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) { |
1c34f703 |
250 | if (my $capture_attr = $action->attributes->{CaptureArgs}) { |
a82c96cf |
251 | my $capture_count = $action->number_of_captures|| 0; |
f505df49 |
252 | |
253 | # Short-circuit if not enough remaining parts |
3f91cb25 |
254 | next TRY_ACTION unless @parts >= $capture_count; |
f505df49 |
255 | |
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256 | my @captures; |
257 | my @parts = @parts; # localise |
7a7ac23c |
258 | |
1c34f703 |
259 | # strip CaptureArgs into list |
3f91cb25 |
260 | push(@captures, splice(@parts, 0, $capture_count)); |
7a7ac23c |
261 | |
1279064a |
262 | # check if the action may fit, depending on a given test by the app |
a82c96cf |
263 | next TRY_ACTION unless $action->match_captures($c, \@captures); |
1279064a |
264 | |
141459fa |
265 | # try the remaining parts against children of this action |
0c78acb6 |
266 | my ($actions, $captures, $action_parts, $n_pathparts) = $self->recurse_match( |
141459fa |
267 | $c, '/'.$action->reverse, \@parts |
268 | ); |
2f381252 |
269 | # No best action currently |
270 | # OR The action has less parts |
271 | # OR The action has equal parts but less captured data (ergo more defined) |
272 | if ($actions && |
273 | (!$best_action || |
f4dbb497 |
274 | $#$action_parts < $#{$best_action->{parts}} || |
2f381252 |
275 | ($#$action_parts == $#{$best_action->{parts}} && |
0c78acb6 |
276 | $#$captures < $#{$best_action->{captures}} && |
277 | $n_pathparts > $best_action->{n_pathparts}))) { |
278 | my @pathparts = split /\//, $action->attributes->{PathPart}->[0]; |
6b495723 |
279 | $best_action = { |
280 | actions => [ $action, @$actions ], |
281 | captures=> [ @captures, @$captures ], |
0c78acb6 |
282 | parts => $action_parts, |
283 | n_pathparts => scalar(@pathparts) + $n_pathparts, |
284 | }; |
6b495723 |
285 | } |
286 | } |
287 | else { |
7a7ac23c |
288 | { |
289 | local $c->req->{arguments} = [ @{$c->req->args}, @parts ]; |
290 | next TRY_ACTION unless $action->match($c); |
291 | } |
5c6d829d |
292 | my $args_attr = $action->attributes->{Args}->[0]; |
2a1c08c0 |
293 | my $args_count = $action->normalized_arg_number; |
0c78acb6 |
294 | my @pathparts = split /\//, $action->attributes->{PathPart}->[0]; |
953c176d |
295 | # No best action currently |
296 | # OR This one matches with fewer parts left than the current best action, |
297 | # And therefore is a better match |
b0ad47c1 |
298 | # OR No parts and this expects 0 |
953c176d |
299 | # The current best action might also be Args(0), |
300 | # but we couldn't chose between then anyway so we'll take the last seen |
301 | |
219b4f88 |
302 | if ( |
303 | !$best_action || |
953c176d |
304 | @parts < @{$best_action->{parts}} || |
219b4f88 |
305 | ( |
306 | !@parts && |
307 | defined($args_attr) && |
09914a47 |
308 | ( |
2a1c08c0 |
309 | $args_count eq "0" && |
7a504990 |
310 | ( |
311 | ($c->config->{use_chained_args_0_special_case}||0) || |
312 | ( |
2a1c08c0 |
313 | exists($best_action->{args_count}) && defined($best_action->{args_count}) ? |
314 | ($best_action->{args_count} ne 0) : 1 |
7a504990 |
315 | ) |
316 | ) |
09914a47 |
317 | ) |
219b4f88 |
318 | ) |
319 | ){ |
6b495723 |
320 | $best_action = { |
321 | actions => [ $action ], |
322 | captures=> [], |
0c78acb6 |
323 | parts => \@parts, |
2a1c08c0 |
324 | args_count => $args_count, |
0c78acb6 |
325 | n_pathparts => scalar(@pathparts), |
326 | }; |
953c176d |
327 | } |
141459fa |
328 | } |
329 | } |
330 | } |
0c78acb6 |
331 | return @$best_action{qw/actions captures parts n_pathparts/} if $best_action; |
141459fa |
332 | return (); |
333 | } |
334 | |
335 | =head2 $self->register( $c, $action ) |
336 | |
05a90578 |
337 | Calls register_path for every Path attribute for the given $action. |
141459fa |
338 | |
339 | =cut |
340 | |
341 | sub register { |
342 | my ( $self, $c, $action ) = @_; |
343 | |
1dc8af44 |
344 | my @chained_attr = @{ $action->attributes->{Chained} || [] }; |
141459fa |
345 | |
1dc8af44 |
346 | return 0 unless @chained_attr; |
141459fa |
347 | |
2f381252 |
348 | if (@chained_attr > 1) { |
141459fa |
349 | Catalyst::Exception->throw( |
5882c86e |
350 | "Multiple Chained attributes not supported registering ${action}" |
141459fa |
351 | ); |
352 | } |
13c6b4cc |
353 | my $chained_to = $chained_attr[0]; |
141459fa |
354 | |
13c6b4cc |
355 | Catalyst::Exception->throw( |
356 | "Actions cannot chain to themselves registering /${action}" |
357 | ) if ($chained_to eq '/' . $action); |
358 | |
359 | my $children = ($self->_children_of->{ $chained_to } ||= {}); |
141459fa |
360 | |
361 | my @path_part = @{ $action->attributes->{PathPart} || [] }; |
362 | |
09461385 |
363 | my $part = $action->name; |
141459fa |
364 | |
09461385 |
365 | if (@path_part == 1 && defined $path_part[0]) { |
366 | $part = $path_part[0]; |
141459fa |
367 | } elsif (@path_part > 1) { |
368 | Catalyst::Exception->throw( |
f3414019 |
369 | "Multiple PathPart attributes not supported registering " . $action->reverse() |
141459fa |
370 | ); |
371 | } |
372 | |
8a6a6581 |
373 | if ($part =~ m(^/)) { |
374 | Catalyst::Exception->throw( |
f3414019 |
375 | "Absolute parameters to PathPart not allowed registering " . $action->reverse() |
8a6a6581 |
376 | ); |
377 | } |
378 | |
0ca510f0 |
379 | my $encoded_part = URI->new($part)->canonical; |
380 | $encoded_part =~ s{(?<=[^/])/+\z}{}; |
792b40ac |
381 | |
0ca510f0 |
382 | $action->attributes->{PathPart} = [ $encoded_part ]; |
383 | |
384 | unshift(@{ $children->{$encoded_part} ||= [] }, $action); |
141459fa |
385 | |
be5cb4e4 |
386 | $self->_actions->{'/'.$action->reverse} = $action; |
792b40ac |
387 | |
2e29aec2 |
388 | if (exists $action->attributes->{Args} and exists $action->attributes->{CaptureArgs}) { |
389 | Catalyst::Exception->throw( |
bc71493a |
390 | "Combining Args and CaptureArgs attributes not supported registering " . |
391 | $action->reverse() |
2e29aec2 |
392 | ); |
dd97c1ac |
393 | } |
394 | |
1c34f703 |
395 | unless ($action->attributes->{CaptureArgs}) { |
be5cb4e4 |
396 | unshift(@{ $self->_endpoints }, $action); |
792b40ac |
397 | } |
398 | |
399 | return 1; |
141459fa |
400 | } |
401 | |
402 | =head2 $self->uri_for_action($action, $captures) |
403 | |
05a90578 |
404 | Get the URI part for the action, using C<$captures> to fill |
405 | the capturing parts. |
141459fa |
406 | |
407 | =cut |
408 | |
409 | sub uri_for_action { |
410 | my ( $self, $action, $captures ) = @_; |
411 | |
5882c86e |
412 | return undef unless ($action->attributes->{Chained} |
8b13f357 |
413 | && !$action->attributes->{CaptureArgs}); |
792b40ac |
414 | |
415 | my @parts = (); |
416 | my @captures = @$captures; |
417 | my $parent = "DUMMY"; |
418 | my $curr = $action; |
b6847871 |
419 | # If this is an action chain get the last action in the chain |
420 | if($curr->can('chain') ) { |
421 | $curr = ${$curr->chain}[-1]; |
422 | } |
792b40ac |
423 | while ($curr) { |
b6847871 |
424 | if (my $cap = $curr->number_of_captures) { |
425 | return undef unless @captures >= $cap; # not enough captures |
426 | if ($cap) { |
427 | unshift(@parts, splice(@captures, -$cap)); |
8b13f357 |
428 | } |
792b40ac |
429 | } |
77771155 |
430 | if (my $pp = $curr->attributes->{PathPart}) { |
792b40ac |
431 | unshift(@parts, $pp->[0]) |
8b13f357 |
432 | if (defined($pp->[0]) && length($pp->[0])); |
792b40ac |
433 | } |
5882c86e |
434 | $parent = $curr->attributes->{Chained}->[0]; |
be5cb4e4 |
435 | $curr = $self->_actions->{$parent}; |
141459fa |
436 | } |
792b40ac |
437 | |
438 | return undef unless $parent eq '/'; # fail for dangling action |
439 | |
440 | return undef if @captures; # fail for too many captures |
441 | |
442 | return join('/', '', @parts); |
59d5a638 |
443 | |
141459fa |
444 | } |
445 | |
ae0e35ee |
446 | =head2 $c->expand_action($action) |
447 | |
b0ad47c1 |
448 | Return a list of actions that represents a chained action. See |
ae0e35ee |
449 | L<Catalyst::Dispatcher> for more info. You probably want to |
450 | use the expand_action it provides rather than this directly. |
451 | |
452 | =cut |
453 | |
52f71256 |
454 | sub expand_action { |
455 | my ($self, $action) = @_; |
456 | |
457 | return unless $action->attributes && $action->attributes->{Chained}; |
458 | |
459 | my @chain; |
460 | my $curr = $action; |
461 | |
462 | while ($curr) { |
463 | push @chain, $curr; |
464 | my $parent = $curr->attributes->{Chained}->[0]; |
465 | $curr = $self->_actions->{$parent}; |
466 | } |
467 | |
468 | return Catalyst::ActionChain->from_chain([reverse @chain]); |
469 | } |
470 | |
e5ecd5bc |
471 | __PACKAGE__->meta->make_immutable; |
f4de8c99 |
472 | 1; |
e5ecd5bc |
473 | |
05a90578 |
474 | =head1 USAGE |
475 | |
476 | =head2 Introduction |
477 | |
478 | The C<Chained> attribute allows you to chain public path parts together |
67869327 |
479 | by their private names. A chain part's path can be specified with |
480 | C<PathPart> and can be declared to expect an arbitrary number of |
481 | arguments. The endpoint of the chain specifies how many arguments it |
482 | gets through the C<Args> attribute. C<:Args(0)> would be none at all, |
483 | C<:Args> without an integer would be unlimited. The path parts that |
484 | aren't endpoints are using C<CaptureArgs> to specify how many parameters |
485 | they expect to receive. As an example setup: |
05a90578 |
486 | |
487 | package MyApp::Controller::Greeting; |
488 | use base qw/ Catalyst::Controller /; |
489 | |
490 | # this is the beginning of our chain |
491 | sub hello : PathPart('hello') Chained('/') CaptureArgs(1) { |
492 | my ( $self, $c, $integer ) = @_; |
493 | $c->stash->{ message } = "Hello "; |
494 | $c->stash->{ arg_sum } = $integer; |
495 | } |
496 | |
497 | # this is our endpoint, because it has no :CaptureArgs |
498 | sub world : PathPart('world') Chained('hello') Args(1) { |
499 | my ( $self, $c, $integer ) = @_; |
500 | $c->stash->{ message } .= "World!"; |
501 | $c->stash->{ arg_sum } += $integer; |
502 | |
503 | $c->response->body( join "<br/>\n" => |
504 | $c->stash->{ message }, $c->stash->{ arg_sum } ); |
505 | } |
506 | |
507 | The debug output provides a separate table for chained actions, showing |
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508 | the whole chain as it would match and the actions it contains. Here's an |
509 | example of the startup output with our actions above: |
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510 | |
511 | ... |
512 | [debug] Loaded Path Part actions: |
513 | .-----------------------+------------------------------. |
514 | | Path Spec | Private | |
515 | +-----------------------+------------------------------+ |
516 | | /hello/*/world/* | /greeting/hello (1) | |
517 | | | => /greeting/world | |
518 | '-----------------------+------------------------------' |
519 | ... |
520 | |
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521 | As you can see, Catalyst only deals with chains as whole paths and |
522 | builds one for each endpoint, which are the actions with C<:Chained> but |
523 | without C<:CaptureArgs>. |
05a90578 |
524 | |
525 | Let's assume this application gets a request at the path |
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526 | C</hello/23/world/12>. What happens then? First, Catalyst will dispatch |
527 | to the C<hello> action and pass the value C<23> as an argument to it |
528 | after the context. It does so because we have previously used |
529 | C<:CaptureArgs(1)> to declare that it has one path part after itself as |
530 | its argument. We told Catalyst that this is the beginning of the chain |
531 | by specifying C<:Chained('/')>. Also note that instead of saying |
532 | C<:PathPart('hello')> we could also just have said C<:PathPart>, as it |
533 | defaults to the name of the action. |
05a90578 |
534 | |
535 | After C<hello> has run, Catalyst goes on to dispatch to the C<world> |
67869327 |
536 | action. This is the last action to be called: Catalyst knows this is an |
537 | endpoint because we did not specify a C<:CaptureArgs> |
538 | attribute. Nevertheless we specify that this action expects an argument, |
539 | but at this point we're using C<:Args(1)> to do that. We could also have |
540 | said C<:Args> or left it out altogether, which would mean this action |
541 | would get all arguments that are there. This action's C<:Chained> |
542 | attribute says C<hello> and tells Catalyst that the C<hello> action in |
543 | the current controller is its parent. |
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544 | |
545 | With this we have built a chain consisting of two public path parts. |
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546 | C<hello> captures one part of the path as its argument, and also |
547 | specifies the path root as its parent. So this part is |
548 | C</hello/$arg>. The next part is the endpoint C<world>, expecting one |
549 | argument. It sums up to the path part C<world/$arg>. This leads to a |
550 | complete chain of C</hello/$arg/world/$arg> which is matched against the |
551 | requested paths. |
552 | |
553 | This example application would, if run and called by e.g. |
554 | C</hello/23/world/12>, set the stash value C<message> to "Hello" and the |
555 | value C<arg_sum> to "23". The C<world> action would then append "World!" |
556 | to C<message> and add C<12> to the stash's C<arg_sum> value. For the |
557 | sake of simplicity no view is shown. Instead we just put the values of |
558 | the stash into our body. So the output would look like: |
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559 | |
560 | Hello World! |
561 | 35 |
562 | |
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563 | And our test server would have given us this debugging output for the |
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564 | request: |
565 | |
566 | ... |
567 | [debug] "GET" request for "hello/23/world/12" from "127.0.0.1" |
568 | [debug] Path is "/greeting/world" |
569 | [debug] Arguments are "12" |
570 | [info] Request took 0.164113s (6.093/s) |
571 | .------------------------------------------+-----------. |
572 | | Action | Time | |
573 | +------------------------------------------+-----------+ |
574 | | /greeting/hello | 0.000029s | |
575 | | /greeting/world | 0.000024s | |
576 | '------------------------------------------+-----------' |
577 | ... |
578 | |
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579 | What would be common uses of this dispatch technique? It gives the |
580 | possibility to split up logic that contains steps that each depend on |
581 | each other. An example would be, for example, a wiki path like |
05a90578 |
582 | C</wiki/FooBarPage/rev/23/view>. This chain can be easily built with |
583 | these actions: |
584 | |
585 | sub wiki : PathPart('wiki') Chained('/') CaptureArgs(1) { |
586 | my ( $self, $c, $page_name ) = @_; |
587 | # load the page named $page_name and put the object |
588 | # into the stash |
589 | } |
590 | |
591 | sub rev : PathPart('rev') Chained('wiki') CaptureArgs(1) { |
592 | my ( $self, $c, $revision_id ) = @_; |
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593 | # use the page object in the stash to get at its |
05a90578 |
594 | # revision with number $revision_id |
595 | } |
596 | |
597 | sub view : PathPart Chained('rev') Args(0) { |
598 | my ( $self, $c ) = @_; |
67869327 |
599 | # display the revision in our stash. Another option |
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600 | # would be to forward a compatible object to the action |
601 | # that displays the default wiki pages, unless we want |
602 | # a different interface here, for example restore |
603 | # functionality. |
604 | } |
605 | |
67869327 |
606 | It would now be possible to add other endpoints, for example C<restore> |
607 | to restore this specific revision as the current state. |
05a90578 |
608 | |
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609 | You don't have to put all the chained actions in one controller. The |
610 | specification of the parent through C<:Chained> also takes an absolute |
611 | action path as its argument. Just specify it with a leading C</>. |
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612 | |
613 | If you want, for example, to have actions for the public paths |
67869327 |
614 | C</foo/12/edit> and C</foo/12>, just specify two actions with |
05a90578 |
615 | C<:PathPart('foo')> and C<:Chained('/')>. The handler for the former |
67869327 |
616 | path needs a C<:CaptureArgs(1)> attribute and a endpoint with |
05a90578 |
617 | C<:PathPart('edit')> and C<:Chained('foo')>. For the latter path give |
618 | the action just a C<:Args(1)> to mark it as endpoint. This sums up to |
619 | this debugging output: |
620 | |
621 | ... |
622 | [debug] Loaded Path Part actions: |
623 | .-----------------------+------------------------------. |
624 | | Path Spec | Private | |
625 | +-----------------------+------------------------------+ |
626 | | /foo/* | /controller/foo_view | |
627 | | /foo/*/edit | /controller/foo_load (1) | |
628 | | | => /controller/edit | |
629 | '-----------------------+------------------------------' |
630 | ... |
631 | |
b0ad47c1 |
632 | Here's a more detailed specification of the attributes belonging to |
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633 | C<:Chained>: |
634 | |
635 | =head2 Attributes |
636 | |
637 | =over 8 |
638 | |
639 | =item PathPart |
640 | |
641 | Sets the name of this part of the chain. If it is specified without |
642 | arguments, it takes the name of the action as default. So basically |
643 | C<sub foo :PathPart> and C<sub foo :PathPart('foo')> are identical. |
644 | This can also contain slashes to bind to a deeper level. An action |
645 | with C<sub bar :PathPart('foo/bar') :Chained('/')> would bind to |
646 | C</foo/bar/...>. If you don't specify C<:PathPart> it has the same |
647 | effect as using C<:PathPart>, it would default to the action name. |
648 | |
d21a2b27 |
649 | =item PathPrefix |
650 | |
651 | Sets PathPart to the path_prefix of the current controller. |
652 | |
05a90578 |
653 | =item Chained |
654 | |
655 | Has to be specified for every child in the chain. Possible values are |
d21a2b27 |
656 | absolute and relative private action paths or a single slash C</> to |
657 | tell Catalyst that this is the root of a chain. The attribute |
658 | C<:Chained> without arguments also defaults to the C</> behavior. |
659 | Relative action paths may use C<../> to refer to actions in parent |
660 | controllers. |
05a90578 |
661 | |
67869327 |
662 | Because you can specify an absolute path to the parent action, it |
663 | doesn't matter to Catalyst where that parent is located. So, if your |
664 | design requests it, you can redispatch a chain through any controller or |
665 | namespace you want. |
05a90578 |
666 | |
667 | Another interesting possibility gives C<:Chained('.')>, which chains |
67869327 |
668 | itself to an action with the path of the current controller's namespace. |
05a90578 |
669 | For example: |
670 | |
671 | # in MyApp::Controller::Foo |
672 | sub bar : Chained CaptureArgs(1) { ... } |
673 | |
674 | # in MyApp::Controller::Foo::Bar |
675 | sub baz : Chained('.') Args(1) { ... } |
676 | |
677 | This builds up a chain like C</bar/*/baz/*>. The specification of C<.> |
67869327 |
678 | as the argument to Chained here chains the C<baz> action to an action |
679 | with the path of the current controller namespace, namely |
680 | C</foo/bar>. That action chains directly to C</>, so the C</bar/*/baz/*> |
681 | chain comes out as the end product. |
05a90578 |
682 | |
d21a2b27 |
683 | =item ChainedParent |
684 | |
685 | Chains an action to another action with the same name in the parent |
686 | controller. For Example: |
687 | |
688 | # in MyApp::Controller::Foo |
689 | sub bar : Chained CaptureArgs(1) { ... } |
690 | |
691 | # in MyApp::Controller::Foo::Moo |
692 | sub bar : ChainedParent Args(1) { ... } |
693 | |
694 | This builds a chain like C</bar/*/bar/*>. |
695 | |
05a90578 |
696 | =item CaptureArgs |
697 | |
67869327 |
698 | Must be specified for every part of the chain that is not an |
05a90578 |
699 | endpoint. With this attribute Catalyst knows how many of the following |
67869327 |
700 | parts of the path (separated by C</>) this action wants to capture as |
701 | its arguments. If it doesn't expect any, just specify |
702 | C<:CaptureArgs(0)>. The captures get passed to the action's C<@_> right |
703 | after the context, but you can also find them as array references in |
05a90578 |
704 | C<$c-E<gt>request-E<gt>captures-E<gt>[$level]>. The C<$level> is the |
705 | level of the action in the chain that captured the parts of the path. |
706 | |
67869327 |
707 | An action that is part of a chain (that is, one that has a C<:Chained> |
708 | attribute) but has no C<:CaptureArgs> attribute is treated by Catalyst |
709 | as a chain end. |
05a90578 |
710 | |
480d94b5 |
711 | Allowed values for CaptureArgs is a single integer (CaptureArgs(2), meaning two |
712 | allowed) or you can declare a L<Moose>, L<MooseX::Types> or L<Type::Tiny> |
713 | named constraint such as CaptureArgs(Int,Str) would require two args with |
714 | the first being a Integer and the second a string. You may declare your own |
715 | custom type constraints and import them into the controller namespace: |
716 | |
717 | package MyApp::Controller::Root; |
718 | |
719 | use Moose; |
720 | use MooseX::MethodAttributes; |
721 | use MyApp::Types qw/Int/; |
722 | |
723 | extends 'Catalyst::Controller'; |
724 | |
725 | sub chain_base :Chained(/) CaptureArgs(1) { } |
726 | |
727 | sub any_priority_chain :Chained(chain_base) PathPart('') Args(1) { } |
728 | |
729 | sub int_priority_chain :Chained(chain_base) PathPart('') Args(Int) { } |
730 | |
731 | See L<Catalyst::RouteMatching> for more. |
732 | |
05a90578 |
733 | =item Args |
734 | |
735 | By default, endpoints receive the rest of the arguments in the path. You |
736 | can tell Catalyst through C<:Args> explicitly how many arguments your |
737 | endpoint expects, just like you can with C<:CaptureArgs>. Note that this |
67869327 |
738 | also affects whether this chain is invoked on a request. A chain with an |
05a90578 |
739 | endpoint specifying one argument will only match if exactly one argument |
740 | exists in the path. |
741 | |
742 | You can specify an exact number of arguments like C<:Args(3)>, including |
743 | C<0>. If you just say C<:Args> without any arguments, it is the same as |
67869327 |
744 | leaving it out altogether: The chain is matched regardless of the number |
05a90578 |
745 | of path parts after the endpoint. |
746 | |
67869327 |
747 | Just as with C<:CaptureArgs>, the arguments get passed to the action in |
05a90578 |
748 | C<@_> after the context object. They can also be reached through |
749 | C<$c-E<gt>request-E<gt>arguments>. |
750 | |
751 | =back |
752 | |
67869327 |
753 | =head2 Auto actions, dispatching and forwarding |
05a90578 |
754 | |
755 | Note that the list of C<auto> actions called depends on the private path |
67869327 |
756 | of the endpoint of the chain, not on the chained actions way. The |
757 | C<auto> actions will be run before the chain dispatching begins. In |
758 | every other aspect, C<auto> actions behave as documented. |
05a90578 |
759 | |
64111aca |
760 | The C<forward>ing to other actions does just what you would expect. i.e. |
e1207438 |
761 | only the target action is run. The actions that that action is chained |
762 | to are not run. |
763 | If you C<detach> out of a chain, the rest of the chain will not get |
764 | called after the C<detach>. |
05a90578 |
765 | |
22faeff5 |
766 | =head2 match_captures |
767 | |
768 | A method which can optionally be implemented by actions to |
769 | stop chain matching. |
770 | |
771 | See L<Catalyst::Action> for further details. |
772 | |
2f381252 |
773 | =head1 AUTHORS |
141459fa |
774 | |
2f381252 |
775 | Catalyst Contributors, see Catalyst.pm |
141459fa |
776 | |
777 | =head1 COPYRIGHT |
778 | |
536bee89 |
779 | This library is free software. You can redistribute it and/or modify it under |
141459fa |
780 | the same terms as Perl itself. |
781 | |
782 | =cut |
783 | |
784 | 1; |