Commit | Line | Data |
5c33dda5 |
1 | package Web::Simple; |
2 | |
3 | use strict; |
4 | use warnings FATAL => 'all'; |
8c4ffad3 |
5 | use 5.008; |
6 | |
7 | our $VERSION = '0.001'; |
5c33dda5 |
8 | |
44db8e76 |
9 | sub setup_all_strictures { |
5c33dda5 |
10 | strict->import; |
11 | warnings->import(FATAL => 'all'); |
44db8e76 |
12 | } |
13 | |
14 | sub setup_dispatch_strictures { |
15 | setup_all_strictures(); |
5c33dda5 |
16 | warnings->unimport('syntax'); |
17 | warnings->import(FATAL => qw( |
18 | ambiguous bareword digit parenthesis precedence printf |
19 | prototype qw reserved semicolon |
20 | )); |
44db8e76 |
21 | } |
22 | |
23 | sub import { |
24 | setup_dispatch_strictures(); |
5c33dda5 |
25 | my ($class, $app_package) = @_; |
26 | $class->_export_into($app_package); |
27 | } |
28 | |
29 | sub _export_into { |
30 | my ($class, $app_package) = @_; |
31 | { |
32 | no strict 'refs'; |
92e23550 |
33 | *{"${app_package}::dispatch"} = sub (&) { |
34 | $app_package->_setup_dispatcher([ $_[0]->() ]); |
5c33dda5 |
35 | }; |
74afe4b7 |
36 | *{"${app_package}::response_filter"} = sub (&) { |
5c33dda5 |
37 | $app_package->_construct_response_filter($_[0]); |
38 | }; |
39119082 |
39 | *{"${app_package}::redispatch_to"} = sub { |
40 | $app_package->_construct_redispatch($_[0]); |
41 | }; |
795c4698 |
42 | *{"${app_package}::subdispatch"} = sub ($) { |
43 | $app_package->_construct_subdispatch($_[0]); |
44 | }; |
5c33dda5 |
45 | *{"${app_package}::default_config"} = sub { |
44db8e76 |
46 | $app_package->_setup_default_config(@_); |
5c33dda5 |
47 | }; |
48 | *{"${app_package}::self"} = \${"${app_package}::self"}; |
49 | require Web::Simple::Application; |
50 | unshift(@{"${app_package}::ISA"}, 'Web::Simple::Application'); |
51 | } |
b7063124 |
52 | (my $name = $app_package) =~ s/::/\//g; |
53 | $INC{"${name}.pm"} = 'Set by "use Web::Simple;" invocation'; |
5c33dda5 |
54 | } |
55 | |
7401408e |
56 | =head1 NAME |
57 | |
58 | Web::Simple - A quick and easy way to build simple web applications |
59 | |
60 | =head1 WARNING |
61 | |
8c4ffad3 |
62 | This is really quite new. If you're reading this on CPAN, it means the stuff |
63 | that's here we're probably happy with. But only probably. So we may have to |
64 | change stuff. And if you're reading this from git, come check with irc.perl.org |
65 | #web-simple that we're actually sure we're going to keep anything that's |
66 | different from the CPAN version. |
7401408e |
67 | |
8c4ffad3 |
68 | If we do find we have to change stuff we'll add to the |
69 | L<CHANGES BETWEEN RELEASES> section explaining how to switch your code across |
70 | to the new version, and we'll do our best to make it as painless as possible |
71 | because we've got Web::Simple applications too. But we can't promise not to |
72 | change things at all. Not yet. Sorry. |
7401408e |
73 | |
74 | =head1 SYNOPSIS |
75 | |
76 | #!/usr/bin/perl |
77 | |
78 | use Web::Simple 'HelloWorld'; |
79 | |
80 | { |
81 | package HelloWorld; |
82 | |
92e23550 |
83 | dispatch { |
7401408e |
84 | sub (GET) { |
85 | [ 200, [ 'Content-type', 'text/plain' ], [ 'Hello world!' ] ] |
86 | }, |
87 | sub () { |
88 | [ 405, [ 'Content-type', 'text/plain' ], [ 'Method not allowed' ] ] |
89 | } |
33795c6a |
90 | }; |
7401408e |
91 | } |
92 | |
93 | HelloWorld->run_if_script; |
94 | |
95 | If you save this file into your cgi-bin as hello-world.cgi and then visit |
96 | |
97 | http://my.server.name/cgi-bin/hello-world.cgi/ |
98 | |
99 | you'll get the "Hello world!" string output to your browser. For more complex |
8c4ffad3 |
100 | examples and non-CGI deployment, see below. To get help with Web::Simple, |
101 | please connect to the irc.perl.org IRC network and join #web-simple. |
7401408e |
102 | |
103 | =head1 WHY? |
104 | |
da8429c9 |
105 | Web::Simple was originally written to form part of my Antiquated Perl talk for |
106 | Italian Perl Workshop 2009, but in writing the bloggery example I realised |
107 | that having a bare minimum system for writing web applications that doesn't |
108 | drive me insane was rather nice and decided to spend my attempt at nanowrimo |
109 | for 2009 improving and documenting it to the point where others could use it. |
7401408e |
110 | |
111 | The philosophy of Web::Simple is to keep to an absolute bare minimum, for |
112 | everything. It is not designed to be used for large scale applications; |
113 | the L<Catalyst> web framework already works very nicely for that and is |
114 | a far more mature, well supported piece of software. |
115 | |
116 | However, if you have an application that only does a couple of things, and |
117 | want to not have to think about complexities of deployment, then Web::Simple |
118 | might be just the thing for you. |
119 | |
120 | The Antiquated Perl talk can be found at L<http://www.shadowcat.co.uk/archive/conference-video/>. |
121 | |
122 | =head1 DESCRIPTION |
123 | |
124 | The only public interface the Web::Simple module itself provides is an |
125 | import based one - |
126 | |
127 | use Web::Simple 'NameOfApplication'; |
128 | |
129 | This imports 'strict' and 'warnings FATAL => "all"' into your code as well, |
130 | so you can skip the usual |
131 | |
132 | use strict; |
133 | use warnings; |
134 | |
135 | provided you 'use Web::Simple' at the top of the file. Note that we turn |
136 | on *fatal* warnings so if you have any warnings at any point from the file |
137 | that you did 'use Web::Simple' in, then your application will die. This is, |
138 | so far, considered a feature. |
139 | |
140 | Calling the import also makes NameOfApplication isa Web::Simple::Application |
141 | - i.e. does the equivalent of |
142 | |
143 | { |
144 | package NameOfApplication; |
145 | use base qw(Web::Simple::Application); |
146 | } |
147 | |
148 | It also exports the following subroutines: |
149 | |
150 | default_config( |
151 | key => 'value', |
152 | ... |
153 | ); |
154 | |
92e23550 |
155 | dispatch { sub (...) { ... }, ... }; |
7401408e |
156 | |
74afe4b7 |
157 | response_filter { ... }; |
7401408e |
158 | |
159 | redispatch_to '/somewhere'; |
160 | |
795c4698 |
161 | subdispatch sub (...) { ... } |
162 | |
44db8e76 |
163 | and creates a $self global variable in your application package, so you can |
7401408e |
164 | use $self in dispatch subs without violating strict (Web::Simple::Application |
165 | arranges for dispatch subroutines to have the correct $self in scope when |
166 | this happens). |
167 | |
b7063124 |
168 | Finally, import sets |
169 | |
170 | $INC{"NameOfApplication.pm"} = 'Set by "use Web::Simple;" invocation'; |
171 | |
172 | so that perl will not attempt to load the application again even if |
173 | |
174 | require NameOfApplication; |
175 | |
176 | is encountered in other code. |
177 | |
7401408e |
178 | =head1 EXPORTED SUBROUTINES |
179 | |
180 | =head2 default_config |
181 | |
182 | default_config( |
183 | one_key => 'foo', |
184 | another_key => 'bar', |
185 | ); |
186 | |
187 | ... |
188 | |
189 | $self->config->{one_key} # 'foo' |
190 | |
191 | This creates the default configuration for the application, by creating a |
192 | |
193 | sub _default_config { |
194 | return (one_key => 'foo', another_key => 'bar'); |
195 | } |
196 | |
197 | in the application namespace when executed. Note that this means that |
44db8e76 |
198 | you should only run default_config once - calling it a second time will |
199 | cause an exception to be thrown. |
7401408e |
200 | |
201 | =head2 dispatch |
202 | |
92e23550 |
203 | dispatch { |
7401408e |
204 | sub (GET) { |
205 | [ 200, [ 'Content-type', 'text/plain' ], [ 'Hello world!' ] ] |
206 | }, |
207 | sub () { |
208 | [ 405, [ 'Content-type', 'text/plain' ], [ 'Method not allowed' ] ] |
209 | } |
92e23550 |
210 | }; |
7401408e |
211 | |
44db8e76 |
212 | The dispatch subroutine calls NameOfApplication->_setup_dispatcher with |
92e23550 |
213 | the return value of the block passed to it, which then creates your Web::Simple |
214 | application's dispatcher from these subs. The prototype of each subroutine |
7401408e |
215 | is expected to be a Web::Simple dispatch specification (see |
216 | L</DISPATCH SPECIFICATIONS> below for more details), and the body of the |
451853d5 |
217 | subroutine is the code to execute if the specification matches. |
218 | |
92e23550 |
219 | Each dispatcher is given the dispatcher constructed from the next subroutine |
220 | returned as its next dispatcher, except for the final subroutine, which |
451853d5 |
221 | is given the return value of NameOfApplication->_build_final_dispatcher |
222 | as its next dispatcher (by default this returns a 500 error response). |
223 | |
224 | See L</DISPATCH STRATEGY> below for details on how the Web::Simple dispatch |
7401408e |
225 | system uses the return values of these subroutines to determine how to |
226 | continue, alter or abort dispatch. |
227 | |
44db8e76 |
228 | Note that _setup_dispatcher creates a |
7401408e |
229 | |
44db8e76 |
230 | sub _dispatcher { |
231 | return <root dispatcher object here>; |
7401408e |
232 | } |
233 | |
234 | method in your class so as with default_config, calling dispatch a second time |
44db8e76 |
235 | will result in an exception. |
7401408e |
236 | |
237 | =head2 response_filter |
238 | |
239 | response_filter { |
240 | # Hide errors from the user because we hates them, preciousss |
241 | if (ref($_[1]) eq 'ARRAY' && $_[1]->[0] == 500) { |
242 | $_[1] = [ 200, @{$_[1]}[1..$#{$_[1]}] ]; |
243 | } |
244 | return $_[1]; |
245 | }; |
246 | |
247 | The response_filter subroutine is designed for use inside dispatch subroutines. |
248 | |
44db8e76 |
249 | It creates and returns a special dispatcher that always matches, and calls |
250 | the block passed to it as a filter on the result of running the rest of the |
251 | current dispatch chain. |
252 | |
253 | Thus the filter above runs further dispatch as normal, but if the result of |
254 | dispatch is a 500 (Internal Server Error) response, changes this to a 200 (OK) |
255 | response without altering the headers or body. |
256 | |
257 | =head2 redispatch_to |
258 | |
259 | redispatch_to '/other/url'; |
260 | |
261 | The redispatch_to subroutine is designed for use inside dispatch subroutines. |
262 | |
263 | It creates and returns a special dispatcher that always matches, and instead |
264 | of continuing dispatch re-delegates it to the start of the dispatch process, |
265 | but with the path of the request altered to the supplied URL. |
266 | |
267 | Thus if you receive a POST to '/some/url' and return a redipstch to |
268 | '/other/url', the dispatch behaviour will be exactly as if the same POST |
269 | request had been made to '/other/url' instead. |
7401408e |
270 | |
795c4698 |
271 | =head2 subdispatch |
272 | |
273 | subdispatch sub (/user/*/) { |
274 | my $u = $self->user($_[1]); |
275 | [ |
276 | sub (GET) { $u }, |
277 | sub (DELETE) { $u->delete }, |
278 | ] |
279 | } |
280 | |
281 | The subdispatch subroutine is designed for use in dispatcher construction. |
282 | |
283 | It creates a dispatcher which, if it matches, treats its return value not |
284 | as a final value but an arrayref of dispatch specifications such as could |
285 | be passed to the dispatch subroutine itself. These are turned into a dispatcher |
286 | which is then invoked. Any changes the match makes to the request are in |
287 | scope for this inner dispatcher only - so if the initial match is a |
288 | destructive one like .html the full path will be restored if the |
289 | subdispatch fails. |
290 | |
3583ca04 |
291 | =head1 DISPATCH STRATEGY |
292 | |
81a5b03e |
293 | =head2 Description of the dispatcher object |
294 | |
295 | Web::Simple::Dispatcher objects have three components: |
296 | |
297 | =over 4 |
298 | |
299 | =item * match - an optional test if this dispatcher matches the request |
300 | |
301 | =item * call - a routine to call if this dispatcher matches (or has no match) |
302 | |
303 | =item * next - the next dispatcher to call |
304 | |
305 | =back |
306 | |
307 | When a dispatcher is invoked, it checks its match routine against the |
308 | request environment. The match routine may provide alterations to the |
309 | request as a result of matching, and/or arguments for the call routine. |
310 | |
311 | If no match routine has been provided then Web::Simple treats this as |
312 | a success, and supplies the request environment to the call routine as |
313 | an argument. |
314 | |
315 | Given a successful match, the call routine is now invoked in list context |
316 | with any arguments given to the original dispatch, plus any arguments |
317 | provided by the match result. |
318 | |
319 | If this routine returns (), Web::Simple treats this identically to a failure |
320 | to match. |
321 | |
322 | If this routine returns a Web::Simple::Dispatcher, the environment changes |
323 | are merged into the environment and the new dispatcher's next pointer is |
324 | set to our next pointer. |
325 | |
326 | If this routine returns anything else, that is treated as the end of dispatch |
327 | and the value is returned. |
328 | |
329 | On a failed match, Web::Simple invokes the next dispatcher with the same |
330 | arguments and request environment passed to the current one. On a successful |
331 | match that returned a new dispatcher, Web::Simple invokes the new dispatcher |
332 | with the same arguments but the modified request environment. |
333 | |
334 | =head2 How Web::Simple builds dispatcher objects for you |
335 | |
336 | In the case of the Web::Simple L</dispatch> export the match is constructed |
337 | from the subroutine prototype - i.e. |
338 | |
339 | sub (<match specification>) { |
340 | <call code> |
341 | } |
342 | |
343 | and the 'next' pointer is populated with the next element of the array, |
344 | expect for the last element, which is given a next that will throw a 500 |
345 | error if none of your dispatchers match. If you want to provide something |
346 | else as a default, a routine with no match specification always matches, so - |
347 | |
348 | sub () { |
349 | [ 404, [ 'Content-type', 'text/plain' ], [ 'Error: Not Found' ] ] |
350 | } |
351 | |
352 | will produce a 404 result instead of a 500 by default. You can also override |
353 | the L<Web::Simple::Application/_build_final_dispatcher> method in your app. |
354 | |
355 | Note that the code in the subroutine is executed as a -method- on your |
356 | application object, so if your match specification provides arguments you |
357 | should unpack them like so: |
358 | |
359 | sub (<match specification>) { |
360 | my ($self, @args) = @_; |
361 | ... |
362 | } |
363 | |
364 | =head2 Web::Simple match specifications |
365 | |
366 | =head3 Method matches |
367 | |
93e30ba3 |
368 | sub (GET) { |
15dfe701 |
369 | |
370 | A match specification beginning with a capital letter matches HTTP requests |
371 | with that request method. |
372 | |
81a5b03e |
373 | =head3 Path matches |
374 | |
15dfe701 |
375 | sub (/login) { |
376 | |
377 | A match specification beginning with a / is a path match. In the simplest |
378 | case it matches a specific path. To match a path with a wildcard part, you |
379 | can do: |
380 | |
381 | sub (/user/*) { |
382 | $self->handle_user($_[1]) |
383 | |
384 | This will match /user/<anything> where <anything> does not include a literal |
385 | / character. The matched part becomes part of the match arguments. You can |
386 | also match more than one part: |
387 | |
388 | sub (/user/*/*) { |
389 | my ($self, $user_1, $user_2) = @_; |
390 | |
391 | sub (/domain/*/user/*) { |
392 | my ($self, $domain, $user) = @_; |
393 | |
394 | and so on. To match an arbitrary number of parts, use - |
395 | |
396 | sub (/page/**) { |
397 | |
398 | This will result in an element per /-separated part so matched. Note that |
399 | you can do |
400 | |
401 | sub (/page/**/edit) { |
402 | |
403 | to match an arbitrary number of parts up to but not including some final |
404 | part. |
405 | |
da8429c9 |
406 | Finally, |
407 | |
408 | sub (/foo/...) { |
409 | |
410 | will match /foo/ on the beginning of the path -and- strip it, much like |
411 | .html strips the extension. This is designed to be used to construct |
412 | nested dispatch structures, but can also prove useful for having e.g. an |
413 | optional language specification at the start of a path. |
414 | |
415 | Note that the '...' is a "maybe something here, maybe not" so the above |
416 | specification will match like this: |
417 | |
418 | /foo # no match |
419 | /foo/ # match and strip path to '/' |
420 | /foo/bar/baz # match and strip path to '/bar/baz' |
421 | |
81a5b03e |
422 | =head3 Extension matches |
423 | |
15dfe701 |
424 | sub (.html) { |
425 | |
426 | will match and strip .html from the path (assuming the subroutine itself |
427 | returns something, of course). This is normally used for rendering - e.g. |
428 | |
429 | sub (.html) { |
74afe4b7 |
430 | response_filter { $self->render_html($_[1]) } |
15dfe701 |
431 | } |
432 | |
b8bd7bd1 |
433 | Additionally, |
434 | |
435 | sub (.*) { |
436 | |
437 | will match any extension and supplies the stripped extension as a match |
438 | argument. |
439 | |
9b9866ae |
440 | =head3 Query and body parameter matches |
441 | |
442 | Query and body parameters can be match via |
443 | |
444 | sub (?<param spec>) { # match URI query |
445 | sub (%<param spec>) { # match body params |
446 | |
447 | The body is only matched if the content type is |
448 | application/x-www-form-urlencoded (note this means that Web::Simple does |
449 | not yet handle uploads; this will be addressed in a later release). |
450 | |
451 | The param spec is elements of one of the following forms - |
452 | |
453 | param~ # optional parameter |
454 | param= # required parameter |
455 | @param~ # optional multiple parameter |
456 | @param= # required multiple parameter |
eb9e0e25 |
457 | :param~ # optional parameter in hashref |
458 | :param= # required parameter in hashref |
459 | :@param~ # optional multiple in hashref |
460 | :@param= # required multiple in hashref |
461 | * # include all other parameters in hashref |
462 | @* # include all other parameters as multiple in hashref |
9b9866ae |
463 | |
eb9e0e25 |
464 | separated by the & character. The arguments added to the request are |
465 | one per non-:/* parameter (scalar for normal, arrayref for multiple), |
466 | plus if any :/* specs exist a hashref containing those values. |
9b9866ae |
467 | |
468 | So, to match a page parameter with an optional order_by parameter one |
469 | would write: |
470 | |
471 | sub (?page=&order_by~) { |
eb9e0e25 |
472 | my ($self, $page, $order_by) = @_; |
473 | return unless $page =~ /^\d+$/; |
474 | $page ||= 'id'; |
9b9866ae |
475 | response_filter { |
476 | $_[1]->search_rs({}, $p); |
477 | } |
478 | } |
479 | |
480 | to implement paging and ordering against a L<DBIx::Class::ResultSet> object. |
481 | |
8c4ffad3 |
482 | Note that if a parameter is specified as single and multiple values are found, |
483 | the last one will be used. |
484 | |
eb9e0e25 |
485 | To get all parameters as a hashref of arrayrefs, write: |
486 | |
487 | sub(?@*) { |
488 | my ($self, $params) = @_; |
489 | ... |
490 | |
8c4ffad3 |
491 | To get two parameters as a hashref, write: |
492 | |
493 | sub(?:user~&:domain~) { |
494 | my ($self, $params) = @_; # params contains only 'user' and 'domain' keys |
495 | |
496 | You can also mix these, so: |
497 | |
498 | sub (?foo=&@bar~&:coffee=&@*) { |
499 | my ($self, $foo, $bar, $params); |
500 | |
501 | where $bar is an arrayref (possibly an empty one), and $params contains |
502 | arrayref values for all parameters -not- mentioned and a scalar value for |
503 | the 'coffee' parameter. |
504 | |
81a5b03e |
505 | =head3 Combining matches |
506 | |
15dfe701 |
507 | Matches may be combined with the + character - e.g. |
508 | |
b8bd7bd1 |
509 | sub (GET + /user/*) { |
510 | |
511 | to create an AND match. They may also be combined withe the | character - e.g. |
512 | |
513 | sub (GET|POST) { |
514 | |
515 | to create an OR match. Matches can be nested with () - e.g. |
516 | |
517 | sub ((GET|POST) + /user/*) { |
518 | |
519 | and negated with ! - e.g. |
520 | |
521 | sub (!/user/foo + /user/*) { |
522 | |
523 | ! binds to the immediate rightmost match specification, so if you want |
524 | to negate a combination you will need to use |
525 | |
526 | sub ( !(POST|PUT|DELETE) ) { |
527 | |
528 | and | binds tighter than +, so |
529 | |
530 | sub ((GET|POST) + /user/*) { |
531 | |
532 | and |
533 | |
534 | sub (GET|POST + /user/*) { |
535 | |
536 | are equivalent, but |
537 | |
538 | sub ((GET + .html) | (POST + .html)) { |
539 | |
540 | and |
541 | |
542 | sub (GET + .html | POST + .html) { |
543 | |
544 | are not - the latter is equivalent to |
545 | |
546 | sub (GET + (.html|POST) + .html) { |
547 | |
548 | which will never match. |
549 | |
550 | =head3 Whitespace |
15dfe701 |
551 | |
552 | Note that for legibility you are permitted to use whitespace - |
553 | |
44db8e76 |
554 | sub (GET + /user/*) { |
15dfe701 |
555 | |
b8bd7bd1 |
556 | but it will be ignored. This is because the perl parser strips whitespace |
557 | from subroutine prototypes, so this is equivalent to |
558 | |
559 | sub (GET+/user/*) { |
15dfe701 |
560 | |
8c4ffad3 |
561 | =head1 CHANGES BETWEEN RELEASES |
562 | |
563 | =head2 Changes since Antiquated Perl |
564 | |
565 | =over 4 |
566 | |
567 | =item * filter_response renamed to response_filter |
568 | |
569 | This is a pure rename; a global search and replace should fix it. |
570 | |
571 | =item * dispatch [] changed to dispatch [] |
572 | |
573 | Simply changing |
574 | |
575 | dispatch [ sub(...) { ... }, ... ]; |
576 | |
577 | to |
578 | |
579 | dispatch { sub(...) { ... }, ... }; |
580 | |
581 | should work fine. |
582 | |
583 | =back |
584 | |
585 | =head1 COMMUNITY AND SUPPORT |
586 | |
587 | =head2 IRC channel |
588 | |
589 | irc.perl.org #web-simple |
590 | |
591 | =head2 No mailing list yet |
592 | |
593 | Because mst's non-work email is a bombsite so he'd never read it anyway. |
594 | |
595 | =head2 Git repository |
596 | |
597 | Gitweb is on http://git.shadowcat.co.uk/ and the clone URL is: |
598 | |
599 | git clone git://git.shadowcat.co.uk/catagits/Web-Simple.git |
600 | |
601 | =head1 AUTHOR |
602 | |
603 | Matt S. Trout <mst@shadowcat.co.uk> |
604 | |
605 | =head1 CONTRIBUTORS |
606 | |
607 | None required yet. Maybe this module is perfect (hahahahaha ...). |
608 | |
609 | =head1 COPYRIGHT |
610 | |
611 | Copyright (c) 2009 the Web::Simple L</AUTHOR> and L</CONTRIBUTORS> |
612 | as listed above. |
613 | |
614 | =head1 LICENSE |
615 | |
616 | This library is free software and may be distributed under the same terms |
617 | as perl itself. |
618 | |
3583ca04 |
619 | =cut |
7401408e |
620 | |
5c33dda5 |
621 | 1; |