Commit | Line | Data |
5c33dda5 |
1 | package Web::Simple; |
2 | |
8bd060f4 |
3 | use strictures 1; |
8c4ffad3 |
4 | use 5.008; |
8bd060f4 |
5 | use warnings::illegalproto (); |
8c4ffad3 |
6 | |
9ddb5734 |
7 | our $VERSION = '0.004'; |
5c33dda5 |
8 | |
44db8e76 |
9 | sub import { |
5c33dda5 |
10 | my ($class, $app_package) = @_; |
eb5f8074 |
11 | $class->_export_into($app_package||caller); |
445b3ea0 |
12 | eval "package $class; use Web::Dispatch::Wrapper; use Moo;"; |
13 | strictures->import; |
8bd060f4 |
14 | warnings::illegalproto->unimport; |
5c33dda5 |
15 | } |
16 | |
17 | sub _export_into { |
18 | my ($class, $app_package) = @_; |
19 | { |
20 | no strict 'refs'; |
c7b1c57f |
21 | *{"${app_package}::PSGI_ENV"} = sub () { -1 }; |
5c33dda5 |
22 | require Web::Simple::Application; |
23 | unshift(@{"${app_package}::ISA"}, 'Web::Simple::Application'); |
24 | } |
b7063124 |
25 | (my $name = $app_package) =~ s/::/\//g; |
26 | $INC{"${name}.pm"} = 'Set by "use Web::Simple;" invocation'; |
5c33dda5 |
27 | } |
28 | |
7401408e |
29 | =head1 NAME |
30 | |
31 | Web::Simple - A quick and easy way to build simple web applications |
32 | |
33 | =head1 WARNING |
34 | |
8c4ffad3 |
35 | This is really quite new. If you're reading this on CPAN, it means the stuff |
36 | that's here we're probably happy with. But only probably. So we may have to |
37 | change stuff. And if you're reading this from git, come check with irc.perl.org |
38 | #web-simple that we're actually sure we're going to keep anything that's |
39 | different from the CPAN version. |
7401408e |
40 | |
8c4ffad3 |
41 | If we do find we have to change stuff we'll add to the |
42 | L<CHANGES BETWEEN RELEASES> section explaining how to switch your code across |
43 | to the new version, and we'll do our best to make it as painless as possible |
44 | because we've got Web::Simple applications too. But we can't promise not to |
45 | change things at all. Not yet. Sorry. |
7401408e |
46 | |
47 | =head1 SYNOPSIS |
48 | |
49 | #!/usr/bin/perl |
50 | |
51 | use Web::Simple 'HelloWorld'; |
52 | |
53 | { |
54 | package HelloWorld; |
55 | |
445b3ea0 |
56 | sub dispatch_request { |
7401408e |
57 | sub (GET) { |
58 | [ 200, [ 'Content-type', 'text/plain' ], [ 'Hello world!' ] ] |
59 | }, |
60 | sub () { |
61 | [ 405, [ 'Content-type', 'text/plain' ], [ 'Method not allowed' ] ] |
62 | } |
445b3ea0 |
63 | } |
7401408e |
64 | } |
65 | |
66 | HelloWorld->run_if_script; |
67 | |
68 | If you save this file into your cgi-bin as hello-world.cgi and then visit |
69 | |
70 | http://my.server.name/cgi-bin/hello-world.cgi/ |
71 | |
72 | you'll get the "Hello world!" string output to your browser. For more complex |
8c4ffad3 |
73 | examples and non-CGI deployment, see below. To get help with Web::Simple, |
74 | please connect to the irc.perl.org IRC network and join #web-simple. |
7401408e |
75 | |
76 | =head1 WHY? |
77 | |
da8429c9 |
78 | Web::Simple was originally written to form part of my Antiquated Perl talk for |
79 | Italian Perl Workshop 2009, but in writing the bloggery example I realised |
80 | that having a bare minimum system for writing web applications that doesn't |
81 | drive me insane was rather nice and decided to spend my attempt at nanowrimo |
82 | for 2009 improving and documenting it to the point where others could use it. |
7401408e |
83 | |
84 | The philosophy of Web::Simple is to keep to an absolute bare minimum, for |
85 | everything. It is not designed to be used for large scale applications; |
86 | the L<Catalyst> web framework already works very nicely for that and is |
87 | a far more mature, well supported piece of software. |
88 | |
89 | However, if you have an application that only does a couple of things, and |
90 | want to not have to think about complexities of deployment, then Web::Simple |
91 | might be just the thing for you. |
92 | |
93 | The Antiquated Perl talk can be found at L<http://www.shadowcat.co.uk/archive/conference-video/>. |
94 | |
95 | =head1 DESCRIPTION |
96 | |
97 | The only public interface the Web::Simple module itself provides is an |
98 | import based one - |
99 | |
100 | use Web::Simple 'NameOfApplication'; |
101 | |
102 | This imports 'strict' and 'warnings FATAL => "all"' into your code as well, |
103 | so you can skip the usual |
104 | |
105 | use strict; |
106 | use warnings; |
107 | |
108 | provided you 'use Web::Simple' at the top of the file. Note that we turn |
109 | on *fatal* warnings so if you have any warnings at any point from the file |
110 | that you did 'use Web::Simple' in, then your application will die. This is, |
111 | so far, considered a feature. |
112 | |
113 | Calling the import also makes NameOfApplication isa Web::Simple::Application |
445b3ea0 |
114 | and sets your app class up as a L<Moo> class- i.e. does the equivalent of |
7401408e |
115 | |
116 | { |
117 | package NameOfApplication; |
445b3ea0 |
118 | use Moo; |
119 | extends 'Web::Simple::Application'; |
7401408e |
120 | } |
121 | |
445b3ea0 |
122 | It also exports the following subroutines for use in dispatchers: |
7401408e |
123 | |
74afe4b7 |
124 | response_filter { ... }; |
7401408e |
125 | |
126 | redispatch_to '/somewhere'; |
127 | |
b7063124 |
128 | Finally, import sets |
129 | |
130 | $INC{"NameOfApplication.pm"} = 'Set by "use Web::Simple;" invocation'; |
131 | |
132 | so that perl will not attempt to load the application again even if |
133 | |
134 | require NameOfApplication; |
135 | |
136 | is encountered in other code. |
137 | |
3583ca04 |
138 | =head1 DISPATCH STRATEGY |
139 | |
c21c9f07 |
140 | =head2 Examples |
141 | |
445b3ea0 |
142 | sub dispatch_request { |
c21c9f07 |
143 | # matches: GET /user/1.htm?show_details=1 |
144 | # GET /user/1.htm |
145 | sub (GET + /user/* + ?show_details~ + .htm|.html|.xhtml) { |
c254b30e |
146 | my ($self, $user_id, $show_details) = @_; |
c21c9f07 |
147 | ... |
148 | }, |
149 | # matches: POST /user?username=frew |
150 | # POST /user?username=mst&first_name=matt&last_name=trout |
151 | sub (POST + /user + ?username=&*) { |
c254b30e |
152 | my ($self, $username, $misc_params) = @_; |
c21c9f07 |
153 | ... |
154 | }, |
155 | # matches: DELETE /user/1/friend/2 |
156 | sub (DELETE + /user/*/friend/*) { |
c254b30e |
157 | my ($self, $user_id, $friend_id) = @_; |
c21c9f07 |
158 | ... |
159 | }, |
160 | # matches: PUT /user/1?first_name=Matt&last_name=Trout |
161 | sub (PUT + /user/* + ?first_name~&last_name~) { |
c254b30e |
162 | my ($self, $user_id, $first_name, $last_name) = @_; |
c21c9f07 |
163 | ... |
164 | }, |
165 | sub (/user/*/...) { |
445b3ea0 |
166 | my $user_id = $_[1]; |
167 | # matches: PUT /user/1/role/1 |
168 | sub (PUT + /role/*) { |
169 | my $role_id = $_[1]; |
170 | ... |
171 | }, |
172 | # matches: DELETE /user/1/role/1 |
173 | sub (DELETE + /role/*) { |
174 | my $role_id = $_[1]; |
175 | ... |
176 | }, |
c21c9f07 |
177 | }, |
178 | } |
179 | |
445b3ea0 |
180 | =head2 |
181 | Description of the dispatcher object |
81a5b03e |
182 | |
183 | Web::Simple::Dispatcher objects have three components: |
184 | |
185 | =over 4 |
186 | |
187 | =item * match - an optional test if this dispatcher matches the request |
188 | |
189 | =item * call - a routine to call if this dispatcher matches (or has no match) |
190 | |
191 | =item * next - the next dispatcher to call |
192 | |
193 | =back |
194 | |
195 | When a dispatcher is invoked, it checks its match routine against the |
196 | request environment. The match routine may provide alterations to the |
197 | request as a result of matching, and/or arguments for the call routine. |
198 | |
199 | If no match routine has been provided then Web::Simple treats this as |
200 | a success, and supplies the request environment to the call routine as |
201 | an argument. |
202 | |
203 | Given a successful match, the call routine is now invoked in list context |
204 | with any arguments given to the original dispatch, plus any arguments |
205 | provided by the match result. |
206 | |
207 | If this routine returns (), Web::Simple treats this identically to a failure |
208 | to match. |
209 | |
210 | If this routine returns a Web::Simple::Dispatcher, the environment changes |
211 | are merged into the environment and the new dispatcher's next pointer is |
212 | set to our next pointer. |
213 | |
214 | If this routine returns anything else, that is treated as the end of dispatch |
215 | and the value is returned. |
216 | |
217 | On a failed match, Web::Simple invokes the next dispatcher with the same |
218 | arguments and request environment passed to the current one. On a successful |
219 | match that returned a new dispatcher, Web::Simple invokes the new dispatcher |
220 | with the same arguments but the modified request environment. |
221 | |
222 | =head2 How Web::Simple builds dispatcher objects for you |
223 | |
224 | In the case of the Web::Simple L</dispatch> export the match is constructed |
225 | from the subroutine prototype - i.e. |
226 | |
227 | sub (<match specification>) { |
228 | <call code> |
229 | } |
230 | |
231 | and the 'next' pointer is populated with the next element of the array, |
232 | expect for the last element, which is given a next that will throw a 500 |
233 | error if none of your dispatchers match. If you want to provide something |
234 | else as a default, a routine with no match specification always matches, so - |
235 | |
236 | sub () { |
237 | [ 404, [ 'Content-type', 'text/plain' ], [ 'Error: Not Found' ] ] |
238 | } |
239 | |
240 | will produce a 404 result instead of a 500 by default. You can also override |
241 | the L<Web::Simple::Application/_build_final_dispatcher> method in your app. |
242 | |
243 | Note that the code in the subroutine is executed as a -method- on your |
244 | application object, so if your match specification provides arguments you |
245 | should unpack them like so: |
246 | |
247 | sub (<match specification>) { |
248 | my ($self, @args) = @_; |
249 | ... |
250 | } |
251 | |
252 | =head2 Web::Simple match specifications |
253 | |
254 | =head3 Method matches |
255 | |
93e30ba3 |
256 | sub (GET) { |
15dfe701 |
257 | |
258 | A match specification beginning with a capital letter matches HTTP requests |
259 | with that request method. |
260 | |
81a5b03e |
261 | =head3 Path matches |
262 | |
15dfe701 |
263 | sub (/login) { |
264 | |
265 | A match specification beginning with a / is a path match. In the simplest |
266 | case it matches a specific path. To match a path with a wildcard part, you |
267 | can do: |
268 | |
269 | sub (/user/*) { |
270 | $self->handle_user($_[1]) |
271 | |
272 | This will match /user/<anything> where <anything> does not include a literal |
273 | / character. The matched part becomes part of the match arguments. You can |
274 | also match more than one part: |
275 | |
276 | sub (/user/*/*) { |
277 | my ($self, $user_1, $user_2) = @_; |
278 | |
279 | sub (/domain/*/user/*) { |
280 | my ($self, $domain, $user) = @_; |
281 | |
282 | and so on. To match an arbitrary number of parts, use - |
283 | |
284 | sub (/page/**) { |
285 | |
286 | This will result in an element per /-separated part so matched. Note that |
287 | you can do |
288 | |
289 | sub (/page/**/edit) { |
290 | |
291 | to match an arbitrary number of parts up to but not including some final |
292 | part. |
293 | |
da8429c9 |
294 | Finally, |
295 | |
296 | sub (/foo/...) { |
297 | |
298 | will match /foo/ on the beginning of the path -and- strip it, much like |
299 | .html strips the extension. This is designed to be used to construct |
300 | nested dispatch structures, but can also prove useful for having e.g. an |
301 | optional language specification at the start of a path. |
302 | |
303 | Note that the '...' is a "maybe something here, maybe not" so the above |
304 | specification will match like this: |
305 | |
306 | /foo # no match |
307 | /foo/ # match and strip path to '/' |
308 | /foo/bar/baz # match and strip path to '/bar/baz' |
309 | |
81a5b03e |
310 | =head3 Extension matches |
311 | |
15dfe701 |
312 | sub (.html) { |
313 | |
314 | will match and strip .html from the path (assuming the subroutine itself |
315 | returns something, of course). This is normally used for rendering - e.g. |
316 | |
317 | sub (.html) { |
74afe4b7 |
318 | response_filter { $self->render_html($_[1]) } |
15dfe701 |
319 | } |
320 | |
b8bd7bd1 |
321 | Additionally, |
322 | |
323 | sub (.*) { |
324 | |
325 | will match any extension and supplies the stripped extension as a match |
326 | argument. |
327 | |
9b9866ae |
328 | =head3 Query and body parameter matches |
329 | |
330 | Query and body parameters can be match via |
331 | |
332 | sub (?<param spec>) { # match URI query |
333 | sub (%<param spec>) { # match body params |
334 | |
335 | The body is only matched if the content type is |
336 | application/x-www-form-urlencoded (note this means that Web::Simple does |
337 | not yet handle uploads; this will be addressed in a later release). |
338 | |
339 | The param spec is elements of one of the following forms - |
340 | |
341 | param~ # optional parameter |
342 | param= # required parameter |
343 | @param~ # optional multiple parameter |
344 | @param= # required multiple parameter |
eb9e0e25 |
345 | :param~ # optional parameter in hashref |
346 | :param= # required parameter in hashref |
347 | :@param~ # optional multiple in hashref |
348 | :@param= # required multiple in hashref |
349 | * # include all other parameters in hashref |
350 | @* # include all other parameters as multiple in hashref |
9b9866ae |
351 | |
eb9e0e25 |
352 | separated by the & character. The arguments added to the request are |
353 | one per non-:/* parameter (scalar for normal, arrayref for multiple), |
354 | plus if any :/* specs exist a hashref containing those values. |
9b9866ae |
355 | |
356 | So, to match a page parameter with an optional order_by parameter one |
357 | would write: |
358 | |
359 | sub (?page=&order_by~) { |
eb9e0e25 |
360 | my ($self, $page, $order_by) = @_; |
361 | return unless $page =~ /^\d+$/; |
362 | $page ||= 'id'; |
9b9866ae |
363 | response_filter { |
364 | $_[1]->search_rs({}, $p); |
365 | } |
366 | } |
367 | |
368 | to implement paging and ordering against a L<DBIx::Class::ResultSet> object. |
369 | |
8c4ffad3 |
370 | Note that if a parameter is specified as single and multiple values are found, |
371 | the last one will be used. |
372 | |
eb9e0e25 |
373 | To get all parameters as a hashref of arrayrefs, write: |
374 | |
375 | sub(?@*) { |
376 | my ($self, $params) = @_; |
377 | ... |
378 | |
8c4ffad3 |
379 | To get two parameters as a hashref, write: |
380 | |
381 | sub(?:user~&:domain~) { |
382 | my ($self, $params) = @_; # params contains only 'user' and 'domain' keys |
383 | |
384 | You can also mix these, so: |
385 | |
386 | sub (?foo=&@bar~&:coffee=&@*) { |
387 | my ($self, $foo, $bar, $params); |
388 | |
389 | where $bar is an arrayref (possibly an empty one), and $params contains |
390 | arrayref values for all parameters -not- mentioned and a scalar value for |
391 | the 'coffee' parameter. |
392 | |
81a5b03e |
393 | =head3 Combining matches |
394 | |
15dfe701 |
395 | Matches may be combined with the + character - e.g. |
396 | |
b8bd7bd1 |
397 | sub (GET + /user/*) { |
398 | |
399 | to create an AND match. They may also be combined withe the | character - e.g. |
400 | |
401 | sub (GET|POST) { |
402 | |
403 | to create an OR match. Matches can be nested with () - e.g. |
404 | |
405 | sub ((GET|POST) + /user/*) { |
406 | |
407 | and negated with ! - e.g. |
408 | |
409 | sub (!/user/foo + /user/*) { |
410 | |
411 | ! binds to the immediate rightmost match specification, so if you want |
412 | to negate a combination you will need to use |
413 | |
414 | sub ( !(POST|PUT|DELETE) ) { |
415 | |
416 | and | binds tighter than +, so |
417 | |
418 | sub ((GET|POST) + /user/*) { |
419 | |
420 | and |
421 | |
422 | sub (GET|POST + /user/*) { |
423 | |
424 | are equivalent, but |
425 | |
426 | sub ((GET + .html) | (POST + .html)) { |
427 | |
428 | and |
429 | |
430 | sub (GET + .html | POST + .html) { |
431 | |
432 | are not - the latter is equivalent to |
433 | |
434 | sub (GET + (.html|POST) + .html) { |
435 | |
436 | which will never match. |
437 | |
438 | =head3 Whitespace |
15dfe701 |
439 | |
440 | Note that for legibility you are permitted to use whitespace - |
441 | |
44db8e76 |
442 | sub (GET + /user/*) { |
15dfe701 |
443 | |
b8bd7bd1 |
444 | but it will be ignored. This is because the perl parser strips whitespace |
445 | from subroutine prototypes, so this is equivalent to |
446 | |
447 | sub (GET+/user/*) { |
15dfe701 |
448 | |
24175cb5 |
449 | =head3 Accessing the PSGI env hash |
450 | |
451 | To gain the benefit of using some middleware, specifically |
452 | Plack::Middleware::Session access to the ENV hash is needed. This is provided |
453 | in arguments to the dispatched handler. You can access this hash with the |
445b3ea0 |
454 | exported PSGI_ENV constant. |
24175cb5 |
455 | |
456 | sub (GET + /foo + ?some_param=) { |
445b3ea0 |
457 | my($self, $some_param, $env) = @_[0, 1, PSGI_ENV]; |
c21c9f07 |
458 | |
445b3ea0 |
459 | =head2 Dispatcher return values |
c21c9f07 |
460 | |
445b3ea0 |
461 | A dispatcher returns one of: |
c21c9f07 |
462 | |
445b3ea0 |
463 | =head1 EXPORTED SUBROUTINES |
c21c9f07 |
464 | |
465 | =head2 response_filter |
466 | |
467 | response_filter { |
468 | # Hide errors from the user because we hates them, preciousss |
445b3ea0 |
469 | if (ref($_[0]) eq 'ARRAY' && $_[0]->[0] == 500) { |
470 | $_[0] = [ 200, @{$_[0]}[1..$#{$_[0]}] ]; |
c21c9f07 |
471 | } |
445b3ea0 |
472 | return $_[0]; |
c21c9f07 |
473 | }; |
474 | |
475 | The response_filter subroutine is designed for use inside dispatch subroutines. |
476 | |
477 | It creates and returns a special dispatcher that always matches, and calls |
478 | the block passed to it as a filter on the result of running the rest of the |
479 | current dispatch chain. |
480 | |
481 | Thus the filter above runs further dispatch as normal, but if the result of |
482 | dispatch is a 500 (Internal Server Error) response, changes this to a 200 (OK) |
483 | response without altering the headers or body. |
484 | |
485 | =head2 redispatch_to |
486 | |
487 | redispatch_to '/other/url'; |
488 | |
489 | The redispatch_to subroutine is designed for use inside dispatch subroutines. |
490 | |
491 | It creates and returns a special dispatcher that always matches, and instead |
492 | of continuing dispatch re-delegates it to the start of the dispatch process, |
493 | but with the path of the request altered to the supplied URL. |
494 | |
950d8829 |
495 | Thus if you receive a POST to '/some/url' and return a redispatch to |
c21c9f07 |
496 | '/other/url', the dispatch behaviour will be exactly as if the same POST |
497 | request had been made to '/other/url' instead. |
498 | |
499 | =head2 subdispatch |
500 | |
501 | subdispatch sub (/user/*/) { |
502 | my $u = $self->user($_[1]); |
503 | [ |
504 | sub (GET) { $u }, |
505 | sub (DELETE) { $u->delete }, |
506 | ] |
507 | } |
508 | |
509 | The subdispatch subroutine is designed for use in dispatcher construction. |
510 | |
511 | It creates a dispatcher which, if it matches, treats its return value not |
512 | as a final value but an arrayref of dispatch specifications such as could |
513 | be passed to the dispatch subroutine itself. These are turned into a dispatcher |
514 | which is then invoked. Any changes the match makes to the request are in |
515 | scope for this inner dispatcher only - so if the initial match is a |
516 | destructive one like .html the full path will be restored if the |
517 | subdispatch fails. |
518 | |
8c4ffad3 |
519 | =head1 CHANGES BETWEEN RELEASES |
445b3ea0 |
520 | |
521 | =head2 Changes between 0.004 and 0.005 |
522 | |
523 | =over 4 |
524 | |
525 | =item * dispatch {} replaced by declaring a dispatch_request method |
526 | |
527 | dispatch {} has gone away - instead, you write: |
528 | |
529 | sub dispatch_request { |
e4122532 |
530 | my $self = shift; |
445b3ea0 |
531 | sub (GET /foo/) { ... }, |
532 | ... |
533 | } |
534 | |
535 | Note that this method is still -returning- the dispatch code - just like |
536 | dispatch did. |
537 | |
e4122532 |
538 | Also note that you need the 'my $self = shift' since the magic $self |
539 | variable went away. |
540 | |
541 | =item * the magic $self variable went away. |
542 | |
543 | Just add 'my $self = shift;' while writing your 'sub dispatch_request {' |
544 | like a normal perl method. |
545 | |
445b3ea0 |
546 | =item * subdispatch deleted - all dispatchers can now subdispatch |
547 | |
548 | In earlier releases you needed to write: |
549 | |
550 | subdispatch sub (/foo/...) { |
551 | ... |
552 | [ |
553 | sub (GET /bar/) { ... }, |
554 | ... |
555 | ] |
556 | } |
557 | |
558 | As of 0.005, you can instead write simply: |
559 | |
560 | sub (/foo/...) { |
561 | ... |
562 | ( |
563 | sub (GET /bar/) { ... }, |
564 | ... |
565 | ) |
566 | } |
8c4ffad3 |
567 | |
568 | =head2 Changes since Antiquated Perl |
569 | |
570 | =over 4 |
571 | |
572 | =item * filter_response renamed to response_filter |
573 | |
574 | This is a pure rename; a global search and replace should fix it. |
575 | |
c21c9f07 |
576 | =item * dispatch [] changed to dispatch {} |
8c4ffad3 |
577 | |
578 | Simply changing |
579 | |
580 | dispatch [ sub(...) { ... }, ... ]; |
581 | |
582 | to |
583 | |
584 | dispatch { sub(...) { ... }, ... }; |
585 | |
586 | should work fine. |
587 | |
588 | =back |
589 | |
590 | =head1 COMMUNITY AND SUPPORT |
591 | |
592 | =head2 IRC channel |
593 | |
594 | irc.perl.org #web-simple |
595 | |
596 | =head2 No mailing list yet |
597 | |
598 | Because mst's non-work email is a bombsite so he'd never read it anyway. |
599 | |
600 | =head2 Git repository |
601 | |
602 | Gitweb is on http://git.shadowcat.co.uk/ and the clone URL is: |
603 | |
604 | git clone git://git.shadowcat.co.uk/catagits/Web-Simple.git |
605 | |
606 | =head1 AUTHOR |
607 | |
608 | Matt S. Trout <mst@shadowcat.co.uk> |
609 | |
610 | =head1 CONTRIBUTORS |
611 | |
612 | None required yet. Maybe this module is perfect (hahahahaha ...). |
613 | |
614 | =head1 COPYRIGHT |
615 | |
616 | Copyright (c) 2009 the Web::Simple L</AUTHOR> and L</CONTRIBUTORS> |
617 | as listed above. |
618 | |
619 | =head1 LICENSE |
620 | |
621 | This library is free software and may be distributed under the same terms |
622 | as perl itself. |
623 | |
3583ca04 |
624 | =cut |
7401408e |
625 | |
5c33dda5 |
626 | 1; |