5 use warnings::illegalproto ();
7 use Web::Dispatch::Wrapper ();
9 our $VERSION = '0.010';
12 my ($class, $app_package) = @_;
13 $app_package ||= caller;
14 $class->_export_into($app_package);
15 eval "package $app_package; use Web::Dispatch::Wrapper; use Moo; 1"
16 or die "Failed to setup app package: $@";
18 warnings::illegalproto->unimport;
22 my ($class, $app_package) = @_;
25 *{"${app_package}::PSGI_ENV"} = sub () { -1 };
26 require Web::Simple::Application;
27 unshift(@{"${app_package}::ISA"}, 'Web::Simple::Application');
29 (my $name = $app_package) =~ s/::/\//g;
30 $INC{"${name}.pm"} = 'Set by "use Web::Simple;" invocation';
35 Web::Simple - A quick and easy way to build simple web applications
45 sub dispatch_request {
47 [ 200, [ 'Content-type', 'text/plain' ], [ 'Hello world!' ] ]
50 [ 405, [ 'Content-type', 'text/plain' ], [ 'Method not allowed' ] ]
54 HelloWorld->run_if_script;
56 If you save this file into your cgi-bin as C<hello-world.cgi> and then visit:
58 http://my.server.name/cgi-bin/hello-world.cgi/
60 you'll get the "Hello world!" string output to your browser. At the same time
61 this file will also act as a class module, so you can save it as HelloWorld.pm
62 and use it as-is in test scripts or other deployment mechanisms.
64 Note that you should retain the ->run_if_script even if your app is a
65 module, since this additionally makes it valid as a .psgi file, which can
66 be extremely useful during development.
68 For more complex examples and non-CGI deployment, see
69 L<Web::Simple::Deployment>. To get help with L<Web::Simple>, please connect to
70 the irc.perl.org IRC network and join #web-simple.
74 The philosophy of L<Web::Simple> is to keep to an absolute bare minimum for
75 everything. It is not designed to be used for large scale applications;
76 the L<Catalyst> web framework already works very nicely for that and is
77 a far more mature, well supported piece of software.
79 However, if you have an application that only does a couple of things, and
80 want to not have to think about complexities of deployment, then L<Web::Simple>
81 might be just the thing for you.
83 The only public interface the L<Web::Simple> module itself provides is an
86 use Web::Simple 'NameOfApplication';
88 This sets up your package (in this case "NameOfApplication" is your package)
89 so that it inherits from L<Web::Simple::Application> and imports L<strictures>,
90 as well as installs a C<PSGI_ENV> constant for convenience, as well as some
93 Importing L<strictures> will automatically make your code use the C<strict> and
94 C<warnings> pragma, so you can skip the usual:
97 use warnings FATAL => 'aa';
99 provided you 'use Web::Simple' at the top of the file. Note that we turn
100 on *fatal* warnings so if you have any warnings at any point from the file
101 that you did 'use Web::Simple' in, then your application will die. This is,
102 so far, considered a feature.
104 When we inherit from L<Web::Simple::Application> we also use L<Moo>, which is
105 the the equivalent of:
108 package NameOfApplication;
110 extends 'Web::Simple::Application';
113 So you can use L<Moo> features in your application, such as creating attributes
114 using the C<has> subroutine, etc. Please see the documentation for L<Moo> for
117 It also exports the following subroutines for use in dispatchers:
119 response_filter { ... };
121 redispatch_to '/somewhere';
125 $INC{"NameOfApplication.pm"} = 'Set by "use Web::Simple;" invocation';
127 so that perl will not attempt to load the application again even if
129 require NameOfApplication;
131 is encountered in other code.
133 =head1 DISPATCH STRATEGY
135 L<Web::Simple> despite being straightforward to use, has a powerful system
136 for matching all sorts of incoming URLs to one or more subroutines. These
137 subroutines can be simple actions to take for a given URL, or something
138 more complicated, including entire L<Plack> applications, L<Plack::Middleware>
139 and nested subdispatchers.
143 sub dispatch_request {
144 # matches: GET /user/1.htm?show_details=1
146 sub (GET + /user/* + ?show_details~ + .htm|.html|.xhtml) {
147 my ($self, $user_id, $show_details) = @_;
150 # matches: POST /user?username=frew
151 # POST /user?username=mst&first_name=matt&last_name=trout
152 sub (POST + /user + ?username=&*) {
153 my ($self, $username, $misc_params) = @_;
156 # matches: DELETE /user/1/friend/2
157 sub (DELETE + /user/*/friend/*) {
158 my ($self, $user_id, $friend_id) = @_;
161 # matches: PUT /user/1?first_name=Matt&last_name=Trout
162 sub (PUT + /user/* + ?first_name~&last_name~) {
163 my ($self, $user_id, $first_name, $last_name) = @_;
168 # matches: PUT /user/1/role/1
169 sub (PUT + /role/*) {
173 # matches: DELETE /user/1/role/1
174 sub (DELETE + /role/*) {
181 =head2 The dispatch cycle
183 At the beginning of a request, your app's dispatch_request method is called
184 with the PSGI $env as an argument. You can handle the request entirely in
185 here and return a PSGI response arrayref if you want:
187 sub dispatch_request {
188 my ($self, $env) = @_;
189 [ 404, [ 'Content-type' => 'text/plain' ], [ 'Amnesia == fail' ] ]
192 However, generally, instead of that, you return a set of dispatch subs:
194 sub dispatch_request {
196 sub (/) { redispatch_to '/index.html' },
197 sub (/user/*) { $self->show_user($_[1]) },
201 If you return a subroutine with a prototype, the prototype is treated
202 as a match specification - and if the test is passed, the body of the
203 sub is called as a method any matched arguments (see below for more details).
205 You can also return a plain subroutine which will be called with just $env
206 - remember that in this case if you need $self you -must- close over it.
208 If you return a normal object, L<Web::Simple> will simply return it upwards on
209 the assumption that a response_filter (or some arbitrary L<Plack::Middleware>)
210 somewhere will convert it to something useful. This allows:
212 sub dispatch_request {
214 sub (.html) { response_filter { $self->render_zoom($_[0]) } },
215 sub (/user/*) { $self->users->get($_[1]) },
218 to render a user object to HTML, if there is an incoming URL such as:
220 http://myweb.org/user/111.html
222 This works because as we descend down the dispachers, we first match
223 C<sub (.html)>, which adds a C<response_filter> (basically a specialized routine
224 that follows the L<Plack::Middleware> specification), and then later we also
225 match C<sub (/user/*)> which gets a user and returns that as the response.
226 This user object 'bubbles up' through all the wrapping middleware until it hits
227 the C<response_filter> we defined, after which the return is converted to a
230 However, two types of object are treated specially - a Plack::App object
231 will have its C<->to_app> method called and be used as a dispatcher:
233 sub dispatch_request {
235 sub (/static/...) { Plack::App::File->new(...) },
239 A Plack::Middleware object will be used as a filter for the rest of the
240 dispatch being returned into:
242 ## responds to /admin/track_usage AND /admin/delete_accounts
244 sub dispatch_request {
247 Plack::Middleware::Session->new(%opts);
249 sub (/admin/track_usage) {
250 ## something that needs a session
252 sub (/admin/delete_accounts) {
253 ## something else that needs a session
257 Note that this is for the dispatch being -returned- to, so if you want to
258 provide it inline you need to do:
260 ## ALSO responds to /admin/track_usage AND /admin/delete_accounts
262 sub dispatch_request {
266 Plack::Middleware::Session->new(%opts);
269 ## something that needs a session
271 sub (/delete_accounts) {
272 ## something else that needs a session
277 And that's it - but remember that all this happens recursively - it's
278 dispatchers all the way down. A URL incoming pattern will run all matching
279 dispatchers and then hit all added filters or L<Plack::Middleware>.
281 =head2 Web::Simple match specifications
283 =head3 Method matches
287 A match specification beginning with a capital letter matches HTTP requests
288 with that request method.
294 A match specification beginning with a / is a path match. In the simplest
295 case it matches a specific path. To match a path with a wildcard part, you
299 $self->handle_user($_[1])
301 This will match /user/<anything> where <anything> does not include a literal
302 / character. The matched part becomes part of the match arguments. You can
303 also match more than one part:
306 my ($self, $user_1, $user_2) = @_;
308 sub (/domain/*/user/*) {
309 my ($self, $domain, $user) = @_;
311 and so on. To match an arbitrary number of parts, use -
315 This will result in an element per /-separated part so matched. Note that
318 sub (/page/**/edit) {
320 to match an arbitrary number of parts up to but not including some final
327 Will match /foo/ on the beginning of the path -and- strip it. This is designed
328 to be used to construct nested dispatch structures, but can also prove useful
329 for having e.g. an optional language specification at the start of a path.
331 Note that the '...' is a "maybe something here, maybe not" so the above
332 specification will match like this:
335 /foo/ # match and strip path to '/'
336 /foo/bar/baz # match and strip path to '/bar/baz'
338 Note: Since Web::Simple handles a concept of file extensions, * and **
339 matchers will not by default match things after a final dot, and this
340 can be modified by using *.* and **.* in the final position, i.e.:
342 /one/* matches /one/two.three and captures "two"
343 /one/*.* matches /one/two.three and captures "two.three"
344 /** matches /one/two.three and captures "one/two"
345 /**.* matches /one/two.three and captures "one/two.three"
347 =head3 Extension matches
351 will match .html from the path (assuming the subroutine itself returns
352 something, of course). This is normally used for rendering - e.g.
355 response_filter { $self->render_html($_[1]) }
362 will match any extension and supplies the extension as a match argument.
364 =head3 Query and body parameter matches
366 Query and body parameters can be match via
368 sub (?<param spec>) { # match URI query
369 sub (%<param spec>) { # match body params
371 The body spec will match if the request content is either
372 application/x-www-form-urlencoded or multipart/form-data - the latter
373 of which is required for uploads, which are now handled experimentally
376 The param spec is elements of one of the following forms -
378 param~ # optional parameter
379 param= # required parameter
380 @param~ # optional multiple parameter
381 @param= # required multiple parameter
382 :param~ # optional parameter in hashref
383 :param= # required parameter in hashref
384 :@param~ # optional multiple in hashref
385 :@param= # required multiple in hashref
386 * # include all other parameters in hashref
387 @* # include all other parameters as multiple in hashref
389 separated by the & character. The arguments added to the request are
390 one per non-:/* parameter (scalar for normal, arrayref for multiple),
391 plus if any :/* specs exist a hashref containing those values.
393 Please note that if you specify a multiple type parameter match, you are
394 ensured of getting an arrayref for the value, EVEN if the current incoming
395 request has only one value. However if a parameter is specified as single
396 and multiple values are found, the last one will be used.
398 For example to match a page parameter with an optional order_by parameter one
401 sub (?page=&order_by~) {
402 my ($self, $page, $order_by) = @_;
403 return unless $page =~ /^\d+$/;
406 $_[1]->search_rs({}, $p);
410 to implement paging and ordering against a L<DBIx::Class::ResultSet> object.
412 Another Example: To get all parameters as a hashref of arrayrefs, write:
415 my ($self, $params) = @_;
418 To get two parameters as a hashref, write:
420 sub(?:user~&:domain~) {
421 my ($self, $params) = @_; # params contains only 'user' and 'domain' keys
423 You can also mix these, so:
425 sub (?foo=&@bar~&:coffee=&@*) {
426 my ($self, $foo, $bar, $params);
428 where $bar is an arrayref (possibly an empty one), and $params contains
429 arrayref values for all parameters -not- mentioned and a scalar value for
430 the 'coffee' parameter.
432 Note, in the case where you combine arrayref, single parameter and named
433 hashref style, the arrayref and single parameters will appear in C<@_> in the
434 order you defined them in the protoype, but all hashrefs will merge into a
435 single C<$params>, as in the example above.
437 =head3 Upload matches (EXPERIMENTAL)
439 Note: This feature is experimental. This means that it may not remain
440 100% in its current form. If we change it, notes on updating your code
441 will be added to the L</CHANGES BETWEEN RELEASES> section below.
443 sub (*foo=) { # param specifier can be anything valid for query or body
445 The upload match system functions exactly like a query/body match, except
446 that the values returned (if any) are C<Web::Dispatch::Upload> objects.
448 Note that this match type will succeed in two circumstances where you might
449 not expect it to - first, when the field exists but is not an upload field
450 and second, when the field exists but the form is not an upload form (i.e.
451 content type "application/x-www-form-urlencoded" rather than
452 "multipart/form-data"). In either of these cases, what you'll get back is
453 a C<Web::Dispatch::NotAnUpload> object, which will C<die> with an error
454 pointing out the problem if you try and use it. To be sure you have a real
457 $upload->is_upload # returns 1 on a valid upload, 0 on a non-upload field
459 and to get the reason why such an object is not an upload, call
461 $upload->reason # returns a reason or '' on a valid upload.
463 Other than these two methods, the upload object provides the same interface
464 as L<Plack::Request::Upload> with the addition of a stringify to the temporary
465 filename to make copying it somewhere else easier to handle.
467 =head3 Combining matches
469 Matches may be combined with the + character - e.g.
471 sub (GET + /user/*) {
473 to create an AND match. They may also be combined withe the | character - e.g.
477 to create an OR match. Matches can be nested with () - e.g.
479 sub ((GET|POST) + /user/*) {
481 and negated with ! - e.g.
483 sub (!/user/foo + /user/*) {
485 ! binds to the immediate rightmost match specification, so if you want
486 to negate a combination you will need to use
488 sub ( !(POST|PUT|DELETE) ) {
490 and | binds tighter than +, so
492 sub ((GET|POST) + /user/*) {
496 sub (GET|POST + /user/*) {
500 sub ((GET + /admin/...) | (POST + /admin/...)) {
504 sub (GET + /admin/... | POST + /admin/...) {
506 are not - the latter is equivalent to
508 sub (GET + (/admin/...|POST) + /admin/...) {
510 which will never match!
514 Note that for legibility you are permitted to use whitespace -
516 sub (GET + /user/*) {
518 but it will be ignored. This is because the perl parser strips whitespace
519 from subroutine prototypes, so this is equivalent to
523 =head3 Accessing the PSGI env hash
525 In some cases you may wish to get the raw PSGI env hash - to do this,
526 you can either use a plain sub -
533 or use the PSGI_ENV constant exported to retrieve it:
535 sub (GET + /foo + ?some_param=) {
537 my $env = $_[PSGI_ENV];
540 but note that if you're trying to add a middleware, you should simply use
541 Web::Simple's direct support for doing so.
543 =head1 EXPORTED SUBROUTINES
545 =head2 response_filter
548 # Hide errors from the user because we hates them, preciousss
549 if (ref($_[0]) eq 'ARRAY' && $_[0]->[0] == 500) {
550 $_[0] = [ 200, @{$_[0]}[1..$#{$_[0]}] ];
555 The response_filter subroutine is designed for use inside dispatch subroutines.
557 It creates and returns a special dispatcher that always matches, and calls
558 the block passed to it as a filter on the result of running the rest of the
559 current dispatch chain.
561 Thus the filter above runs further dispatch as normal, but if the result of
562 dispatch is a 500 (Internal Server Error) response, changes this to a 200 (OK)
563 response without altering the headers or body.
567 redispatch_to '/other/url';
569 The redispatch_to subroutine is designed for use inside dispatch subroutines.
571 It creates and returns a special dispatcher that always matches, and instead
572 of continuing dispatch re-delegates it to the start of the dispatch process,
573 but with the path of the request altered to the supplied URL.
575 Thus if you receive a POST to '/some/url' and return a redispatch to
576 '/other/url', the dispatch behaviour will be exactly as if the same POST
577 request had been made to '/other/url' instead.
579 Note, this is not the same as returning an HTTP 3xx redirect as a response;
580 rather it is a much more efficient internal process.
582 =head1 CHANGES BETWEEN RELEASES
584 =head2 Changes between 0.004 and 0.005
588 =item * dispatch {} replaced by declaring a dispatch_request method
590 dispatch {} has gone away - instead, you write:
592 sub dispatch_request {
594 sub (GET /foo/) { ... },
598 Note that this method is still -returning- the dispatch code - just like
601 Also note that you need the 'my $self = shift' since the magic $self
604 =item * the magic $self variable went away.
606 Just add 'my $self = shift;' while writing your 'sub dispatch_request {'
607 like a normal perl method.
609 =item * subdispatch deleted - all dispatchers can now subdispatch
611 In earlier releases you needed to write:
613 subdispatch sub (/foo/...) {
616 sub (GET /bar/) { ... },
621 As of 0.005, you can instead write simply:
626 sub (GET /bar/) { ... },
633 =head2 Changes since Antiquated Perl
637 =item * filter_response renamed to response_filter
639 This is a pure rename; a global search and replace should fix it.
641 =item * dispatch [] changed to dispatch {}
645 dispatch [ sub(...) { ... }, ... ];
649 dispatch { sub(...) { ... }, ... };
655 =head1 DEVELOPMENT HISTORY
657 Web::Simple was originally written to form part of my Antiquated Perl talk for
658 Italian Perl Workshop 2009, but in writing the bloggery example I realised
659 that having a bare minimum system for writing web applications that doesn't
660 drive me insane was rather nice and decided to spend my attempt at nanowrimo
661 for 2009 improving and documenting it to the point where others could use it.
663 The Antiquated Perl talk can be found at L<http://www.shadowcat.co.uk/archive/conference-video/> and the slides are reproduced in this distribution under
664 L<Web::Simple::AntiquatedPerl>.
666 =head1 COMMUNITY AND SUPPORT
670 irc.perl.org #web-simple
672 =head2 No mailing list yet
674 Because mst's non-work email is a bombsite so he'd never read it anyway.
676 =head2 Git repository
678 Gitweb is on http://git.shadowcat.co.uk/ and the clone URL is:
680 git clone git://git.shadowcat.co.uk/catagits/Web-Simple.git
684 Matt S. Trout (mst) <mst@shadowcat.co.uk>
688 Devin Austin (dhoss) <dhoss@cpan.org>
690 Arthur Axel 'fREW' Schmidt <frioux@gmail.com>
692 gregor herrmann (gregoa) <gregoa@debian.org>
694 John Napiorkowski (jnap) <jjn1056@yahoo.com>
696 Josh McMichael <jmcmicha@linus222.gsc.wustl.edu>
698 Justin Hunter <justin.d.hunter@gmail.com>
700 Kjetil Kjernsmo <kjetil@kjernsmo.net>
702 markie <markie@nulletch64.dreamhost.com>
704 Christian Walde (Mithaldu) <walde.christian@googlemail.com>
706 nperez <nperez@cpan.org>
708 Robin Edwards <robin.ge@gmail.com>
712 Copyright (c) 2010 the Web::Simple L</AUTHOR> and L</CONTRIBUTORS>
717 This library is free software and may be distributed under the same terms