5 use warnings::illegalproto ();
7 use Web::Dispatch::Wrapper ();
9 our $VERSION = '0.004';
12 my ($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
39 This is really quite new. If you're reading this on CPAN, it means the stuff
40 that's here we're probably happy with. But only probably. So we may have to
41 change stuff. And if you're reading this from git, come check with irc.perl.org
42 #web-simple that we're actually sure we're going to keep anything that's
43 different from the CPAN version.
45 If we do find we have to change stuff we'll add to the
46 L<CHANGES BETWEEN RELEASES> section explaining how to switch your code across
47 to the new version, and we'll do our best to make it as painless as possible
48 because we've got Web::Simple applications too. But we can't promise not to
49 change things at all. Not yet. Sorry.
55 use Web::Simple 'HelloWorld';
60 sub dispatch_request {
62 [ 200, [ 'Content-type', 'text/plain' ], [ 'Hello world!' ] ]
65 [ 405, [ 'Content-type', 'text/plain' ], [ 'Method not allowed' ] ]
70 HelloWorld->run_if_script;
72 If you save this file into your cgi-bin as hello-world.cgi and then visit
74 http://my.server.name/cgi-bin/hello-world.cgi/
76 you'll get the "Hello world!" string output to your browser. For more complex
77 examples and non-CGI deployment, see below. To get help with Web::Simple,
78 please connect to the irc.perl.org IRC network and join #web-simple.
82 Web::Simple was originally written to form part of my Antiquated Perl talk for
83 Italian Perl Workshop 2009, but in writing the bloggery example I realised
84 that having a bare minimum system for writing web applications that doesn't
85 drive me insane was rather nice and decided to spend my attempt at nanowrimo
86 for 2009 improving and documenting it to the point where others could use it.
88 The philosophy of Web::Simple is to keep to an absolute bare minimum, for
89 everything. It is not designed to be used for large scale applications;
90 the L<Catalyst> web framework already works very nicely for that and is
91 a far more mature, well supported piece of software.
93 However, if you have an application that only does a couple of things, and
94 want to not have to think about complexities of deployment, then Web::Simple
95 might be just the thing for you.
97 The Antiquated Perl talk can be found at L<http://www.shadowcat.co.uk/archive/conference-video/>.
101 The only public interface the Web::Simple module itself provides is an
104 use Web::Simple 'NameOfApplication';
106 This imports 'strict' and 'warnings FATAL => "all"' into your code as well,
107 so you can skip the usual
112 provided you 'use Web::Simple' at the top of the file. Note that we turn
113 on *fatal* warnings so if you have any warnings at any point from the file
114 that you did 'use Web::Simple' in, then your application will die. This is,
115 so far, considered a feature.
117 Calling the import also makes NameOfApplication isa Web::Simple::Application
118 and sets your app class up as a L<Moo> class- i.e. does the equivalent of
121 package NameOfApplication;
123 extends 'Web::Simple::Application';
126 It also exports the following subroutines for use in dispatchers:
128 response_filter { ... };
130 redispatch_to '/somewhere';
134 $INC{"NameOfApplication.pm"} = 'Set by "use Web::Simple;" invocation';
136 so that perl will not attempt to load the application again even if
138 require NameOfApplication;
140 is encountered in other code.
142 =head1 DISPATCH STRATEGY
146 sub dispatch_request {
147 # matches: GET /user/1.htm?show_details=1
149 sub (GET + /user/* + ?show_details~ + .htm|.html|.xhtml) {
150 my ($self, $user_id, $show_details) = @_;
153 # matches: POST /user?username=frew
154 # POST /user?username=mst&first_name=matt&last_name=trout
155 sub (POST + /user + ?username=&*) {
156 my ($self, $username, $misc_params) = @_;
159 # matches: DELETE /user/1/friend/2
160 sub (DELETE + /user/*/friend/*) {
161 my ($self, $user_id, $friend_id) = @_;
164 # matches: PUT /user/1?first_name=Matt&last_name=Trout
165 sub (PUT + /user/* + ?first_name~&last_name~) {
166 my ($self, $user_id, $first_name, $last_name) = @_;
171 # matches: PUT /user/1/role/1
172 sub (PUT + /role/*) {
176 # matches: DELETE /user/1/role/1
177 sub (DELETE + /role/*) {
184 =head2 The dispatch cycle
186 At the beginning of a request, your app's dispatch_request method is called
187 with the PSGI $env as an argument. You can handle the request entirely in
188 here and return a PSGI response arrayref if you want:
190 sub dispatch_request {
191 my ($self, $env) = @_;
192 [ 404, [ 'Content-type' => 'text/plain' ], [ 'Amnesia == fail' ] ]
195 However, generally, instead of that, you return a set of dispatch subs:
197 sub dispatch_request {
199 sub (/) { redispatch_to '/index.html' },
200 sub (/user/*) { $self->show_user($_[1]) },
204 If you return a subroutine with a prototype, the prototype is treated
205 as a match specification - and if the test is passed, the body of the
206 sub is called as a method any matched arguments (see below for more details).
208 You can also return a plain subroutine which will be called with just $env
209 - remember that in this case if you need $self you -must- close over it.
211 If you return a normal object, Web::Simple will simply return it upwards on
212 the assumption that a response_filter somewhere will convert it to something
213 useful - this allows:
215 sub dispatch_request {
217 sub (.html) { response_filter { $self->render_zoom($_[0]) } },
218 sub (/user/*) { $self->users->get($_[1]) },
221 to render a user object to HTML, for example.
223 However, two types of object are treated specially - a Plack::App object
224 will have its ->to_app method called and be used as a dispatcher:
226 sub dispatch_request {
228 sub (/static/...) { Plack::App::File->new(...) },
232 A Plack::Middleware object will be used as a filter for the rest of the
233 dispatch being returned into:
235 ## responds to /admin/track_usage AND /admin/delete_accounts
237 sub dispatch_request {
240 Plack::Middleware::Session->new(%opts);
242 sub (/admin/track_usage) {
243 ## something that needs a session
245 sub (/admin/delete_accounts) {
246 ## something else that needs a session
250 Note that this is for the dispatch being -returned- to, so if you want to
251 provide it inline you need to do:
253 ## ALSO responds to /admin/track_usage AND /admin/delete_accounts
255 sub dispatch_request {
259 Plack::Middleware::Session->new(%opts);
262 ## something that needs a session
264 sub (/delete_accounts) {
265 ## something else that needs a session
270 And that's it - but remember that all this happens recursively - it's
271 dispatchers all the way down.
273 =head2 Web::Simple match specifications
275 =head3 Method matches
279 A match specification beginning with a capital letter matches HTTP requests
280 with that request method.
286 A match specification beginning with a / is a path match. In the simplest
287 case it matches a specific path. To match a path with a wildcard part, you
291 $self->handle_user($_[1])
293 This will match /user/<anything> where <anything> does not include a literal
294 / character. The matched part becomes part of the match arguments. You can
295 also match more than one part:
298 my ($self, $user_1, $user_2) = @_;
300 sub (/domain/*/user/*) {
301 my ($self, $domain, $user) = @_;
303 and so on. To match an arbitrary number of parts, use -
307 This will result in an element per /-separated part so matched. Note that
310 sub (/page/**/edit) {
312 to match an arbitrary number of parts up to but not including some final
319 will match /foo/ on the beginning of the path -and- strip it, much like
320 .html strips the extension. This is designed to be used to construct
321 nested dispatch structures, but can also prove useful for having e.g. an
322 optional language specification at the start of a path.
324 Note that the '...' is a "maybe something here, maybe not" so the above
325 specification will match like this:
328 /foo/ # match and strip path to '/'
329 /foo/bar/baz # match and strip path to '/bar/baz'
331 =head3 Extension matches
335 will match and strip .html from the path (assuming the subroutine itself
336 returns something, of course). This is normally used for rendering - e.g.
339 response_filter { $self->render_html($_[1]) }
346 will match any extension and supplies the stripped extension as a match
349 =head3 Query and body parameter matches
351 Query and body parameters can be match via
353 sub (?<param spec>) { # match URI query
354 sub (%<param spec>) { # match body params
356 The body is only matched if the content type is
357 application/x-www-form-urlencoded (note this means that Web::Simple does
358 not yet handle uploads; this will be addressed in a later release).
360 The param spec is elements of one of the following forms -
362 param~ # optional parameter
363 param= # required parameter
364 @param~ # optional multiple parameter
365 @param= # required multiple parameter
366 :param~ # optional parameter in hashref
367 :param= # required parameter in hashref
368 :@param~ # optional multiple in hashref
369 :@param= # required multiple in hashref
370 * # include all other parameters in hashref
371 @* # include all other parameters as multiple in hashref
373 separated by the & character. The arguments added to the request are
374 one per non-:/* parameter (scalar for normal, arrayref for multiple),
375 plus if any :/* specs exist a hashref containing those values.
377 So, to match a page parameter with an optional order_by parameter one
380 sub (?page=&order_by~) {
381 my ($self, $page, $order_by) = @_;
382 return unless $page =~ /^\d+$/;
385 $_[1]->search_rs({}, $p);
389 to implement paging and ordering against a L<DBIx::Class::ResultSet> object.
391 Note that if a parameter is specified as single and multiple values are found,
392 the last one will be used.
394 To get all parameters as a hashref of arrayrefs, write:
397 my ($self, $params) = @_;
400 To get two parameters as a hashref, write:
402 sub(?:user~&:domain~) {
403 my ($self, $params) = @_; # params contains only 'user' and 'domain' keys
405 You can also mix these, so:
407 sub (?foo=&@bar~&:coffee=&@*) {
408 my ($self, $foo, $bar, $params);
410 where $bar is an arrayref (possibly an empty one), and $params contains
411 arrayref values for all parameters -not- mentioned and a scalar value for
412 the 'coffee' parameter.
414 =head3 Combining matches
416 Matches may be combined with the + character - e.g.
418 sub (GET + /user/*) {
420 to create an AND match. They may also be combined withe the | character - e.g.
424 to create an OR match. Matches can be nested with () - e.g.
426 sub ((GET|POST) + /user/*) {
428 and negated with ! - e.g.
430 sub (!/user/foo + /user/*) {
432 ! binds to the immediate rightmost match specification, so if you want
433 to negate a combination you will need to use
435 sub ( !(POST|PUT|DELETE) ) {
437 and | binds tighter than +, so
439 sub ((GET|POST) + /user/*) {
443 sub (GET|POST + /user/*) {
447 sub ((GET + .html) | (POST + .html)) {
451 sub (GET + .html | POST + .html) {
453 are not - the latter is equivalent to
455 sub (GET + (.html|POST) + .html) {
457 which will never match.
461 Note that for legibility you are permitted to use whitespace -
463 sub (GET + /user/*) {
465 but it will be ignored. This is because the perl parser strips whitespace
466 from subroutine prototypes, so this is equivalent to
470 =head3 Accessing the PSGI env hash
472 In some cases you may wish to get the raw PSGI env hash - to do this,
473 you can either use a plain sub -
480 or use the PSGI_ENV constant exported to retrieve it:
482 sub (GET + /foo + ?some_param=) {
484 my $env = $_[PSGI_ENV];
487 but note that if you're trying to add a middleware, you should simply use
488 Web::Simple's direct support for doing so.
490 =head1 EXPORTED SUBROUTINES
492 =head2 response_filter
495 # Hide errors from the user because we hates them, preciousss
496 if (ref($_[0]) eq 'ARRAY' && $_[0]->[0] == 500) {
497 $_[0] = [ 200, @{$_[0]}[1..$#{$_[0]}] ];
502 The response_filter subroutine is designed for use inside dispatch subroutines.
504 It creates and returns a special dispatcher that always matches, and calls
505 the block passed to it as a filter on the result of running the rest of the
506 current dispatch chain.
508 Thus the filter above runs further dispatch as normal, but if the result of
509 dispatch is a 500 (Internal Server Error) response, changes this to a 200 (OK)
510 response without altering the headers or body.
514 redispatch_to '/other/url';
516 The redispatch_to subroutine is designed for use inside dispatch subroutines.
518 It creates and returns a special dispatcher that always matches, and instead
519 of continuing dispatch re-delegates it to the start of the dispatch process,
520 but with the path of the request altered to the supplied URL.
522 Thus if you receive a POST to '/some/url' and return a redispatch to
523 '/other/url', the dispatch behaviour will be exactly as if the same POST
524 request had been made to '/other/url' instead.
526 =head1 CHANGES BETWEEN RELEASES
528 =head2 Changes between 0.004 and 0.005
532 =item * dispatch {} replaced by declaring a dispatch_request method
534 dispatch {} has gone away - instead, you write:
536 sub dispatch_request {
538 sub (GET /foo/) { ... },
542 Note that this method is still -returning- the dispatch code - just like
545 Also note that you need the 'my $self = shift' since the magic $self
548 =item * the magic $self variable went away.
550 Just add 'my $self = shift;' while writing your 'sub dispatch_request {'
551 like a normal perl method.
553 =item * subdispatch deleted - all dispatchers can now subdispatch
555 In earlier releases you needed to write:
557 subdispatch sub (/foo/...) {
560 sub (GET /bar/) { ... },
565 As of 0.005, you can instead write simply:
570 sub (GET /bar/) { ... },
575 =head2 Changes since Antiquated Perl
579 =item * filter_response renamed to response_filter
581 This is a pure rename; a global search and replace should fix it.
583 =item * dispatch [] changed to dispatch {}
587 dispatch [ sub(...) { ... }, ... ];
591 dispatch { sub(...) { ... }, ... };
597 =head1 COMMUNITY AND SUPPORT
601 irc.perl.org #web-simple
603 =head2 No mailing list yet
605 Because mst's non-work email is a bombsite so he'd never read it anyway.
607 =head2 Git repository
609 Gitweb is on http://git.shadowcat.co.uk/ and the clone URL is:
611 git clone git://git.shadowcat.co.uk/catagits/Web-Simple.git
615 Matt S. Trout <mst@shadowcat.co.uk>
619 None required yet. Maybe this module is perfect (hahahahaha ...).
623 Copyright (c) 2009 the Web::Simple L</AUTHOR> and L</CONTRIBUTORS>
628 This library is free software and may be distributed under the same terms