/usr/share/perl5/Catalyst/DispatchType/Chained.pm is in libcatalyst-perl 5.90103-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 | package Catalyst::DispatchType::Chained;
use Moose;
extends 'Catalyst::DispatchType';
use Text::SimpleTable;
use Catalyst::ActionChain;
use Catalyst::Utils;
use URI;
use Scalar::Util ();
use Encode 2.21 'decode_utf8';
has _endpoints => (
is => 'rw',
isa => 'ArrayRef',
required => 1,
default => sub{ [] },
);
has _actions => (
is => 'rw',
isa => 'HashRef',
required => 1,
default => sub{ {} },
);
has _children_of => (
is => 'rw',
isa => 'HashRef',
required => 1,
default => sub{ {} },
);
no Moose;
# please don't perltidy this. hairy code within.
=head1 NAME
Catalyst::DispatchType::Chained - Path Part DispatchType
=head1 SYNOPSIS
Path part matching, allowing several actions to sequentially take care of processing a request:
# root action - captures one argument after it
sub foo_setup : Chained('/') PathPart('foo') CaptureArgs(1) {
my ( $self, $c, $foo_arg ) = @_;
...
}
# child action endpoint - takes one argument
sub bar : Chained('foo_setup') Args(1) {
my ( $self, $c, $bar_arg ) = @_;
...
}
=head1 DESCRIPTION
Dispatch type managing default behaviour. For more information on
dispatch types, see:
=over 4
=item * L<Catalyst::Manual::Intro> for how they affect application authors
=item * L<Catalyst::DispatchType> for implementation information.
=back
=head1 METHODS
=head2 $self->list($c)
Debug output for Path Part dispatch points
=cut
sub list {
my ( $self, $c ) = @_;
return unless $self->_endpoints;
my $avail_width = Catalyst::Utils::term_width() - 9;
my $col1_width = ($avail_width * .50) < 35 ? 35 : int($avail_width * .50);
my $col2_width = $avail_width - $col1_width;
my $paths = Text::SimpleTable->new(
[ $col1_width, 'Path Spec' ], [ $col2_width, 'Private' ],
);
my $has_unattached_actions;
my $unattached_actions = Text::SimpleTable->new(
[ $col1_width, 'Private' ], [ $col2_width, 'Missing parent' ],
);
ENDPOINT: foreach my $endpoint (
sort { $a->reverse cmp $b->reverse }
@{ $self->_endpoints }
) {
my $args = $endpoint->list_extra_info->{Args};
my @parts = (defined($endpoint->attributes->{Args}[0]) ? (("*") x $args) : '...');
my @parents = ();
my $parent = "DUMMY";
my $extra = $self->_list_extra_http_methods($endpoint);
my $consumes = $self->_list_extra_consumes($endpoint);
my $scheme = $self->_list_extra_scheme($endpoint);
my $curr = $endpoint;
while ($curr) {
if (my $cap = $curr->list_extra_info->{CaptureArgs}) {
unshift(@parts, (("*") x $cap));
}
if (my $pp = $curr->attributes->{PathPart}) {
unshift(@parts, $pp->[0])
if (defined $pp->[0] && length $pp->[0]);
}
$parent = $curr->attributes->{Chained}->[0];
$curr = $self->_actions->{$parent};
unshift(@parents, $curr) if $curr;
}
if ($parent ne '/') {
$has_unattached_actions = 1;
$unattached_actions->row('/' . ($parents[0] || $endpoint)->reverse, $parent);
next ENDPOINT;
}
my @rows;
foreach my $p (@parents) {
my $name = "/${p}";
if (defined(my $extra = $self->_list_extra_http_methods($p))) {
$name = "${extra} ${name}";
}
if (defined(my $cap = $p->list_extra_info->{CaptureArgs})) {
if($p->has_captures_constraints) {
my $tc = join ',', @{$p->captures_constraints};
$name .= " ($tc)";
} else {
$name .= " ($cap)";
}
}
if (defined(my $ct = $p->list_extra_info->{Consumes})) {
$name .= ' :'.$ct;
}
if (defined(my $s = $p->list_extra_info->{Scheme})) {
$scheme = uc $s;
}
unless ($p eq $parents[0]) {
$name = "-> ${name}";
}
push(@rows, [ '', $name ]);
}
if($endpoint->has_args_constraints) {
my $tc = join ',', @{$endpoint->args_constraints};
$endpoint .= " ($tc)";
} else {
$endpoint .= defined($endpoint->attributes->{Args}[0]) ? " ($args)" : " (...)";
}
push(@rows, [ '', (@rows ? "=> " : '').($extra ? "$extra " : ''). ($scheme ? "$scheme: ":'')."/${endpoint}". ($consumes ? " :$consumes":"" ) ]);
my @display_parts = map { $_ =~s/%([0-9A-Fa-f]{2})/chr(hex($1))/eg; decode_utf8 $_ } @parts;
$rows[0][0] = join('/', '', @display_parts) || '/';
$paths->row(@$_) for @rows;
}
$c->log->debug( "Loaded Chained actions:\n" . $paths->draw . "\n" );
$c->log->debug( "Unattached Chained actions:\n", $unattached_actions->draw . "\n" )
if $has_unattached_actions;
}
sub _list_extra_http_methods {
my ( $self, $action ) = @_;
return unless defined $action->list_extra_info->{HTTP_METHODS};
return join(', ', @{$action->list_extra_info->{HTTP_METHODS}});
}
sub _list_extra_consumes {
my ( $self, $action ) = @_;
return unless defined $action->list_extra_info->{CONSUMES};
return join(', ', @{$action->list_extra_info->{CONSUMES}});
}
sub _list_extra_scheme {
my ( $self, $action ) = @_;
return unless defined $action->list_extra_info->{Scheme};
return uc $action->list_extra_info->{Scheme};
}
=head2 $self->match( $c, $path )
Calls C<recurse_match> to see if a chain matches the C<$path>.
=cut
sub match {
my ( $self, $c, $path ) = @_;
my $request = $c->request;
return 0 if @{$request->args};
my @parts = split('/', $path);
my ($chain, $captures, $parts) = $self->recurse_match($c, '/', \@parts);
if ($parts && @$parts) {
for my $arg (@$parts) {
$arg =~ s/%([0-9A-Fa-f]{2})/chr(hex($1))/eg;
push @{$request->args}, $arg;
}
}
return 0 unless $chain;
my $action = Catalyst::ActionChain->from_chain($chain);
$request->action("/${action}");
$request->match("/${action}");
$request->captures($captures);
$c->action($action);
$c->namespace( $action->namespace );
return 1;
}
=head2 $self->recurse_match( $c, $parent, \@path_parts )
Recursive search for a matching chain.
=cut
sub recurse_match {
my ( $self, $c, $parent, $path_parts ) = @_;
my $children = $self->_children_of->{$parent};
return () unless $children;
my $best_action;
my @captures;
TRY: foreach my $try_part (sort { length($b) <=> length($a) }
keys %$children) {
# $b then $a to try longest part first
my @parts = @$path_parts;
if (length $try_part) { # test and strip PathPart
next TRY unless
($try_part eq join('/', # assemble equal number of parts
splice( # and strip them off @parts as well
@parts, 0, scalar(@{[split('/', $try_part)]})
))); # @{[]} to avoid split to @_
}
my @try_actions = @{$children->{$try_part}};
TRY_ACTION: foreach my $action (@try_actions) {
if (my $capture_attr = $action->attributes->{CaptureArgs}) {
my $capture_count = $action->number_of_captures|| 0;
# Short-circuit if not enough remaining parts
next TRY_ACTION unless @parts >= $capture_count;
my @captures;
my @parts = @parts; # localise
# strip CaptureArgs into list
push(@captures, splice(@parts, 0, $capture_count));
# check if the action may fit, depending on a given test by the app
next TRY_ACTION unless $action->match_captures($c, \@captures);
# try the remaining parts against children of this action
my ($actions, $captures, $action_parts, $n_pathparts) = $self->recurse_match(
$c, '/'.$action->reverse, \@parts
);
# No best action currently
# OR The action has less parts
# OR The action has equal parts but less captured data (ergo more defined)
if ($actions &&
(!$best_action ||
$#$action_parts < $#{$best_action->{parts}} ||
($#$action_parts == $#{$best_action->{parts}} &&
$#$captures < $#{$best_action->{captures}} &&
$n_pathparts > $best_action->{n_pathparts}))) {
my @pathparts = split /\//, $action->attributes->{PathPart}->[0];
$best_action = {
actions => [ $action, @$actions ],
captures=> [ @captures, @$captures ],
parts => $action_parts,
n_pathparts => scalar(@pathparts) + $n_pathparts,
};
}
}
else {
{
local $c->req->{arguments} = [ @{$c->req->args}, @parts ];
next TRY_ACTION unless $action->match($c);
}
my $args_attr = $action->attributes->{Args}->[0];
my $args_count = $action->normalized_arg_number;
my @pathparts = split /\//, $action->attributes->{PathPart}->[0];
# No best action currently
# OR This one matches with fewer parts left than the current best action,
# And therefore is a better match
# OR No parts and this expects 0
# The current best action might also be Args(0),
# but we couldn't chose between then anyway so we'll take the last seen
if (
!$best_action ||
@parts < @{$best_action->{parts}} ||
(
!@parts &&
defined($args_attr) &&
(
$args_count eq "0" &&
(
($c->config->{use_chained_args_0_special_case}||0) ||
(
exists($best_action->{args_count}) && defined($best_action->{args_count}) ?
($best_action->{args_count} ne 0) : 1
)
)
)
)
){
$best_action = {
actions => [ $action ],
captures=> [],
parts => \@parts,
args_count => $args_count,
n_pathparts => scalar(@pathparts),
};
}
}
}
}
return @$best_action{qw/actions captures parts n_pathparts/} if $best_action;
return ();
}
=head2 $self->register( $c, $action )
Calls register_path for every Path attribute for the given $action.
=cut
sub register {
my ( $self, $c, $action ) = @_;
my @chained_attr = @{ $action->attributes->{Chained} || [] };
return 0 unless @chained_attr;
if (@chained_attr > 1) {
Catalyst::Exception->throw(
"Multiple Chained attributes not supported registering ${action}"
);
}
my $chained_to = $chained_attr[0];
Catalyst::Exception->throw(
"Actions cannot chain to themselves registering /${action}"
) if ($chained_to eq '/' . $action);
my $children = ($self->_children_of->{ $chained_to } ||= {});
my @path_part = @{ $action->attributes->{PathPart} || [] };
my $part = $action->name;
if (@path_part == 1 && defined $path_part[0]) {
$part = $path_part[0];
} elsif (@path_part > 1) {
Catalyst::Exception->throw(
"Multiple PathPart attributes not supported registering " . $action->reverse()
);
}
if ($part =~ m(^/)) {
Catalyst::Exception->throw(
"Absolute parameters to PathPart not allowed registering " . $action->reverse()
);
}
my $encoded_part = URI->new($part)->canonical;
$encoded_part =~ s{(?<=[^/])/+\z}{};
$action->attributes->{PathPart} = [ $encoded_part ];
unshift(@{ $children->{$encoded_part} ||= [] }, $action);
$self->_actions->{'/'.$action->reverse} = $action;
if (exists $action->attributes->{Args} and exists $action->attributes->{CaptureArgs}) {
Catalyst::Exception->throw(
"Combining Args and CaptureArgs attributes not supported registering " .
$action->reverse()
);
}
unless ($action->attributes->{CaptureArgs}) {
unshift(@{ $self->_endpoints }, $action);
}
return 1;
}
=head2 $self->uri_for_action($action, $captures)
Get the URI part for the action, using C<$captures> to fill
the capturing parts.
=cut
sub uri_for_action {
my ( $self, $action, $captures ) = @_;
return undef unless ($action->attributes->{Chained}
&& !$action->attributes->{CaptureArgs});
my @parts = ();
my @captures = @$captures;
my $parent = "DUMMY";
my $curr = $action;
# If this is an action chain get the last action in the chain
if($curr->can('chain') ) {
$curr = ${$curr->chain}[-1];
}
while ($curr) {
if (my $cap = $curr->number_of_captures) {
return undef unless @captures >= $cap; # not enough captures
if ($cap) {
unshift(@parts, splice(@captures, -$cap));
}
}
if (my $pp = $curr->attributes->{PathPart}) {
unshift(@parts, $pp->[0])
if (defined($pp->[0]) && length($pp->[0]));
}
$parent = $curr->attributes->{Chained}->[0];
$curr = $self->_actions->{$parent};
}
return undef unless $parent eq '/'; # fail for dangling action
return undef if @captures; # fail for too many captures
return join('/', '', @parts);
}
=head2 $c->expand_action($action)
Return a list of actions that represents a chained action. See
L<Catalyst::Dispatcher> for more info. You probably want to
use the expand_action it provides rather than this directly.
=cut
sub expand_action {
my ($self, $action) = @_;
return unless $action->attributes && $action->attributes->{Chained};
my @chain;
my $curr = $action;
while ($curr) {
push @chain, $curr;
my $parent = $curr->attributes->{Chained}->[0];
$curr = $self->_actions->{$parent};
}
return Catalyst::ActionChain->from_chain([reverse @chain]);
}
__PACKAGE__->meta->make_immutable;
1;
=head1 USAGE
=head2 Introduction
The C<Chained> attribute allows you to chain public path parts together
by their private names. A chain part's path can be specified with
C<PathPart> and can be declared to expect an arbitrary number of
arguments. The endpoint of the chain specifies how many arguments it
gets through the C<Args> attribute. C<:Args(0)> would be none at all,
C<:Args> without an integer would be unlimited. The path parts that
aren't endpoints are using C<CaptureArgs> to specify how many parameters
they expect to receive. As an example setup:
package MyApp::Controller::Greeting;
use base qw/ Catalyst::Controller /;
# this is the beginning of our chain
sub hello : PathPart('hello') Chained('/') CaptureArgs(1) {
my ( $self, $c, $integer ) = @_;
$c->stash->{ message } = "Hello ";
$c->stash->{ arg_sum } = $integer;
}
# this is our endpoint, because it has no :CaptureArgs
sub world : PathPart('world') Chained('hello') Args(1) {
my ( $self, $c, $integer ) = @_;
$c->stash->{ message } .= "World!";
$c->stash->{ arg_sum } += $integer;
$c->response->body( join "<br/>\n" =>
$c->stash->{ message }, $c->stash->{ arg_sum } );
}
The debug output provides a separate table for chained actions, showing
the whole chain as it would match and the actions it contains. Here's an
example of the startup output with our actions above:
...
[debug] Loaded Path Part actions:
.-----------------------+------------------------------.
| Path Spec | Private |
+-----------------------+------------------------------+
| /hello/*/world/* | /greeting/hello (1) |
| | => /greeting/world |
'-----------------------+------------------------------'
...
As you can see, Catalyst only deals with chains as whole paths and
builds one for each endpoint, which are the actions with C<:Chained> but
without C<:CaptureArgs>.
Let's assume this application gets a request at the path
C</hello/23/world/12>. What happens then? First, Catalyst will dispatch
to the C<hello> action and pass the value C<23> as an argument to it
after the context. It does so because we have previously used
C<:CaptureArgs(1)> to declare that it has one path part after itself as
its argument. We told Catalyst that this is the beginning of the chain
by specifying C<:Chained('/')>. Also note that instead of saying
C<:PathPart('hello')> we could also just have said C<:PathPart>, as it
defaults to the name of the action.
After C<hello> has run, Catalyst goes on to dispatch to the C<world>
action. This is the last action to be called: Catalyst knows this is an
endpoint because we did not specify a C<:CaptureArgs>
attribute. Nevertheless we specify that this action expects an argument,
but at this point we're using C<:Args(1)> to do that. We could also have
said C<:Args> or left it out altogether, which would mean this action
would get all arguments that are there. This action's C<:Chained>
attribute says C<hello> and tells Catalyst that the C<hello> action in
the current controller is its parent.
With this we have built a chain consisting of two public path parts.
C<hello> captures one part of the path as its argument, and also
specifies the path root as its parent. So this part is
C</hello/$arg>. The next part is the endpoint C<world>, expecting one
argument. It sums up to the path part C<world/$arg>. This leads to a
complete chain of C</hello/$arg/world/$arg> which is matched against the
requested paths.
This example application would, if run and called by e.g.
C</hello/23/world/12>, set the stash value C<message> to "Hello" and the
value C<arg_sum> to "23". The C<world> action would then append "World!"
to C<message> and add C<12> to the stash's C<arg_sum> value. For the
sake of simplicity no view is shown. Instead we just put the values of
the stash into our body. So the output would look like:
Hello World!
35
And our test server would have given us this debugging output for the
request:
...
[debug] "GET" request for "hello/23/world/12" from "127.0.0.1"
[debug] Path is "/greeting/world"
[debug] Arguments are "12"
[info] Request took 0.164113s (6.093/s)
.------------------------------------------+-----------.
| Action | Time |
+------------------------------------------+-----------+
| /greeting/hello | 0.000029s |
| /greeting/world | 0.000024s |
'------------------------------------------+-----------'
...
What would be common uses of this dispatch technique? It gives the
possibility to split up logic that contains steps that each depend on
each other. An example would be, for example, a wiki path like
C</wiki/FooBarPage/rev/23/view>. This chain can be easily built with
these actions:
sub wiki : PathPart('wiki') Chained('/') CaptureArgs(1) {
my ( $self, $c, $page_name ) = @_;
# load the page named $page_name and put the object
# into the stash
}
sub rev : PathPart('rev') Chained('wiki') CaptureArgs(1) {
my ( $self, $c, $revision_id ) = @_;
# use the page object in the stash to get at its
# revision with number $revision_id
}
sub view : PathPart Chained('rev') Args(0) {
my ( $self, $c ) = @_;
# display the revision in our stash. Another option
# would be to forward a compatible object to the action
# that displays the default wiki pages, unless we want
# a different interface here, for example restore
# functionality.
}
It would now be possible to add other endpoints, for example C<restore>
to restore this specific revision as the current state.
You don't have to put all the chained actions in one controller. The
specification of the parent through C<:Chained> also takes an absolute
action path as its argument. Just specify it with a leading C</>.
If you want, for example, to have actions for the public paths
C</foo/12/edit> and C</foo/12>, just specify two actions with
C<:PathPart('foo')> and C<:Chained('/')>. The handler for the former
path needs a C<:CaptureArgs(1)> attribute and a endpoint with
C<:PathPart('edit')> and C<:Chained('foo')>. For the latter path give
the action just a C<:Args(1)> to mark it as endpoint. This sums up to
this debugging output:
...
[debug] Loaded Path Part actions:
.-----------------------+------------------------------.
| Path Spec | Private |
+-----------------------+------------------------------+
| /foo/* | /controller/foo_view |
| /foo/*/edit | /controller/foo_load (1) |
| | => /controller/edit |
'-----------------------+------------------------------'
...
Here's a more detailed specification of the attributes belonging to
C<:Chained>:
=head2 Attributes
=over 8
=item PathPart
Sets the name of this part of the chain. If it is specified without
arguments, it takes the name of the action as default. So basically
C<sub foo :PathPart> and C<sub foo :PathPart('foo')> are identical.
This can also contain slashes to bind to a deeper level. An action
with C<sub bar :PathPart('foo/bar') :Chained('/')> would bind to
C</foo/bar/...>. If you don't specify C<:PathPart> it has the same
effect as using C<:PathPart>, it would default to the action name.
=item PathPrefix
Sets PathPart to the path_prefix of the current controller.
=item Chained
Has to be specified for every child in the chain. Possible values are
absolute and relative private action paths or a single slash C</> to
tell Catalyst that this is the root of a chain. The attribute
C<:Chained> without arguments also defaults to the C</> behavior.
Relative action paths may use C<../> to refer to actions in parent
controllers.
Because you can specify an absolute path to the parent action, it
doesn't matter to Catalyst where that parent is located. So, if your
design requests it, you can redispatch a chain through any controller or
namespace you want.
Another interesting possibility gives C<:Chained('.')>, which chains
itself to an action with the path of the current controller's namespace.
For example:
# in MyApp::Controller::Foo
sub bar : Chained CaptureArgs(1) { ... }
# in MyApp::Controller::Foo::Bar
sub baz : Chained('.') Args(1) { ... }
This builds up a chain like C</bar/*/baz/*>. The specification of C<.>
as the argument to Chained here chains the C<baz> action to an action
with the path of the current controller namespace, namely
C</foo/bar>. That action chains directly to C</>, so the C</bar/*/baz/*>
chain comes out as the end product.
=item ChainedParent
Chains an action to another action with the same name in the parent
controller. For Example:
# in MyApp::Controller::Foo
sub bar : Chained CaptureArgs(1) { ... }
# in MyApp::Controller::Foo::Moo
sub bar : ChainedParent Args(1) { ... }
This builds a chain like C</bar/*/bar/*>.
=item CaptureArgs
Must be specified for every part of the chain that is not an
endpoint. With this attribute Catalyst knows how many of the following
parts of the path (separated by C</>) this action wants to capture as
its arguments. If it doesn't expect any, just specify
C<:CaptureArgs(0)>. The captures get passed to the action's C<@_> right
after the context, but you can also find them as array references in
C<$c-E<gt>request-E<gt>captures-E<gt>[$level]>. The C<$level> is the
level of the action in the chain that captured the parts of the path.
An action that is part of a chain (that is, one that has a C<:Chained>
attribute) but has no C<:CaptureArgs> attribute is treated by Catalyst
as a chain end.
Allowed values for CaptureArgs is a single integer (CaptureArgs(2), meaning two
allowed) or you can declare a L<Moose>, L<MooseX::Types> or L<Type::Tiny>
named constraint such as CaptureArgs(Int,Str) would require two args with
the first being a Integer and the second a string. You may declare your own
custom type constraints and import them into the controller namespace:
package MyApp::Controller::Root;
use Moose;
use MooseX::MethodAttributes;
use MyApp::Types qw/Int/;
extends 'Catalyst::Controller';
sub chain_base :Chained(/) CaptureArgs(1) { }
sub any_priority_chain :Chained(chain_base) PathPart('') Args(1) { }
sub int_priority_chain :Chained(chain_base) PathPart('') Args(Int) { }
If you use a reference type constraint in CaptureArgs, it must be a type
like Tuple in L<Types::Standard> that allows us to determine the number of
args to match. Otherwise this will raise an error during startup.
See L<Catalyst::RouteMatching> for more.
=item Args
By default, endpoints receive the rest of the arguments in the path. You
can tell Catalyst through C<:Args> explicitly how many arguments your
endpoint expects, just like you can with C<:CaptureArgs>. Note that this
also affects whether this chain is invoked on a request. A chain with an
endpoint specifying one argument will only match if exactly one argument
exists in the path.
You can specify an exact number of arguments like C<:Args(3)>, including
C<0>. If you just say C<:Args> without any arguments, it is the same as
leaving it out altogether: The chain is matched regardless of the number
of path parts after the endpoint.
Just as with C<:CaptureArgs>, the arguments get passed to the action in
C<@_> after the context object. They can also be reached through
C<$c-E<gt>request-E<gt>arguments>.
You should see 'Args' in L<Catalyst::Controller> for more details on using
type constraints in your Args declarations.
=back
=head2 Auto actions, dispatching and forwarding
Note that the list of C<auto> actions called depends on the private path
of the endpoint of the chain, not on the chained actions way. The
C<auto> actions will be run before the chain dispatching begins. In
every other aspect, C<auto> actions behave as documented.
The C<forward>ing to other actions does just what you would expect. i.e.
only the target action is run. The actions that that action is chained
to are not run.
If you C<detach> out of a chain, the rest of the chain will not get
called after the C<detach>.
=head2 match_captures
A method which can optionally be implemented by actions to
stop chain matching.
See L<Catalyst::Action> for further details.
=head1 AUTHORS
Catalyst Contributors, see Catalyst.pm
=head1 COPYRIGHT
This library is free software. You can redistribute it and/or modify it under
the same terms as Perl itself.
=cut
1;
|