 get '/welcome' => {text => 'Hi Bender.'};
583 app->start;
585 Formats
587 Formats can be automatically detected from file extensions like
588 ".html", they are used to find the right template and generate the
589 correct "Content-Type" header. Use a restrictive placeholder to declare
590 the possible values.
591 use Mojolicious::Lite -signatures;
593 # /detection.html
595 # /detection.txt
596 get '/detection' => [format => ['html', 'txt']] => sub ($c) {
597 $c->render(template => 'detected');
598 };
599 app->start;
601 __DATA__
602 @@ detected.html.ep
604 <!DOCTYPE html>
605 <html>
606 <head><title>Detected</title></head>
607 <body>HTML was detected.</body>
608 </html>
609 @@ detected.txt.ep
611 TXT was detected.
612 And just like with placeholders you can use a default value to make the
614 format optional.
615 use Mojolicious::Lite -signatures;
617 # /hello
619 # /hello.json
620 # /hello.txt
621 get '/hello' => [format => ['json', 'txt']] => {format => 'txt'} => sub ($c) {
622 return $c->render(json => {hello => 'world'}) if $c->stash('format') eq 'json';
623 $c->render(text => 'hello world');
624 };
625 app->start;
627 The default format is "html" and the renderer will fall back to when
629 necessary.
630 Content negotiation
632 For resources with different representations and that require truly
633 RESTful content negotiation you can also use "respond_to" in
634 Mojolicious::Plugin::DefaultHelpers.
635 use Mojolicious::Lite -signatures;
637 # /hello (Accept: application/json)
639 # /hello (Accept: application/xml)
640 # /hello.json
641 # /hello.xml
642 # /hello?_format=json
643 # /hello?_format=xml
644 get '/hello' => [format => ['json', 'xml']] => {format => undef} => sub ($c) {
645 $c->respond_to(
646 json => {json => {hello => 'world'}},
647 xml => {text => '<hello>world</hello>'},
648 any => {data => '', status => 204}
649 );
650 };
651 app->start;
653 MIME type mappings can be extended or changed easily with "types" in
655 Mojolicious.
656 app->types->type(rdf => 'application/rdf+xml');
658 Static files
660 Similar to templates, but with only a single file extension and
661 optional Base64 encoding, static files can be inlined in the "DATA"
662 section and are served automatically.
663 use Mojolicious::Lite;
665 app->start;
667 __DATA__
668 @@ something.js
670 alert('hello!');
671 @@ test.txt (base64)
673 dGVzdCAxMjMKbGFsYWxh
674 External static files are not limited to a single file extension and
676 will be served automatically from a "public" directory if it exists.
677 $ mkdir public
679 $ mv something.js public/something.js
680 $ mv mojolicious.tar.gz public/mojolicious.tar.gz
681 Both have a higher precedence than routes for "GET" and "HEAD"
683 requests. Content negotiation with "Range", "If-None-Match" and
684 "If-Modified-Since" headers is supported as well and can be tested very
685 easily with Mojolicious::Command::get.
686 $ ./myapp.pl get /something.js -v -H 'Range: bytes=2-4'
688 External templates
690 External templates will be searched by the renderer in a "templates"
691 directory if it exists.
692 $ mkdir -p templates/foo
694 $ echo 'Hello World!' > templates/foo/bar.html.ep
695 They have a higher precedence than templates in the "DATA" section.
697 use Mojolicious::Lite -signatures;
699 # Render template "templates/foo/bar.html.ep"
701 any '/external' => sub ($c) {
702 $c->render(template => 'foo/bar');
703 };
704 app->start;
706 Home
708 You can use "home" in Mojolicious to interact with the directory your
709 application considers its home. This is the directory it will search
710 for "public" and "templates" directories, but you can use it to store
711 all sorts of application specific data.
712 $ mkdir cache
714 $ echo 'Hello World!' > cache/hello.txt
715 There are many useful methods Mojo::Home inherits from Mojo::File, like
717 "child" in Mojo::File and "slurp" in Mojo::File, that will help you
718 keep your application portable across many different operating systems.
719 use Mojolicious::Lite -signatures;
721 # Load message into memory
723 my $hello = app->home->child('cache', 'hello.txt')->slurp;
724 # Display message
726 get '/' => sub ($c) {
727 $c->render(text => $hello);
728 };
729 You can also introspect your application from the command line with
731 Mojolicious::Command::eval.
732 $ ./myapp.pl eval -v 'app->home'
734 Conditions
736 Conditions such as "agent" and "host" from
737 Mojolicious::Plugin::HeaderCondition allow even more powerful route
738 constructs.
739 use Mojolicious::Lite -signatures;
741 # Firefox
743 get '/foo' => (agent => qr/Firefox/) => sub ($c) {
744 $c->render(text => 'Congratulations, you are using a cool browser.');
745 };
746 # Internet Explorer
748 get '/foo' => (agent => qr/Internet Explorer/) => sub ($c) {
749 $c->render(text => 'Dude, you really need to upgrade to Firefox.');
750 };
751 # http://mojolicious.org/bar
753 get '/bar' => (host => 'mojolicious.org') => sub ($c) {
754 $c->render(text => 'Hello Mojolicious.');
755 };
756 app->start;
758 Sessions
760 Cookie-based sessions just work out of the box, as soon as you start
761 using them through the helper "session" in
762 Mojolicious::Plugin::DefaultHelpers. Just be aware that all session
763 data gets serialized with Mojo::JSON and stored client-side, with a
764 cryptographic signature to prevent tampering.
765 use Mojolicious::Lite -signatures;
767 # Access session data in action and template
769 get '/counter' => sub ($c) {
770 $c->session->{counter}++;
771 };
772 app->start;
774 __DATA__
775 @@ counter.html.ep
777 Counter: <%= session 'counter' %>
778 Note that you should use custom "secrets" in Mojolicious to make signed
780 cookies really tamper resistant.
781 app->secrets(['My secret passphrase here']);
783 File uploads
785 All files uploaded via "multipart/form-data" request are automatically
786 available as Mojo::Upload objects from "param" in
787 Mojolicious::Controller. And you don't have to worry about memory
788 usage, because all files above 250KiB will be automatically streamed
789 into a temporary file. To build HTML forms more efficiently, you can
790 also use tag helpers like "form_for" in
791 Mojolicious::Plugin::TagHelpers.
792 use Mojolicious::Lite -signatures;
794 # Upload form in DATA section
796 get '/' => 'form';
797 # Multipart upload handler
799 post '/upload' => sub ($c) {
800 # Check file size
802 return $c->render(text => 'File is too big.', status => 200) if $c->req->is_limit_exceeded;
803 # Process uploaded file
805 return $c->redirect_to('form') unless my $example = $c->param('example');
806 my $size = $example->size;
807 my $name = $example->filename;
808 $c->render(text => "Thanks for uploading $size byte file $name.");
809 };
810 app->start;
812 __DATA__
813 @@ form.html.ep
815 <!DOCTYPE html>
816 <html>
817 <head><title>Upload</title></head>
818 <body>
819 %= form_for upload => (enctype => 'multipart/form-data') => begin
820 %= file_field 'example'
821 %= submit_button 'Upload'
822 % end
823 </body>
824 </html>
825 To protect you from excessively large files there is also a limit of
827 16MiB by default, which you can tweak with the attribute
828 "max_request_size" in Mojolicious.
829 # Increase limit to 1GiB
831 app->max_request_size(1073741824);
832 User agent
834 With Mojo::UserAgent, which is available through the helper "ua" in
835 Mojolicious::Plugin::DefaultHelpers, there's a full featured HTTP and
836 WebSocket user agent built right in. Especially in combination with
837 Mojo::JSON and Mojo::DOM this can be a very powerful tool.
838 use Mojolicious::Lite -signatures;
840 # Blocking
842 get '/headers' => sub ($c) {
843 my $url = $c->param('url') || 'https://mojolicious.org';
844 my $dom = $c->ua->get($url)->result->dom;
845 $c->render(json => $dom->find('h1, h2, h3')->map('text')->to_array);
846 };
847 # Non-blocking
849 get '/title' => sub ($c) {
850 $c->ua->get('mojolicious.org' => sub ($ua, $tx) {
851 $c->render(data => $tx->result->dom->at('title')->text);
852 });
853 };
854 # Concurrent non-blocking
856 get '/titles' => sub ($c) {
857 my $mojo = $c->ua->get_p('https://mojolicious.org');
858 my $cpan = $c->ua->get_p('https://metacpan.org');
859 Mojo::Promise->all($mojo, $cpan)->then(sub ($mojo, $cpan) {
860 $c->render(json => {
861 mojo => $mojo->[0]->result->dom->at('title')->text,
862 cpan => $cpan->[0]->result->dom->at('title')->text
863 });
864 })->wait;
865 };
866 app->start;
868 For more information about the user agent see also "USER AGENT" in
870 Mojolicious::Guides::Cookbook.
871 WebSockets
873 WebSocket applications have never been this simple before. Just receive
874 messages by subscribing to events such as "json" in
875 Mojo::Transaction::WebSocket with "on" in Mojolicious::Controller and
876 return them with "send" in Mojolicious::Controller.
877 use Mojolicious::Lite -signatures;
879 websocket '/echo' => sub ($c) {
881 $c->on(json => sub ($c, $hash) {
882 $hash->{msg} = "echo: $hash->{msg}";
883 $c->send({json => $hash});
884 });
885 };
886 get '/' => 'index';
888 app->start;
890 __DATA__
891 @@ index.html.ep
893 <!DOCTYPE html>
894 <html>
895 <head>
896 <title>Echo</title>
897 <script>
898 var ws = new WebSocket('<%= url_for('echo')->to_abs %>');
899 ws.onmessage = function (event) {
900 document.body.innerHTML += JSON.parse(event.data).msg;
901 };
902 ws.onopen = function (event) {
903 ws.send(JSON.stringify({msg: 'I ♥ Mojolicious!'}));
904 };
905 </script>
906 </head>
907 </html>
908 For more information about real-time web features see also "REAL-TIME
910 WEB" in Mojolicious::Guides::Cookbook.
911 Mode
913 You can use the Mojo::Log object from "log" in Mojolicious to portably
914 collect debug messages and automatically disable them later in a
915 production setup by changing the Mojolicious operating mode, which can
916 also be retrieved from the attribute "mode" in Mojolicious.
917 use Mojolicious::Lite -signatures;
919 # Prepare mode specific message during startup
921 my $msg = app->mode eq 'development' ? 'Development!' : 'Something else!';
922 get '/' => sub ($c) {
924 $c->app->log->debug('Rendering mode specific message');
925 $c->render(text => $msg);
926 };
927 app->log->debug('Starting application');
929 app->start;
930 The default operating mode will usually be "development" and can be
932 changed with command line options or the "MOJO_MODE" and "PLACK_ENV"
933 environment variables. A mode other than "development" will raise the
934 log level from "trace" to "info". All messages will be written to
935 "STDERR" by default.
936 $ ./myapp.pl daemon -m production
938 Mode changes also affect a few other aspects of the framework, such as
940 the built-in "exception" and "not_found" pages. Once you switch modes
941 from "development" to "production", no sensitive information will be
942 revealed on those pages anymore.
943 Testing
945 Testing your application is as easy as creating a "t" directory and
946 filling it with normal Perl tests like "t/basic.t", which can be a lot
947 of fun thanks to Test::Mojo.
948 use Test::More;
950 use Mojo::File qw(curfile);
951 use Test::Mojo;
952 # Portably point to "../myapp.pl"
954 my $script = curfile->dirname->sibling('myapp.pl');
955 my $t = Test::Mojo->new($script);
957 $t->get_ok('/')->status_is(200)->content_like(qr/Funky/);
958 done_testing();
960 Just run your tests with prove.
962 $ prove -l -v
964 $ prove -l -v t/basic.t
965
967 You can continue with Mojolicious::Guides now or take a look at the
968 Mojolicious wiki <https://github.com/mojolicious/mojo/wiki>, which
969 contains a lot more documentation and examples by many different
970 authors.
971
973 If you have any questions the documentation might not yet answer, don't
974 hesitate to ask in the Forum <https://forum.mojolicious.org> or the
975 official IRC channel "#mojo" on "irc.libera.chat" (chat now!
976 <https://web.libera.chat/#mojo>).
977perl v5.34.0 2022-01-21 Mojolicious::Guides::Tutorial(3)