Commit | Line | Data |
5882c86e |
1 | package Catalyst::DispatchType::Chained; |
141459fa |
2 | |
3c0186f2 |
3 | use Moose; |
e8b9f2a9 |
4 | extends 'Catalyst::DispatchType'; |
5 | |
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6 | use Text::SimpleTable; |
7 | use Catalyst::ActionChain; |
39fc2ce1 |
8 | use Catalyst::Utils; |
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9 | use URI; |
dd97c1ac |
10 | use Scalar::Util (); |
0ca510f0 |
11 | use Encode 2.21 'decode_utf8'; |
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12 | |
be5cb4e4 |
13 | has _endpoints => ( |
14 | is => 'rw', |
15 | isa => 'ArrayRef', |
16 | required => 1, |
17 | default => sub{ [] }, |
18 | ); |
19 | |
20 | has _actions => ( |
21 | is => 'rw', |
22 | isa => 'HashRef', |
23 | required => 1, |
24 | default => sub{ {} }, |
25 | ); |
26 | |
27 | has _children_of => ( |
28 | is => 'rw', |
29 | isa => 'HashRef', |
30 | required => 1, |
31 | default => sub{ {} }, |
32 | ); |
33 | |
0fc2d522 |
34 | no Moose; |
35 | |
792b40ac |
36 | # please don't perltidy this. hairy code within. |
37 | |
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38 | =head1 NAME |
39 | |
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40 | Catalyst::DispatchType::Chained - Path Part DispatchType |
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41 | |
42 | =head1 SYNOPSIS |
43 | |
26dc649a |
44 | Path part matching, allowing several actions to sequentially take care of processing a request: |
45 | |
05a90578 |
46 | # root action - captures one argument after it |
47 | sub foo_setup : Chained('/') PathPart('foo') CaptureArgs(1) { |
48 | my ( $self, $c, $foo_arg ) = @_; |
49 | ... |
50 | } |
51 | |
52 | # child action endpoint - takes one argument |
53 | sub bar : Chained('foo_setup') Args(1) { |
54 | my ( $self, $c, $bar_arg ) = @_; |
55 | ... |
56 | } |
141459fa |
57 | |
58 | =head1 DESCRIPTION |
59 | |
26dc649a |
60 | Dispatch type managing default behaviour. For more information on |
61 | dispatch types, see: |
62 | |
63 | =over 4 |
64 | |
b9b89145 |
65 | =item * L<Catalyst::Manual::Intro> for how they affect application authors |
26dc649a |
66 | |
67 | =item * L<Catalyst::DispatchType> for implementation information. |
68 | |
69 | =back |
05a90578 |
70 | |
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71 | =head1 METHODS |
72 | |
73 | =head2 $self->list($c) |
74 | |
75 | Debug output for Path Part dispatch points |
76 | |
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77 | =cut |
78 | |
792b40ac |
79 | sub list { |
80 | my ( $self, $c ) = @_; |
81 | |
be5cb4e4 |
82 | return unless $self->_endpoints; |
792b40ac |
83 | |
48d435ba |
84 | my $avail_width = Catalyst::Utils::term_width() - 9; |
85 | my $col1_width = ($avail_width * .50) < 35 ? 35 : int($avail_width * .50); |
86 | my $col2_width = $avail_width - $col1_width; |
792b40ac |
87 | my $paths = Text::SimpleTable->new( |
48d435ba |
88 | [ $col1_width, 'Path Spec' ], [ $col2_width, 'Private' ], |
39fc2ce1 |
89 | ); |
792b40ac |
90 | |
007a7ca0 |
91 | my $has_unattached_actions; |
92 | my $unattached_actions = Text::SimpleTable->new( |
48d435ba |
93 | [ $col1_width, 'Private' ], [ $col2_width, 'Missing parent' ], |
007a7ca0 |
94 | ); |
95 | |
792b40ac |
96 | ENDPOINT: foreach my $endpoint ( |
97 | sort { $a->reverse cmp $b->reverse } |
be5cb4e4 |
98 | @{ $self->_endpoints } |
792b40ac |
99 | ) { |
ffca3e96 |
100 | my $args = $endpoint->list_extra_info->{Args}; |
79b7db20 |
101 | my @parts = (defined($endpoint->attributes->{Args}[0]) ? (("*") x $args) : '...'); |
d34667c3 |
102 | my @parents = (); |
792b40ac |
103 | my $parent = "DUMMY"; |
ba3f8a81 |
104 | my $extra = $self->_list_extra_http_methods($endpoint); |
e72a3cd6 |
105 | my $consumes = $self->_list_extra_consumes($endpoint); |
342d2169 |
106 | my $scheme = $self->_list_extra_scheme($endpoint); |
792b40ac |
107 | my $curr = $endpoint; |
108 | while ($curr) { |
ffca3e96 |
109 | if (my $cap = $curr->list_extra_info->{CaptureArgs}) { |
110 | unshift(@parts, (("*") x $cap)); |
792b40ac |
111 | } |
77771155 |
112 | if (my $pp = $curr->attributes->{PathPart}) { |
792b40ac |
113 | unshift(@parts, $pp->[0]) |
114 | if (defined $pp->[0] && length $pp->[0]); |
115 | } |
5882c86e |
116 | $parent = $curr->attributes->{Chained}->[0]; |
be5cb4e4 |
117 | $curr = $self->_actions->{$parent}; |
d34667c3 |
118 | unshift(@parents, $curr) if $curr; |
792b40ac |
119 | } |
007a7ca0 |
120 | if ($parent ne '/') { |
121 | $has_unattached_actions = 1; |
59d5a638 |
122 | $unattached_actions->row('/' . ($parents[0] || $endpoint)->reverse, $parent); |
007a7ca0 |
123 | next ENDPOINT; |
124 | } |
d34667c3 |
125 | my @rows; |
126 | foreach my $p (@parents) { |
127 | my $name = "/${p}"; |
ba3f8a81 |
128 | |
129 | if (defined(my $extra = $self->_list_extra_http_methods($p))) { |
130 | $name = "${extra} ${name}"; |
131 | } |
ffca3e96 |
132 | if (defined(my $cap = $p->list_extra_info->{CaptureArgs})) { |
90102012 |
133 | if($p->has_captures_constraints) { |
134 | my $tc = join ',', @{$p->captures_constraints}; |
135 | $name .= " ($tc)"; |
136 | } else { |
137 | $name .= " ($cap)"; |
138 | } |
d34667c3 |
139 | } |
e72a3cd6 |
140 | if (defined(my $ct = $p->list_extra_info->{Consumes})) { |
141 | $name .= ' :'.$ct; |
142 | } |
342d2169 |
143 | if (defined(my $s = $p->list_extra_info->{Scheme})) { |
144 | $scheme = uc $s; |
145 | } |
e72a3cd6 |
146 | |
d34667c3 |
147 | unless ($p eq $parents[0]) { |
148 | $name = "-> ${name}"; |
149 | } |
150 | push(@rows, [ '', $name ]); |
151 | } |
90102012 |
152 | |
79b7db20 |
153 | if($endpoint->has_args_constraints) { |
154 | my $tc = join ',', @{$endpoint->args_constraints}; |
155 | $endpoint .= " ($tc)"; |
156 | } else { |
157 | $endpoint .= defined($endpoint->attributes->{Args}[0]) ? " ($args)" : " (...)"; |
90102012 |
158 | } |
342d2169 |
159 | push(@rows, [ '', (@rows ? "=> " : '').($extra ? "$extra " : ''). ($scheme ? "$scheme: ":'')."/${endpoint}". ($consumes ? " :$consumes":"" ) ]); |
0ca510f0 |
160 | my @display_parts = map { $_ =~s/%([0-9A-Fa-f]{2})/chr(hex($1))/eg; decode_utf8 $_ } @parts; |
161 | $rows[0][0] = join('/', '', @display_parts) || '/'; |
d34667c3 |
162 | $paths->row(@$_) for @rows; |
792b40ac |
163 | } |
164 | |
1cf0345b |
165 | $c->log->debug( "Loaded Chained actions:\n" . $paths->draw . "\n" ); |
007a7ca0 |
166 | $c->log->debug( "Unattached Chained actions:\n", $unattached_actions->draw . "\n" ) |
167 | if $has_unattached_actions; |
792b40ac |
168 | } |
141459fa |
169 | |
ba3f8a81 |
170 | sub _list_extra_http_methods { |
171 | my ( $self, $action ) = @_; |
172 | return unless defined $action->list_extra_info->{HTTP_METHODS}; |
173 | return join(', ', @{$action->list_extra_info->{HTTP_METHODS}}); |
e72a3cd6 |
174 | |
ba3f8a81 |
175 | } |
176 | |
e72a3cd6 |
177 | sub _list_extra_consumes { |
178 | my ( $self, $action ) = @_; |
179 | return unless defined $action->list_extra_info->{CONSUMES}; |
180 | return join(', ', @{$action->list_extra_info->{CONSUMES}}); |
181 | } |
182 | |
342d2169 |
183 | sub _list_extra_scheme { |
184 | my ( $self, $action ) = @_; |
185 | return unless defined $action->list_extra_info->{Scheme}; |
186 | return uc $action->list_extra_info->{Scheme}; |
187 | } |
e72a3cd6 |
188 | |
141459fa |
189 | =head2 $self->match( $c, $path ) |
190 | |
05a90578 |
191 | Calls C<recurse_match> to see if a chain matches the C<$path>. |
141459fa |
192 | |
193 | =cut |
194 | |
195 | sub match { |
196 | my ( $self, $c, $path ) = @_; |
197 | |
e5ecd5bc |
198 | my $request = $c->request; |
199 | return 0 if @{$request->args}; |
141459fa |
200 | |
201 | my @parts = split('/', $path); |
202 | |
6365b527 |
203 | my ($chain, $captures, $parts) = $self->recurse_match($c, '/', \@parts); |
634780e0 |
204 | |
205 | if ($parts && @$parts) { |
206 | for my $arg (@$parts) { |
207 | $arg =~ s/%([0-9A-Fa-f]{2})/chr(hex($1))/eg; |
208 | push @{$request->args}, $arg; |
209 | } |
210 | } |
141459fa |
211 | |
212 | return 0 unless $chain; |
213 | |
214 | my $action = Catalyst::ActionChain->from_chain($chain); |
215 | |
e5ecd5bc |
216 | $request->action("/${action}"); |
217 | $request->match("/${action}"); |
218 | $request->captures($captures); |
141459fa |
219 | $c->action($action); |
220 | $c->namespace( $action->namespace ); |
221 | |
222 | return 1; |
223 | } |
224 | |
225 | =head2 $self->recurse_match( $c, $parent, \@path_parts ) |
226 | |
05a90578 |
227 | Recursive search for a matching chain. |
141459fa |
228 | |
229 | =cut |
230 | |
231 | sub recurse_match { |
232 | my ( $self, $c, $parent, $path_parts ) = @_; |
be5cb4e4 |
233 | my $children = $self->_children_of->{$parent}; |
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234 | return () unless $children; |
6b495723 |
235 | my $best_action; |
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236 | my @captures; |
1b04b972 |
237 | TRY: foreach my $try_part (sort { length($b) <=> length($a) } |
cdc97b63 |
238 | keys %$children) { |
1b04b972 |
239 | # $b then $a to try longest part first |
141459fa |
240 | my @parts = @$path_parts; |
241 | if (length $try_part) { # test and strip PathPart |
242 | next TRY unless |
243 | ($try_part eq join('/', # assemble equal number of parts |
244 | splice( # and strip them off @parts as well |
792b40ac |
245 | @parts, 0, scalar(@{[split('/', $try_part)]}) |
246 | ))); # @{[]} to avoid split to @_ |
141459fa |
247 | } |
248 | my @try_actions = @{$children->{$try_part}}; |
249 | TRY_ACTION: foreach my $action (@try_actions) { |
905679b8 |
250 | |
251 | |
1c34f703 |
252 | if (my $capture_attr = $action->attributes->{CaptureArgs}) { |
a82c96cf |
253 | my $capture_count = $action->number_of_captures|| 0; |
f505df49 |
254 | |
255 | # Short-circuit if not enough remaining parts |
3f91cb25 |
256 | next TRY_ACTION unless @parts >= $capture_count; |
f505df49 |
257 | |
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258 | my @captures; |
259 | my @parts = @parts; # localise |
7a7ac23c |
260 | |
1c34f703 |
261 | # strip CaptureArgs into list |
3f91cb25 |
262 | push(@captures, splice(@parts, 0, $capture_count)); |
7a7ac23c |
263 | |
1279064a |
264 | # check if the action may fit, depending on a given test by the app |
a82c96cf |
265 | next TRY_ACTION unless $action->match_captures($c, \@captures); |
1279064a |
266 | |
141459fa |
267 | # try the remaining parts against children of this action |
0c78acb6 |
268 | my ($actions, $captures, $action_parts, $n_pathparts) = $self->recurse_match( |
141459fa |
269 | $c, '/'.$action->reverse, \@parts |
270 | ); |
2f381252 |
271 | # No best action currently |
272 | # OR The action has less parts |
273 | # OR The action has equal parts but less captured data (ergo more defined) |
274 | if ($actions && |
275 | (!$best_action || |
f4dbb497 |
276 | $#$action_parts < $#{$best_action->{parts}} || |
2f381252 |
277 | ($#$action_parts == $#{$best_action->{parts}} && |
0c78acb6 |
278 | $#$captures < $#{$best_action->{captures}} && |
279 | $n_pathparts > $best_action->{n_pathparts}))) { |
280 | my @pathparts = split /\//, $action->attributes->{PathPart}->[0]; |
6b495723 |
281 | $best_action = { |
282 | actions => [ $action, @$actions ], |
283 | captures=> [ @captures, @$captures ], |
0c78acb6 |
284 | parts => $action_parts, |
285 | n_pathparts => scalar(@pathparts) + $n_pathparts, |
286 | }; |
6b495723 |
287 | } |
288 | } |
289 | else { |
7a7ac23c |
290 | { |
291 | local $c->req->{arguments} = [ @{$c->req->args}, @parts ]; |
292 | next TRY_ACTION unless $action->match($c); |
293 | } |
5c6d829d |
294 | my $args_attr = $action->attributes->{Args}->[0]; |
2a1c08c0 |
295 | my $args_count = $action->normalized_arg_number; |
0c78acb6 |
296 | my @pathparts = split /\//, $action->attributes->{PathPart}->[0]; |
953c176d |
297 | # No best action currently |
298 | # OR This one matches with fewer parts left than the current best action, |
299 | # And therefore is a better match |
b0ad47c1 |
300 | # OR No parts and this expects 0 |
953c176d |
301 | # The current best action might also be Args(0), |
302 | # but we couldn't chose between then anyway so we'll take the last seen |
219b4f88 |
303 | if ( |
304 | !$best_action || |
953c176d |
305 | @parts < @{$best_action->{parts}} || |
219b4f88 |
306 | ( |
307 | !@parts && |
308 | defined($args_attr) && |
09914a47 |
309 | ( |
2a1c08c0 |
310 | $args_count eq "0" && |
7a504990 |
311 | ( |
312 | ($c->config->{use_chained_args_0_special_case}||0) || |
313 | ( |
2a1c08c0 |
314 | exists($best_action->{args_count}) && defined($best_action->{args_count}) ? |
315 | ($best_action->{args_count} ne 0) : 1 |
7a504990 |
316 | ) |
317 | ) |
09914a47 |
318 | ) |
219b4f88 |
319 | ) |
320 | ){ |
6b495723 |
321 | $best_action = { |
322 | actions => [ $action ], |
323 | captures=> [], |
0c78acb6 |
324 | parts => \@parts, |
2a1c08c0 |
325 | args_count => $args_count, |
0c78acb6 |
326 | n_pathparts => scalar(@pathparts), |
327 | }; |
953c176d |
328 | } |
141459fa |
329 | } |
330 | } |
331 | } |
0c78acb6 |
332 | return @$best_action{qw/actions captures parts n_pathparts/} if $best_action; |
141459fa |
333 | return (); |
334 | } |
335 | |
336 | =head2 $self->register( $c, $action ) |
337 | |
05a90578 |
338 | Calls register_path for every Path attribute for the given $action. |
141459fa |
339 | |
340 | =cut |
341 | |
342 | sub register { |
343 | my ( $self, $c, $action ) = @_; |
344 | |
1dc8af44 |
345 | my @chained_attr = @{ $action->attributes->{Chained} || [] }; |
141459fa |
346 | |
1dc8af44 |
347 | return 0 unless @chained_attr; |
141459fa |
348 | |
2f381252 |
349 | if (@chained_attr > 1) { |
141459fa |
350 | Catalyst::Exception->throw( |
5882c86e |
351 | "Multiple Chained attributes not supported registering ${action}" |
141459fa |
352 | ); |
353 | } |
13c6b4cc |
354 | my $chained_to = $chained_attr[0]; |
141459fa |
355 | |
13c6b4cc |
356 | Catalyst::Exception->throw( |
357 | "Actions cannot chain to themselves registering /${action}" |
358 | ) if ($chained_to eq '/' . $action); |
359 | |
360 | my $children = ($self->_children_of->{ $chained_to } ||= {}); |
141459fa |
361 | |
362 | my @path_part = @{ $action->attributes->{PathPart} || [] }; |
363 | |
09461385 |
364 | my $part = $action->name; |
141459fa |
365 | |
09461385 |
366 | if (@path_part == 1 && defined $path_part[0]) { |
367 | $part = $path_part[0]; |
141459fa |
368 | } elsif (@path_part > 1) { |
369 | Catalyst::Exception->throw( |
f3414019 |
370 | "Multiple PathPart attributes not supported registering " . $action->reverse() |
141459fa |
371 | ); |
372 | } |
373 | |
8a6a6581 |
374 | if ($part =~ m(^/)) { |
375 | Catalyst::Exception->throw( |
f3414019 |
376 | "Absolute parameters to PathPart not allowed registering " . $action->reverse() |
8a6a6581 |
377 | ); |
378 | } |
379 | |
0ca510f0 |
380 | my $encoded_part = URI->new($part)->canonical; |
381 | $encoded_part =~ s{(?<=[^/])/+\z}{}; |
792b40ac |
382 | |
0ca510f0 |
383 | $action->attributes->{PathPart} = [ $encoded_part ]; |
384 | |
385 | unshift(@{ $children->{$encoded_part} ||= [] }, $action); |
141459fa |
386 | |
be5cb4e4 |
387 | $self->_actions->{'/'.$action->reverse} = $action; |
792b40ac |
388 | |
2e29aec2 |
389 | if (exists $action->attributes->{Args} and exists $action->attributes->{CaptureArgs}) { |
390 | Catalyst::Exception->throw( |
bc71493a |
391 | "Combining Args and CaptureArgs attributes not supported registering " . |
392 | $action->reverse() |
2e29aec2 |
393 | ); |
dd97c1ac |
394 | } |
395 | |
1c34f703 |
396 | unless ($action->attributes->{CaptureArgs}) { |
be5cb4e4 |
397 | unshift(@{ $self->_endpoints }, $action); |
792b40ac |
398 | } |
399 | |
400 | return 1; |
141459fa |
401 | } |
402 | |
403 | =head2 $self->uri_for_action($action, $captures) |
404 | |
05a90578 |
405 | Get the URI part for the action, using C<$captures> to fill |
406 | the capturing parts. |
141459fa |
407 | |
408 | =cut |
409 | |
410 | sub uri_for_action { |
411 | my ( $self, $action, $captures ) = @_; |
412 | |
5882c86e |
413 | return undef unless ($action->attributes->{Chained} |
8b13f357 |
414 | && !$action->attributes->{CaptureArgs}); |
792b40ac |
415 | |
416 | my @parts = (); |
417 | my @captures = @$captures; |
418 | my $parent = "DUMMY"; |
419 | my $curr = $action; |
b6847871 |
420 | # If this is an action chain get the last action in the chain |
421 | if($curr->can('chain') ) { |
422 | $curr = ${$curr->chain}[-1]; |
423 | } |
792b40ac |
424 | while ($curr) { |
b6847871 |
425 | if (my $cap = $curr->number_of_captures) { |
426 | return undef unless @captures >= $cap; # not enough captures |
427 | if ($cap) { |
428 | unshift(@parts, splice(@captures, -$cap)); |
8b13f357 |
429 | } |
792b40ac |
430 | } |
77771155 |
431 | if (my $pp = $curr->attributes->{PathPart}) { |
792b40ac |
432 | unshift(@parts, $pp->[0]) |
8b13f357 |
433 | if (defined($pp->[0]) && length($pp->[0])); |
792b40ac |
434 | } |
5882c86e |
435 | $parent = $curr->attributes->{Chained}->[0]; |
be5cb4e4 |
436 | $curr = $self->_actions->{$parent}; |
141459fa |
437 | } |
792b40ac |
438 | |
439 | return undef unless $parent eq '/'; # fail for dangling action |
440 | |
441 | return undef if @captures; # fail for too many captures |
442 | |
443 | return join('/', '', @parts); |
59d5a638 |
444 | |
141459fa |
445 | } |
446 | |
ae0e35ee |
447 | =head2 $c->expand_action($action) |
448 | |
b0ad47c1 |
449 | Return a list of actions that represents a chained action. See |
ae0e35ee |
450 | L<Catalyst::Dispatcher> for more info. You probably want to |
451 | use the expand_action it provides rather than this directly. |
452 | |
453 | =cut |
454 | |
52f71256 |
455 | sub expand_action { |
456 | my ($self, $action) = @_; |
457 | |
458 | return unless $action->attributes && $action->attributes->{Chained}; |
459 | |
460 | my @chain; |
461 | my $curr = $action; |
462 | |
463 | while ($curr) { |
464 | push @chain, $curr; |
465 | my $parent = $curr->attributes->{Chained}->[0]; |
466 | $curr = $self->_actions->{$parent}; |
467 | } |
468 | |
469 | return Catalyst::ActionChain->from_chain([reverse @chain]); |
470 | } |
471 | |
e5ecd5bc |
472 | __PACKAGE__->meta->make_immutable; |
f4de8c99 |
473 | 1; |
e5ecd5bc |
474 | |
05a90578 |
475 | =head1 USAGE |
476 | |
477 | =head2 Introduction |
478 | |
479 | The C<Chained> attribute allows you to chain public path parts together |
67869327 |
480 | by their private names. A chain part's path can be specified with |
481 | C<PathPart> and can be declared to expect an arbitrary number of |
482 | arguments. The endpoint of the chain specifies how many arguments it |
483 | gets through the C<Args> attribute. C<:Args(0)> would be none at all, |
484 | C<:Args> without an integer would be unlimited. The path parts that |
485 | aren't endpoints are using C<CaptureArgs> to specify how many parameters |
486 | they expect to receive. As an example setup: |
05a90578 |
487 | |
488 | package MyApp::Controller::Greeting; |
489 | use base qw/ Catalyst::Controller /; |
490 | |
491 | # this is the beginning of our chain |
492 | sub hello : PathPart('hello') Chained('/') CaptureArgs(1) { |
493 | my ( $self, $c, $integer ) = @_; |
494 | $c->stash->{ message } = "Hello "; |
495 | $c->stash->{ arg_sum } = $integer; |
496 | } |
497 | |
498 | # this is our endpoint, because it has no :CaptureArgs |
499 | sub world : PathPart('world') Chained('hello') Args(1) { |
500 | my ( $self, $c, $integer ) = @_; |
501 | $c->stash->{ message } .= "World!"; |
502 | $c->stash->{ arg_sum } += $integer; |
503 | |
504 | $c->response->body( join "<br/>\n" => |
505 | $c->stash->{ message }, $c->stash->{ arg_sum } ); |
506 | } |
507 | |
508 | The debug output provides a separate table for chained actions, showing |
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509 | the whole chain as it would match and the actions it contains. Here's an |
510 | example of the startup output with our actions above: |
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511 | |
512 | ... |
513 | [debug] Loaded Path Part actions: |
514 | .-----------------------+------------------------------. |
515 | | Path Spec | Private | |
516 | +-----------------------+------------------------------+ |
517 | | /hello/*/world/* | /greeting/hello (1) | |
518 | | | => /greeting/world | |
519 | '-----------------------+------------------------------' |
520 | ... |
521 | |
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522 | As you can see, Catalyst only deals with chains as whole paths and |
523 | builds one for each endpoint, which are the actions with C<:Chained> but |
524 | without C<:CaptureArgs>. |
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525 | |
526 | Let's assume this application gets a request at the path |
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527 | C</hello/23/world/12>. What happens then? First, Catalyst will dispatch |
528 | to the C<hello> action and pass the value C<23> as an argument to it |
529 | after the context. It does so because we have previously used |
530 | C<:CaptureArgs(1)> to declare that it has one path part after itself as |
531 | its argument. We told Catalyst that this is the beginning of the chain |
532 | by specifying C<:Chained('/')>. Also note that instead of saying |
533 | C<:PathPart('hello')> we could also just have said C<:PathPart>, as it |
534 | defaults to the name of the action. |
05a90578 |
535 | |
536 | After C<hello> has run, Catalyst goes on to dispatch to the C<world> |
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537 | action. This is the last action to be called: Catalyst knows this is an |
538 | endpoint because we did not specify a C<:CaptureArgs> |
539 | attribute. Nevertheless we specify that this action expects an argument, |
540 | but at this point we're using C<:Args(1)> to do that. We could also have |
541 | said C<:Args> or left it out altogether, which would mean this action |
542 | would get all arguments that are there. This action's C<:Chained> |
543 | attribute says C<hello> and tells Catalyst that the C<hello> action in |
544 | the current controller is its parent. |
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545 | |
546 | With this we have built a chain consisting of two public path parts. |
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547 | C<hello> captures one part of the path as its argument, and also |
548 | specifies the path root as its parent. So this part is |
549 | C</hello/$arg>. The next part is the endpoint C<world>, expecting one |
550 | argument. It sums up to the path part C<world/$arg>. This leads to a |
551 | complete chain of C</hello/$arg/world/$arg> which is matched against the |
552 | requested paths. |
553 | |
554 | This example application would, if run and called by e.g. |
555 | C</hello/23/world/12>, set the stash value C<message> to "Hello" and the |
556 | value C<arg_sum> to "23". The C<world> action would then append "World!" |
557 | to C<message> and add C<12> to the stash's C<arg_sum> value. For the |
558 | sake of simplicity no view is shown. Instead we just put the values of |
559 | the stash into our body. So the output would look like: |
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560 | |
561 | Hello World! |
562 | 35 |
563 | |
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564 | And our test server would have given us this debugging output for the |
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565 | request: |
566 | |
567 | ... |
568 | [debug] "GET" request for "hello/23/world/12" from "127.0.0.1" |
569 | [debug] Path is "/greeting/world" |
570 | [debug] Arguments are "12" |
571 | [info] Request took 0.164113s (6.093/s) |
572 | .------------------------------------------+-----------. |
573 | | Action | Time | |
574 | +------------------------------------------+-----------+ |
575 | | /greeting/hello | 0.000029s | |
576 | | /greeting/world | 0.000024s | |
577 | '------------------------------------------+-----------' |
578 | ... |
579 | |
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580 | What would be common uses of this dispatch technique? It gives the |
581 | possibility to split up logic that contains steps that each depend on |
582 | each other. An example would be, for example, a wiki path like |
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583 | C</wiki/FooBarPage/rev/23/view>. This chain can be easily built with |
584 | these actions: |
585 | |
586 | sub wiki : PathPart('wiki') Chained('/') CaptureArgs(1) { |
587 | my ( $self, $c, $page_name ) = @_; |
588 | # load the page named $page_name and put the object |
589 | # into the stash |
590 | } |
591 | |
592 | sub rev : PathPart('rev') Chained('wiki') CaptureArgs(1) { |
593 | my ( $self, $c, $revision_id ) = @_; |
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594 | # use the page object in the stash to get at its |
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595 | # revision with number $revision_id |
596 | } |
597 | |
598 | sub view : PathPart Chained('rev') Args(0) { |
599 | my ( $self, $c ) = @_; |
67869327 |
600 | # display the revision in our stash. Another option |
05a90578 |
601 | # would be to forward a compatible object to the action |
602 | # that displays the default wiki pages, unless we want |
603 | # a different interface here, for example restore |
604 | # functionality. |
605 | } |
606 | |
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607 | It would now be possible to add other endpoints, for example C<restore> |
608 | to restore this specific revision as the current state. |
05a90578 |
609 | |
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610 | You don't have to put all the chained actions in one controller. The |
611 | specification of the parent through C<:Chained> also takes an absolute |
612 | action path as its argument. Just specify it with a leading C</>. |
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613 | |
614 | If you want, for example, to have actions for the public paths |
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615 | C</foo/12/edit> and C</foo/12>, just specify two actions with |
05a90578 |
616 | C<:PathPart('foo')> and C<:Chained('/')>. The handler for the former |
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617 | path needs a C<:CaptureArgs(1)> attribute and a endpoint with |
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618 | C<:PathPart('edit')> and C<:Chained('foo')>. For the latter path give |
619 | the action just a C<:Args(1)> to mark it as endpoint. This sums up to |
620 | this debugging output: |
621 | |
622 | ... |
623 | [debug] Loaded Path Part actions: |
624 | .-----------------------+------------------------------. |
625 | | Path Spec | Private | |
626 | +-----------------------+------------------------------+ |
627 | | /foo/* | /controller/foo_view | |
628 | | /foo/*/edit | /controller/foo_load (1) | |
629 | | | => /controller/edit | |
630 | '-----------------------+------------------------------' |
631 | ... |
632 | |
b0ad47c1 |
633 | Here's a more detailed specification of the attributes belonging to |
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634 | C<:Chained>: |
635 | |
636 | =head2 Attributes |
637 | |
638 | =over 8 |
639 | |
640 | =item PathPart |
641 | |
642 | Sets the name of this part of the chain. If it is specified without |
643 | arguments, it takes the name of the action as default. So basically |
644 | C<sub foo :PathPart> and C<sub foo :PathPart('foo')> are identical. |
645 | This can also contain slashes to bind to a deeper level. An action |
646 | with C<sub bar :PathPart('foo/bar') :Chained('/')> would bind to |
647 | C</foo/bar/...>. If you don't specify C<:PathPart> it has the same |
648 | effect as using C<:PathPart>, it would default to the action name. |
649 | |
d21a2b27 |
650 | =item PathPrefix |
651 | |
652 | Sets PathPart to the path_prefix of the current controller. |
653 | |
05a90578 |
654 | =item Chained |
655 | |
656 | Has to be specified for every child in the chain. Possible values are |
d21a2b27 |
657 | absolute and relative private action paths or a single slash C</> to |
658 | tell Catalyst that this is the root of a chain. The attribute |
659 | C<:Chained> without arguments also defaults to the C</> behavior. |
660 | Relative action paths may use C<../> to refer to actions in parent |
661 | controllers. |
05a90578 |
662 | |
67869327 |
663 | Because you can specify an absolute path to the parent action, it |
664 | doesn't matter to Catalyst where that parent is located. So, if your |
665 | design requests it, you can redispatch a chain through any controller or |
666 | namespace you want. |
05a90578 |
667 | |
668 | Another interesting possibility gives C<:Chained('.')>, which chains |
67869327 |
669 | itself to an action with the path of the current controller's namespace. |
05a90578 |
670 | For example: |
671 | |
672 | # in MyApp::Controller::Foo |
673 | sub bar : Chained CaptureArgs(1) { ... } |
674 | |
675 | # in MyApp::Controller::Foo::Bar |
676 | sub baz : Chained('.') Args(1) { ... } |
677 | |
678 | This builds up a chain like C</bar/*/baz/*>. The specification of C<.> |
67869327 |
679 | as the argument to Chained here chains the C<baz> action to an action |
680 | with the path of the current controller namespace, namely |
681 | C</foo/bar>. That action chains directly to C</>, so the C</bar/*/baz/*> |
682 | chain comes out as the end product. |
05a90578 |
683 | |
d21a2b27 |
684 | =item ChainedParent |
685 | |
686 | Chains an action to another action with the same name in the parent |
687 | controller. For Example: |
688 | |
689 | # in MyApp::Controller::Foo |
690 | sub bar : Chained CaptureArgs(1) { ... } |
691 | |
692 | # in MyApp::Controller::Foo::Moo |
693 | sub bar : ChainedParent Args(1) { ... } |
694 | |
695 | This builds a chain like C</bar/*/bar/*>. |
696 | |
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697 | =item CaptureArgs |
698 | |
67869327 |
699 | Must be specified for every part of the chain that is not an |
05a90578 |
700 | endpoint. With this attribute Catalyst knows how many of the following |
67869327 |
701 | parts of the path (separated by C</>) this action wants to capture as |
702 | its arguments. If it doesn't expect any, just specify |
703 | C<:CaptureArgs(0)>. The captures get passed to the action's C<@_> right |
704 | after the context, but you can also find them as array references in |
05a90578 |
705 | C<$c-E<gt>request-E<gt>captures-E<gt>[$level]>. The C<$level> is the |
706 | level of the action in the chain that captured the parts of the path. |
707 | |
67869327 |
708 | An action that is part of a chain (that is, one that has a C<:Chained> |
709 | attribute) but has no C<:CaptureArgs> attribute is treated by Catalyst |
710 | as a chain end. |
05a90578 |
711 | |
480d94b5 |
712 | Allowed values for CaptureArgs is a single integer (CaptureArgs(2), meaning two |
713 | allowed) or you can declare a L<Moose>, L<MooseX::Types> or L<Type::Tiny> |
714 | named constraint such as CaptureArgs(Int,Str) would require two args with |
715 | the first being a Integer and the second a string. You may declare your own |
716 | custom type constraints and import them into the controller namespace: |
717 | |
718 | package MyApp::Controller::Root; |
719 | |
720 | use Moose; |
721 | use MooseX::MethodAttributes; |
722 | use MyApp::Types qw/Int/; |
723 | |
724 | extends 'Catalyst::Controller'; |
725 | |
726 | sub chain_base :Chained(/) CaptureArgs(1) { } |
727 | |
728 | sub any_priority_chain :Chained(chain_base) PathPart('') Args(1) { } |
729 | |
730 | sub int_priority_chain :Chained(chain_base) PathPart('') Args(Int) { } |
731 | |
d9f0a350 |
732 | If you use a reference type constraint in CaptureArgs, it must be a type |
733 | like Tuple in L<Types::Standard> that allows us to determine the number of |
734 | args to match. Otherwise this will raise an error during startup. |
735 | |
480d94b5 |
736 | See L<Catalyst::RouteMatching> for more. |
737 | |
05a90578 |
738 | =item Args |
739 | |
740 | By default, endpoints receive the rest of the arguments in the path. You |
741 | can tell Catalyst through C<:Args> explicitly how many arguments your |
742 | endpoint expects, just like you can with C<:CaptureArgs>. Note that this |
67869327 |
743 | also affects whether this chain is invoked on a request. A chain with an |
05a90578 |
744 | endpoint specifying one argument will only match if exactly one argument |
745 | exists in the path. |
746 | |
747 | You can specify an exact number of arguments like C<:Args(3)>, including |
748 | C<0>. If you just say C<:Args> without any arguments, it is the same as |
67869327 |
749 | leaving it out altogether: The chain is matched regardless of the number |
05a90578 |
750 | of path parts after the endpoint. |
751 | |
67869327 |
752 | Just as with C<:CaptureArgs>, the arguments get passed to the action in |
05a90578 |
753 | C<@_> after the context object. They can also be reached through |
754 | C<$c-E<gt>request-E<gt>arguments>. |
755 | |
d9f0a350 |
756 | You should see 'Args' in L<Catalyst::Controller> for more details on using |
757 | type constraints in your Args declarations. |
758 | |
05a90578 |
759 | =back |
760 | |
67869327 |
761 | =head2 Auto actions, dispatching and forwarding |
05a90578 |
762 | |
763 | Note that the list of C<auto> actions called depends on the private path |
67869327 |
764 | of the endpoint of the chain, not on the chained actions way. The |
765 | C<auto> actions will be run before the chain dispatching begins. In |
766 | every other aspect, C<auto> actions behave as documented. |
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767 | |
64111aca |
768 | The C<forward>ing to other actions does just what you would expect. i.e. |
e1207438 |
769 | only the target action is run. The actions that that action is chained |
770 | to are not run. |
771 | If you C<detach> out of a chain, the rest of the chain will not get |
772 | called after the C<detach>. |
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773 | |
22faeff5 |
774 | =head2 match_captures |
775 | |
776 | A method which can optionally be implemented by actions to |
777 | stop chain matching. |
778 | |
779 | See L<Catalyst::Action> for further details. |
780 | |
2f381252 |
781 | =head1 AUTHORS |
141459fa |
782 | |
2f381252 |
783 | Catalyst Contributors, see Catalyst.pm |
141459fa |
784 | |
785 | =head1 COPYRIGHT |
786 | |
536bee89 |
787 | This library is free software. You can redistribute it and/or modify it under |
141459fa |
788 | the same terms as Perl itself. |
789 | |
790 | =cut |
791 | |
792 | 1; |