Commit | Line | Data |
5882c86e |
1 | package Catalyst::DispatchType::Chained; |
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2 | |
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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 (); |
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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 | } |
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57 | |
58 | =head1 DESCRIPTION |
59 | |
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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 |
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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 | |
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96 | ENDPOINT: foreach my $endpoint ( |
97 | sort { $a->reverse cmp $b->reverse } |
be5cb4e4 |
98 | @{ $self->_endpoints } |
792b40ac |
99 | ) { |
ffca3e96 |
100 | my $args = $endpoint->list_extra_info->{Args}; |
792b40ac |
101 | my @parts = (defined($args) ? (("*") 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 | } |
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116 | $parent = $curr->attributes->{Chained}->[0]; |
be5cb4e4 |
117 | $curr = $self->_actions->{$parent}; |
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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})) { |
133 | $name .= ' ('.$cap.')'; |
d34667c3 |
134 | } |
e72a3cd6 |
135 | if (defined(my $ct = $p->list_extra_info->{Consumes})) { |
136 | $name .= ' :'.$ct; |
137 | } |
342d2169 |
138 | if (defined(my $s = $p->list_extra_info->{Scheme})) { |
139 | $scheme = uc $s; |
140 | } |
e72a3cd6 |
141 | |
d34667c3 |
142 | unless ($p eq $parents[0]) { |
143 | $name = "-> ${name}"; |
144 | } |
145 | push(@rows, [ '', $name ]); |
146 | } |
342d2169 |
147 | push(@rows, [ '', (@rows ? "=> " : '').($extra ? "$extra " : ''). ($scheme ? "$scheme: ":'')."/${endpoint}". ($consumes ? " :$consumes":"" ) ]); |
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148 | my @display_parts = map { $_ =~s/%([0-9A-Fa-f]{2})/chr(hex($1))/eg; decode_utf8 $_ } @parts; |
149 | $rows[0][0] = join('/', '', @display_parts) || '/'; |
d34667c3 |
150 | $paths->row(@$_) for @rows; |
792b40ac |
151 | } |
152 | |
1cf0345b |
153 | $c->log->debug( "Loaded Chained actions:\n" . $paths->draw . "\n" ); |
007a7ca0 |
154 | $c->log->debug( "Unattached Chained actions:\n", $unattached_actions->draw . "\n" ) |
155 | if $has_unattached_actions; |
792b40ac |
156 | } |
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157 | |
ba3f8a81 |
158 | sub _list_extra_http_methods { |
159 | my ( $self, $action ) = @_; |
160 | return unless defined $action->list_extra_info->{HTTP_METHODS}; |
161 | return join(', ', @{$action->list_extra_info->{HTTP_METHODS}}); |
e72a3cd6 |
162 | |
ba3f8a81 |
163 | } |
164 | |
e72a3cd6 |
165 | sub _list_extra_consumes { |
166 | my ( $self, $action ) = @_; |
167 | return unless defined $action->list_extra_info->{CONSUMES}; |
168 | return join(', ', @{$action->list_extra_info->{CONSUMES}}); |
169 | } |
170 | |
342d2169 |
171 | sub _list_extra_scheme { |
172 | my ( $self, $action ) = @_; |
173 | return unless defined $action->list_extra_info->{Scheme}; |
174 | return uc $action->list_extra_info->{Scheme}; |
175 | } |
e72a3cd6 |
176 | |
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177 | =head2 $self->match( $c, $path ) |
178 | |
05a90578 |
179 | Calls C<recurse_match> to see if a chain matches the C<$path>. |
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180 | |
181 | =cut |
182 | |
183 | sub match { |
184 | my ( $self, $c, $path ) = @_; |
185 | |
e5ecd5bc |
186 | my $request = $c->request; |
187 | return 0 if @{$request->args}; |
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188 | |
189 | my @parts = split('/', $path); |
190 | |
6365b527 |
191 | my ($chain, $captures, $parts) = $self->recurse_match($c, '/', \@parts); |
634780e0 |
192 | |
193 | if ($parts && @$parts) { |
194 | for my $arg (@$parts) { |
195 | $arg =~ s/%([0-9A-Fa-f]{2})/chr(hex($1))/eg; |
196 | push @{$request->args}, $arg; |
197 | } |
198 | } |
141459fa |
199 | |
200 | return 0 unless $chain; |
201 | |
202 | my $action = Catalyst::ActionChain->from_chain($chain); |
203 | |
e5ecd5bc |
204 | $request->action("/${action}"); |
205 | $request->match("/${action}"); |
206 | $request->captures($captures); |
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207 | $c->action($action); |
208 | $c->namespace( $action->namespace ); |
209 | |
210 | return 1; |
211 | } |
212 | |
213 | =head2 $self->recurse_match( $c, $parent, \@path_parts ) |
214 | |
05a90578 |
215 | Recursive search for a matching chain. |
141459fa |
216 | |
217 | =cut |
218 | |
219 | sub recurse_match { |
220 | my ( $self, $c, $parent, $path_parts ) = @_; |
be5cb4e4 |
221 | my $children = $self->_children_of->{$parent}; |
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222 | return () unless $children; |
6b495723 |
223 | my $best_action; |
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224 | my @captures; |
1b04b972 |
225 | TRY: foreach my $try_part (sort { length($b) <=> length($a) } |
cdc97b63 |
226 | keys %$children) { |
1b04b972 |
227 | # $b then $a to try longest part first |
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228 | my @parts = @$path_parts; |
229 | if (length $try_part) { # test and strip PathPart |
230 | next TRY unless |
231 | ($try_part eq join('/', # assemble equal number of parts |
232 | splice( # and strip them off @parts as well |
792b40ac |
233 | @parts, 0, scalar(@{[split('/', $try_part)]}) |
234 | ))); # @{[]} to avoid split to @_ |
141459fa |
235 | } |
236 | my @try_actions = @{$children->{$try_part}}; |
237 | TRY_ACTION: foreach my $action (@try_actions) { |
1c34f703 |
238 | if (my $capture_attr = $action->attributes->{CaptureArgs}) { |
3f91cb25 |
239 | my $capture_count = $capture_attr->[0] || 0; |
f505df49 |
240 | |
241 | # Short-circuit if not enough remaining parts |
3f91cb25 |
242 | next TRY_ACTION unless @parts >= $capture_count; |
f505df49 |
243 | |
141459fa |
244 | my @captures; |
245 | my @parts = @parts; # localise |
7a7ac23c |
246 | |
1c34f703 |
247 | # strip CaptureArgs into list |
3f91cb25 |
248 | push(@captures, splice(@parts, 0, $capture_count)); |
7a7ac23c |
249 | |
1279064a |
250 | # check if the action may fit, depending on a given test by the app |
251 | if ($action->can('match_captures')) { next TRY_ACTION unless $action->match_captures($c, \@captures) } |
252 | |
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253 | # try the remaining parts against children of this action |
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254 | my ($actions, $captures, $action_parts, $n_pathparts) = $self->recurse_match( |
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255 | $c, '/'.$action->reverse, \@parts |
256 | ); |
2f381252 |
257 | # No best action currently |
258 | # OR The action has less parts |
259 | # OR The action has equal parts but less captured data (ergo more defined) |
260 | if ($actions && |
261 | (!$best_action || |
f4dbb497 |
262 | $#$action_parts < $#{$best_action->{parts}} || |
2f381252 |
263 | ($#$action_parts == $#{$best_action->{parts}} && |
0c78acb6 |
264 | $#$captures < $#{$best_action->{captures}} && |
265 | $n_pathparts > $best_action->{n_pathparts}))) { |
266 | my @pathparts = split /\//, $action->attributes->{PathPart}->[0]; |
6b495723 |
267 | $best_action = { |
268 | actions => [ $action, @$actions ], |
269 | captures=> [ @captures, @$captures ], |
0c78acb6 |
270 | parts => $action_parts, |
271 | n_pathparts => scalar(@pathparts) + $n_pathparts, |
272 | }; |
6b495723 |
273 | } |
274 | } |
275 | else { |
7a7ac23c |
276 | { |
277 | local $c->req->{arguments} = [ @{$c->req->args}, @parts ]; |
278 | next TRY_ACTION unless $action->match($c); |
279 | } |
5c6d829d |
280 | my $args_attr = $action->attributes->{Args}->[0]; |
0c78acb6 |
281 | my @pathparts = split /\//, $action->attributes->{PathPart}->[0]; |
953c176d |
282 | # No best action currently |
283 | # OR This one matches with fewer parts left than the current best action, |
284 | # And therefore is a better match |
b0ad47c1 |
285 | # OR No parts and this expects 0 |
953c176d |
286 | # The current best action might also be Args(0), |
287 | # but we couldn't chose between then anyway so we'll take the last seen |
288 | |
219b4f88 |
289 | if ( |
290 | !$best_action || |
953c176d |
291 | @parts < @{$best_action->{parts}} || |
219b4f88 |
292 | ( |
293 | !@parts && |
294 | defined($args_attr) && |
09914a47 |
295 | ( |
296 | $args_attr eq "0" && |
7a504990 |
297 | ( |
298 | ($c->config->{use_chained_args_0_special_case}||0) || |
299 | ( |
300 | exists($best_action->{args_attr}) && defined($best_action->{args_attr}) ? |
301 | ($best_action->{args_attr} ne 0) : 1 |
302 | ) |
303 | ) |
09914a47 |
304 | ) |
219b4f88 |
305 | ) |
306 | ){ |
6b495723 |
307 | $best_action = { |
308 | actions => [ $action ], |
309 | captures=> [], |
0c78acb6 |
310 | parts => \@parts, |
09914a47 |
311 | args_attr => $args_attr, |
0c78acb6 |
312 | n_pathparts => scalar(@pathparts), |
313 | }; |
953c176d |
314 | } |
141459fa |
315 | } |
316 | } |
317 | } |
0c78acb6 |
318 | return @$best_action{qw/actions captures parts n_pathparts/} if $best_action; |
141459fa |
319 | return (); |
320 | } |
321 | |
322 | =head2 $self->register( $c, $action ) |
323 | |
05a90578 |
324 | Calls register_path for every Path attribute for the given $action. |
141459fa |
325 | |
326 | =cut |
327 | |
2e29aec2 |
328 | sub _check_args_attr { |
329 | my ( $self, $action, $name ) = @_; |
330 | |
331 | return unless exists $action->attributes->{$name}; |
332 | |
333 | if (@{$action->attributes->{$name}} > 1) { |
334 | Catalyst::Exception->throw( |
335 | "Multiple $name attributes not supported registering " . $action->reverse() |
336 | ); |
337 | } |
338 | my $args = $action->attributes->{$name}->[0]; |
339 | if (defined($args) and not ( |
340 | Scalar::Util::looks_like_number($args) and |
2782bef2 |
341 | int($args) == $args and $args >= 0 |
2e29aec2 |
342 | )) { |
343 | require Data::Dumper; |
344 | local $Data::Dumper::Terse = 1; |
345 | local $Data::Dumper::Indent = 0; |
346 | $args = Data::Dumper::Dumper($args); |
347 | Catalyst::Exception->throw( |
348 | "Invalid $name($args) for action " . $action->reverse() . |
349 | " (use '$name' or '$name(<number>)')" |
350 | ); |
351 | } |
352 | } |
353 | |
141459fa |
354 | sub register { |
355 | my ( $self, $c, $action ) = @_; |
356 | |
1dc8af44 |
357 | my @chained_attr = @{ $action->attributes->{Chained} || [] }; |
141459fa |
358 | |
1dc8af44 |
359 | return 0 unless @chained_attr; |
141459fa |
360 | |
2f381252 |
361 | if (@chained_attr > 1) { |
141459fa |
362 | Catalyst::Exception->throw( |
5882c86e |
363 | "Multiple Chained attributes not supported registering ${action}" |
141459fa |
364 | ); |
365 | } |
13c6b4cc |
366 | my $chained_to = $chained_attr[0]; |
141459fa |
367 | |
13c6b4cc |
368 | Catalyst::Exception->throw( |
369 | "Actions cannot chain to themselves registering /${action}" |
370 | ) if ($chained_to eq '/' . $action); |
371 | |
372 | my $children = ($self->_children_of->{ $chained_to } ||= {}); |
141459fa |
373 | |
374 | my @path_part = @{ $action->attributes->{PathPart} || [] }; |
375 | |
09461385 |
376 | my $part = $action->name; |
141459fa |
377 | |
09461385 |
378 | if (@path_part == 1 && defined $path_part[0]) { |
379 | $part = $path_part[0]; |
141459fa |
380 | } elsif (@path_part > 1) { |
381 | Catalyst::Exception->throw( |
f3414019 |
382 | "Multiple PathPart attributes not supported registering " . $action->reverse() |
141459fa |
383 | ); |
384 | } |
385 | |
8a6a6581 |
386 | if ($part =~ m(^/)) { |
387 | Catalyst::Exception->throw( |
f3414019 |
388 | "Absolute parameters to PathPart not allowed registering " . $action->reverse() |
8a6a6581 |
389 | ); |
390 | } |
391 | |
0ca510f0 |
392 | my $encoded_part = URI->new($part)->canonical; |
393 | $encoded_part =~ s{(?<=[^/])/+\z}{}; |
792b40ac |
394 | |
0ca510f0 |
395 | $action->attributes->{PathPart} = [ $encoded_part ]; |
396 | |
397 | unshift(@{ $children->{$encoded_part} ||= [] }, $action); |
141459fa |
398 | |
be5cb4e4 |
399 | $self->_actions->{'/'.$action->reverse} = $action; |
792b40ac |
400 | |
2e29aec2 |
401 | foreach my $name (qw(Args CaptureArgs)) { |
402 | $self->_check_args_attr($action, $name); |
403 | } |
404 | |
405 | if (exists $action->attributes->{Args} and exists $action->attributes->{CaptureArgs}) { |
406 | Catalyst::Exception->throw( |
bc71493a |
407 | "Combining Args and CaptureArgs attributes not supported registering " . |
408 | $action->reverse() |
2e29aec2 |
409 | ); |
dd97c1ac |
410 | } |
411 | |
1c34f703 |
412 | unless ($action->attributes->{CaptureArgs}) { |
be5cb4e4 |
413 | unshift(@{ $self->_endpoints }, $action); |
792b40ac |
414 | } |
415 | |
416 | return 1; |
141459fa |
417 | } |
418 | |
419 | =head2 $self->uri_for_action($action, $captures) |
420 | |
05a90578 |
421 | Get the URI part for the action, using C<$captures> to fill |
422 | the capturing parts. |
141459fa |
423 | |
424 | =cut |
425 | |
426 | sub uri_for_action { |
427 | my ( $self, $action, $captures ) = @_; |
428 | |
5882c86e |
429 | return undef unless ($action->attributes->{Chained} |
8b13f357 |
430 | && !$action->attributes->{CaptureArgs}); |
792b40ac |
431 | |
432 | my @parts = (); |
433 | my @captures = @$captures; |
434 | my $parent = "DUMMY"; |
435 | my $curr = $action; |
436 | while ($curr) { |
1c34f703 |
437 | if (my $cap = $curr->attributes->{CaptureArgs}) { |
84ac8ab9 |
438 | return undef unless @captures >= ($cap->[0]||0); # not enough captures |
8b13f357 |
439 | if ($cap->[0]) { |
f9155483 |
440 | unshift(@parts, splice(@captures, -$cap->[0])); |
8b13f357 |
441 | } |
792b40ac |
442 | } |
77771155 |
443 | if (my $pp = $curr->attributes->{PathPart}) { |
792b40ac |
444 | unshift(@parts, $pp->[0]) |
8b13f357 |
445 | if (defined($pp->[0]) && length($pp->[0])); |
792b40ac |
446 | } |
5882c86e |
447 | $parent = $curr->attributes->{Chained}->[0]; |
be5cb4e4 |
448 | $curr = $self->_actions->{$parent}; |
141459fa |
449 | } |
792b40ac |
450 | |
451 | return undef unless $parent eq '/'; # fail for dangling action |
452 | |
453 | return undef if @captures; # fail for too many captures |
454 | |
455 | return join('/', '', @parts); |
59d5a638 |
456 | |
141459fa |
457 | } |
458 | |
ae0e35ee |
459 | =head2 $c->expand_action($action) |
460 | |
b0ad47c1 |
461 | Return a list of actions that represents a chained action. See |
ae0e35ee |
462 | L<Catalyst::Dispatcher> for more info. You probably want to |
463 | use the expand_action it provides rather than this directly. |
464 | |
465 | =cut |
466 | |
52f71256 |
467 | sub expand_action { |
468 | my ($self, $action) = @_; |
469 | |
470 | return unless $action->attributes && $action->attributes->{Chained}; |
471 | |
472 | my @chain; |
473 | my $curr = $action; |
474 | |
475 | while ($curr) { |
476 | push @chain, $curr; |
477 | my $parent = $curr->attributes->{Chained}->[0]; |
478 | $curr = $self->_actions->{$parent}; |
479 | } |
480 | |
481 | return Catalyst::ActionChain->from_chain([reverse @chain]); |
482 | } |
483 | |
e5ecd5bc |
484 | __PACKAGE__->meta->make_immutable; |
f4de8c99 |
485 | 1; |
e5ecd5bc |
486 | |
05a90578 |
487 | =head1 USAGE |
488 | |
489 | =head2 Introduction |
490 | |
491 | The C<Chained> attribute allows you to chain public path parts together |
67869327 |
492 | by their private names. A chain part's path can be specified with |
493 | C<PathPart> and can be declared to expect an arbitrary number of |
494 | arguments. The endpoint of the chain specifies how many arguments it |
495 | gets through the C<Args> attribute. C<:Args(0)> would be none at all, |
496 | C<:Args> without an integer would be unlimited. The path parts that |
497 | aren't endpoints are using C<CaptureArgs> to specify how many parameters |
498 | they expect to receive. As an example setup: |
05a90578 |
499 | |
500 | package MyApp::Controller::Greeting; |
501 | use base qw/ Catalyst::Controller /; |
502 | |
503 | # this is the beginning of our chain |
504 | sub hello : PathPart('hello') Chained('/') CaptureArgs(1) { |
505 | my ( $self, $c, $integer ) = @_; |
506 | $c->stash->{ message } = "Hello "; |
507 | $c->stash->{ arg_sum } = $integer; |
508 | } |
509 | |
510 | # this is our endpoint, because it has no :CaptureArgs |
511 | sub world : PathPart('world') Chained('hello') Args(1) { |
512 | my ( $self, $c, $integer ) = @_; |
513 | $c->stash->{ message } .= "World!"; |
514 | $c->stash->{ arg_sum } += $integer; |
515 | |
516 | $c->response->body( join "<br/>\n" => |
517 | $c->stash->{ message }, $c->stash->{ arg_sum } ); |
518 | } |
519 | |
520 | The debug output provides a separate table for chained actions, showing |
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521 | the whole chain as it would match and the actions it contains. Here's an |
522 | example of the startup output with our actions above: |
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523 | |
524 | ... |
525 | [debug] Loaded Path Part actions: |
526 | .-----------------------+------------------------------. |
527 | | Path Spec | Private | |
528 | +-----------------------+------------------------------+ |
529 | | /hello/*/world/* | /greeting/hello (1) | |
530 | | | => /greeting/world | |
531 | '-----------------------+------------------------------' |
532 | ... |
533 | |
67869327 |
534 | As you can see, Catalyst only deals with chains as whole paths and |
535 | builds one for each endpoint, which are the actions with C<:Chained> but |
536 | without C<:CaptureArgs>. |
05a90578 |
537 | |
538 | Let's assume this application gets a request at the path |
67869327 |
539 | C</hello/23/world/12>. What happens then? First, Catalyst will dispatch |
540 | to the C<hello> action and pass the value C<23> as an argument to it |
541 | after the context. It does so because we have previously used |
542 | C<:CaptureArgs(1)> to declare that it has one path part after itself as |
543 | its argument. We told Catalyst that this is the beginning of the chain |
544 | by specifying C<:Chained('/')>. Also note that instead of saying |
545 | C<:PathPart('hello')> we could also just have said C<:PathPart>, as it |
546 | defaults to the name of the action. |
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547 | |
548 | After C<hello> has run, Catalyst goes on to dispatch to the C<world> |
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549 | action. This is the last action to be called: Catalyst knows this is an |
550 | endpoint because we did not specify a C<:CaptureArgs> |
551 | attribute. Nevertheless we specify that this action expects an argument, |
552 | but at this point we're using C<:Args(1)> to do that. We could also have |
553 | said C<:Args> or left it out altogether, which would mean this action |
554 | would get all arguments that are there. This action's C<:Chained> |
555 | attribute says C<hello> and tells Catalyst that the C<hello> action in |
556 | the current controller is its parent. |
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557 | |
558 | With this we have built a chain consisting of two public path parts. |
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559 | C<hello> captures one part of the path as its argument, and also |
560 | specifies the path root as its parent. So this part is |
561 | C</hello/$arg>. The next part is the endpoint C<world>, expecting one |
562 | argument. It sums up to the path part C<world/$arg>. This leads to a |
563 | complete chain of C</hello/$arg/world/$arg> which is matched against the |
564 | requested paths. |
565 | |
566 | This example application would, if run and called by e.g. |
567 | C</hello/23/world/12>, set the stash value C<message> to "Hello" and the |
568 | value C<arg_sum> to "23". The C<world> action would then append "World!" |
569 | to C<message> and add C<12> to the stash's C<arg_sum> value. For the |
570 | sake of simplicity no view is shown. Instead we just put the values of |
571 | the stash into our body. So the output would look like: |
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572 | |
573 | Hello World! |
574 | 35 |
575 | |
67869327 |
576 | And our test server would have given us this debugging output for the |
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577 | request: |
578 | |
579 | ... |
580 | [debug] "GET" request for "hello/23/world/12" from "127.0.0.1" |
581 | [debug] Path is "/greeting/world" |
582 | [debug] Arguments are "12" |
583 | [info] Request took 0.164113s (6.093/s) |
584 | .------------------------------------------+-----------. |
585 | | Action | Time | |
586 | +------------------------------------------+-----------+ |
587 | | /greeting/hello | 0.000029s | |
588 | | /greeting/world | 0.000024s | |
589 | '------------------------------------------+-----------' |
590 | ... |
591 | |
67869327 |
592 | What would be common uses of this dispatch technique? It gives the |
593 | possibility to split up logic that contains steps that each depend on |
594 | each other. An example would be, for example, a wiki path like |
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595 | C</wiki/FooBarPage/rev/23/view>. This chain can be easily built with |
596 | these actions: |
597 | |
598 | sub wiki : PathPart('wiki') Chained('/') CaptureArgs(1) { |
599 | my ( $self, $c, $page_name ) = @_; |
600 | # load the page named $page_name and put the object |
601 | # into the stash |
602 | } |
603 | |
604 | sub rev : PathPart('rev') Chained('wiki') CaptureArgs(1) { |
605 | my ( $self, $c, $revision_id ) = @_; |
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606 | # use the page object in the stash to get at its |
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607 | # revision with number $revision_id |
608 | } |
609 | |
610 | sub view : PathPart Chained('rev') Args(0) { |
611 | my ( $self, $c ) = @_; |
67869327 |
612 | # display the revision in our stash. Another option |
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613 | # would be to forward a compatible object to the action |
614 | # that displays the default wiki pages, unless we want |
615 | # a different interface here, for example restore |
616 | # functionality. |
617 | } |
618 | |
67869327 |
619 | It would now be possible to add other endpoints, for example C<restore> |
620 | to restore this specific revision as the current state. |
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621 | |
67869327 |
622 | You don't have to put all the chained actions in one controller. The |
623 | specification of the parent through C<:Chained> also takes an absolute |
624 | action path as its argument. Just specify it with a leading C</>. |
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625 | |
626 | If you want, for example, to have actions for the public paths |
67869327 |
627 | C</foo/12/edit> and C</foo/12>, just specify two actions with |
05a90578 |
628 | C<:PathPart('foo')> and C<:Chained('/')>. The handler for the former |
67869327 |
629 | path needs a C<:CaptureArgs(1)> attribute and a endpoint with |
05a90578 |
630 | C<:PathPart('edit')> and C<:Chained('foo')>. For the latter path give |
631 | the action just a C<:Args(1)> to mark it as endpoint. This sums up to |
632 | this debugging output: |
633 | |
634 | ... |
635 | [debug] Loaded Path Part actions: |
636 | .-----------------------+------------------------------. |
637 | | Path Spec | Private | |
638 | +-----------------------+------------------------------+ |
639 | | /foo/* | /controller/foo_view | |
640 | | /foo/*/edit | /controller/foo_load (1) | |
641 | | | => /controller/edit | |
642 | '-----------------------+------------------------------' |
643 | ... |
644 | |
b0ad47c1 |
645 | Here's a more detailed specification of the attributes belonging to |
05a90578 |
646 | C<:Chained>: |
647 | |
648 | =head2 Attributes |
649 | |
650 | =over 8 |
651 | |
652 | =item PathPart |
653 | |
654 | Sets the name of this part of the chain. If it is specified without |
655 | arguments, it takes the name of the action as default. So basically |
656 | C<sub foo :PathPart> and C<sub foo :PathPart('foo')> are identical. |
657 | This can also contain slashes to bind to a deeper level. An action |
658 | with C<sub bar :PathPart('foo/bar') :Chained('/')> would bind to |
659 | C</foo/bar/...>. If you don't specify C<:PathPart> it has the same |
660 | effect as using C<:PathPart>, it would default to the action name. |
661 | |
d21a2b27 |
662 | =item PathPrefix |
663 | |
664 | Sets PathPart to the path_prefix of the current controller. |
665 | |
05a90578 |
666 | =item Chained |
667 | |
668 | Has to be specified for every child in the chain. Possible values are |
d21a2b27 |
669 | absolute and relative private action paths or a single slash C</> to |
670 | tell Catalyst that this is the root of a chain. The attribute |
671 | C<:Chained> without arguments also defaults to the C</> behavior. |
672 | Relative action paths may use C<../> to refer to actions in parent |
673 | controllers. |
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674 | |
67869327 |
675 | Because you can specify an absolute path to the parent action, it |
676 | doesn't matter to Catalyst where that parent is located. So, if your |
677 | design requests it, you can redispatch a chain through any controller or |
678 | namespace you want. |
05a90578 |
679 | |
680 | Another interesting possibility gives C<:Chained('.')>, which chains |
67869327 |
681 | itself to an action with the path of the current controller's namespace. |
05a90578 |
682 | For example: |
683 | |
684 | # in MyApp::Controller::Foo |
685 | sub bar : Chained CaptureArgs(1) { ... } |
686 | |
687 | # in MyApp::Controller::Foo::Bar |
688 | sub baz : Chained('.') Args(1) { ... } |
689 | |
690 | This builds up a chain like C</bar/*/baz/*>. The specification of C<.> |
67869327 |
691 | as the argument to Chained here chains the C<baz> action to an action |
692 | with the path of the current controller namespace, namely |
693 | C</foo/bar>. That action chains directly to C</>, so the C</bar/*/baz/*> |
694 | chain comes out as the end product. |
05a90578 |
695 | |
d21a2b27 |
696 | =item ChainedParent |
697 | |
698 | Chains an action to another action with the same name in the parent |
699 | controller. For Example: |
700 | |
701 | # in MyApp::Controller::Foo |
702 | sub bar : Chained CaptureArgs(1) { ... } |
703 | |
704 | # in MyApp::Controller::Foo::Moo |
705 | sub bar : ChainedParent Args(1) { ... } |
706 | |
707 | This builds a chain like C</bar/*/bar/*>. |
708 | |
05a90578 |
709 | =item CaptureArgs |
710 | |
67869327 |
711 | Must be specified for every part of the chain that is not an |
05a90578 |
712 | endpoint. With this attribute Catalyst knows how many of the following |
67869327 |
713 | parts of the path (separated by C</>) this action wants to capture as |
714 | its arguments. If it doesn't expect any, just specify |
715 | C<:CaptureArgs(0)>. The captures get passed to the action's C<@_> right |
716 | after the context, but you can also find them as array references in |
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717 | C<$c-E<gt>request-E<gt>captures-E<gt>[$level]>. The C<$level> is the |
718 | level of the action in the chain that captured the parts of the path. |
719 | |
67869327 |
720 | An action that is part of a chain (that is, one that has a C<:Chained> |
721 | attribute) but has no C<:CaptureArgs> attribute is treated by Catalyst |
722 | as a chain end. |
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723 | |
724 | =item Args |
725 | |
726 | By default, endpoints receive the rest of the arguments in the path. You |
727 | can tell Catalyst through C<:Args> explicitly how many arguments your |
728 | endpoint expects, just like you can with C<:CaptureArgs>. Note that this |
67869327 |
729 | also affects whether this chain is invoked on a request. A chain with an |
05a90578 |
730 | endpoint specifying one argument will only match if exactly one argument |
731 | exists in the path. |
732 | |
733 | You can specify an exact number of arguments like C<:Args(3)>, including |
734 | C<0>. If you just say C<:Args> without any arguments, it is the same as |
67869327 |
735 | leaving it out altogether: The chain is matched regardless of the number |
05a90578 |
736 | of path parts after the endpoint. |
737 | |
67869327 |
738 | Just as with C<:CaptureArgs>, the arguments get passed to the action in |
05a90578 |
739 | C<@_> after the context object. They can also be reached through |
740 | C<$c-E<gt>request-E<gt>arguments>. |
741 | |
742 | =back |
743 | |
67869327 |
744 | =head2 Auto actions, dispatching and forwarding |
05a90578 |
745 | |
746 | Note that the list of C<auto> actions called depends on the private path |
67869327 |
747 | of the endpoint of the chain, not on the chained actions way. The |
748 | C<auto> actions will be run before the chain dispatching begins. In |
749 | every other aspect, C<auto> actions behave as documented. |
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750 | |
64111aca |
751 | The C<forward>ing to other actions does just what you would expect. i.e. |
e1207438 |
752 | only the target action is run. The actions that that action is chained |
753 | to are not run. |
754 | If you C<detach> out of a chain, the rest of the chain will not get |
755 | called after the C<detach>. |
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756 | |
22faeff5 |
757 | =head2 match_captures |
758 | |
759 | A method which can optionally be implemented by actions to |
760 | stop chain matching. |
761 | |
762 | See L<Catalyst::Action> for further details. |
763 | |
2f381252 |
764 | =head1 AUTHORS |
141459fa |
765 | |
2f381252 |
766 | Catalyst Contributors, see Catalyst.pm |
141459fa |
767 | |
768 | =head1 COPYRIGHT |
769 | |
536bee89 |
770 | This library is free software. You can redistribute it and/or modify it under |
141459fa |
771 | the same terms as Perl itself. |
772 | |
773 | =cut |
774 | |
775 | 1; |