package Catalyst::DispatchType::Chained;
-use strict;
-use base qw/Catalyst::DispatchType/;
+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 SYNOPSIS
-See L<Catalyst>.
+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)
sub list {
my ( $self, $c ) = @_;
- return unless $self->{endpoints};
+ 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(
- [ 35, 'Path Spec' ], [ 36, 'Private' ]
- );
+ [ $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} }
+ @{ $self->_endpoints }
) {
- my $args = $endpoint->attributes->{Args}->[0];
+ my $args = $endpoint->list_extra_info->{Args};
my @parts = (defined($args) ? (("*") 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->attributes->{CaptureArgs}) {
- unshift(@parts, (("*") x $cap->[0]));
+ if (my $cap = $curr->list_extra_info->{CaptureArgs}) {
+ unshift(@parts, (("*") x $cap));
}
- if (my $pp = $curr->attributes->{PartPath}) {
+ 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};
+ $curr = $self->_actions->{$parent};
unshift(@parents, $curr) if $curr;
}
- next ENDPOINT unless $parent eq '/'; # skip dangling action
+ if ($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 (my $cap = $p->attributes->{CaptureArgs}) {
- $name .= ' ('.$cap->[0].')';
+
+ if (defined(my $extra = $self->_list_extra_http_methods($p))) {
+ $name = "${extra} ${name}";
+ }
+ if (defined(my $cap = $p->list_extra_info->{CaptureArgs})) {
+ $name .= ' ('.$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, [ '', $name ]);
}
- push(@rows, [ '', (@rows ? "=> " : '')."/${endpoint}" ]);
- $rows[0][0] = join('/', '', @parts);
+ push(@rows, [ '', (@rows ? "=> " : '').($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 Path Part actions:\n" . $paths->draw );
+ $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, $path )
-Matt is an idiot and hasn't documented this yet.
+Calls C<recurse_match> to see if a chain matches the C<$path>.
=cut
sub match {
my ( $self, $c, $path ) = @_;
- return 0 if @{$c->req->args};
+ my $request = $c->request;
+ return 0 if @{$request->args};
my @parts = split('/', $path);
- my ($chain, $captures) = $self->recurse_match($c, '/', \@parts);
+ 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);
- $c->req->action("/${action}");
- $c->req->match("/${action}");
- $c->req->captures($captures);
+ $request->action("/${action}");
+ $request->match("/${action}");
+ $request->captures($captures);
$c->action($action);
$c->namespace( $action->namespace );
=head2 $self->recurse_match( $c, $parent, \@path_parts )
-Matt is an idiot and hasn't documented this yet.
+Recursive search for a matching chain.
=cut
sub recurse_match {
my ( $self, $c, $parent, $path_parts ) = @_;
- my $children = $self->{children_of}{$parent};
+ 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) {
my @try_actions = @{$children->{$try_part}};
TRY_ACTION: foreach my $action (@try_actions) {
if (my $capture_attr = $action->attributes->{CaptureArgs}) {
+ my $capture_count = $capture_attr->[0] || 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_attr->[0]));
+ push(@captures, splice(@parts, 0, $capture_count));
+
+ # check if the action may fit, depending on a given test by the app
+ if ($action->can('match_captures')) { next TRY_ACTION unless $action->match_captures($c, \@captures) }
# try the remaining parts against children of this action
- my ($actions, $captures) = $self->recurse_match(
+ my ($actions, $captures, $action_parts, $n_pathparts) = $self->recurse_match(
$c, '/'.$action->reverse, \@parts
);
- if ($actions) {
- return [ $action, @$actions ], [ @captures, @$captures ];
+ # No best action currently
+ # OR The action has less parts
+ # OR The action has equal parts but less captured data (ergo more defined)
+ if ($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 {
+ }
+ else {
{
local $c->req->{arguments} = [ @{$c->req->args}, @parts ];
next TRY_ACTION unless $action->match($c);
}
- push(@{$c->req->args}, @parts);
- return [ $action ], [ ];
+ my $args_attr = $action->attributes->{Args}->[0];
+ 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_attr eq "0")){
+ $best_action = {
+ actions => [ $action ],
+ captures=> [],
+ parts => \@parts,
+ n_pathparts => scalar(@pathparts),
+ };
+ }
}
}
}
+ return @$best_action{qw/actions captures parts n_pathparts/} if $best_action;
return ();
}
=head2 $self->register( $c, $action )
-Matt is an idiot and hasn't documented this yet.
+Calls register_path for every Path attribute for the given $action.
=cut
+sub _check_args_attr {
+ my ( $self, $action, $name ) = @_;
+
+ return unless exists $action->attributes->{$name};
+
+ if (@{$action->attributes->{$name}} > 1) {
+ Catalyst::Exception->throw(
+ "Multiple $name attributes not supported registering " . $action->reverse()
+ );
+ }
+ my $args = $action->attributes->{$name}->[0];
+ if (defined($args) and not (
+ Scalar::Util::looks_like_number($args) and
+ int($args) == $args and $args >= 0
+ )) {
+ require Data::Dumper;
+ local $Data::Dumper::Terse = 1;
+ local $Data::Dumper::Indent = 0;
+ $args = Data::Dumper::Dumper($args);
+ Catalyst::Exception->throw(
+ "Invalid $name($args) for action " . $action->reverse() .
+ " (use '$name' or '$name(<number>)')"
+ );
+ }
+}
+
sub register {
my ( $self, $c, $action ) = @_;
return 0 unless @chained_attr;
- if (@chained_attr > 2) {
+ if (@chained_attr > 1) {
Catalyst::Exception->throw(
"Multiple Chained attributes not supported registering ${action}"
);
}
+ my $chained_to = $chained_attr[0];
- my $parent = $chained_attr[0];
-
- if (defined($parent) && length($parent)) {
- if ($parent eq '.') {
- $parent = '/'.$action->namespace;
- } elsif ($parent !~ m/^\//) {
- $parent = '/'.join('/', $action->namespace, $parent);
- }
- } else {
- $parent = '/'
- }
-
- $action->attributes->{Chained} = [ $parent ];
+ Catalyst::Exception->throw(
+ "Actions cannot chain to themselves registering /${action}"
+ ) if ($chained_to eq '/' . $action);
- my $children = ($self->{children_of}{$parent} ||= {});
+ my $children = ($self->_children_of->{ $chained_to } ||= {});
my @path_part = @{ $action->attributes->{PathPart} || [] };
$part = $path_part[0];
} elsif (@path_part > 1) {
Catalyst::Exception->throw(
- "Multiple PathPart attributes not supported registering ${action}"
+ "Multiple PathPart attributes not supported registering " . $action->reverse()
);
}
- $action->attributes->{PartPath} = [ $part ];
+ if ($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;
- unshift(@{ $children->{$part} ||= [] }, $action);
+ foreach my $name (qw(Args CaptureArgs)) {
+ $self->_check_args_attr($action, $name);
+ }
- ($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);
+ unshift(@{ $self->_endpoints }, $action);
}
return 1;
=head2 $self->uri_for_action($action, $captures)
-Matt is an idiot and hasn't documented this yet.
+Get the URI part for the action, using C<$captures> to fill
+the capturing parts.
=cut
my ( $self, $action, $captures ) = @_;
return undef unless ($action->attributes->{Chained}
- && $action->attributes->{Args});
+ && !$action->attributes->{CaptureArgs});
my @parts = ();
my @captures = @$captures;
my $curr = $action;
while ($curr) {
if (my $cap = $curr->attributes->{CaptureArgs}) {
- return undef unless @captures >= $cap->[0]; # not enough captures
- unshift(@parts, splice(@captures, -$cap->[0]));
+ return undef unless @captures >= ($cap->[0]||0); # not enough captures
+ if ($cap->[0]) {
+ unshift(@parts, splice(@captures, -$cap->[0]));
+ }
}
- if (my $pp = $curr->attributes->{PartPath}) {
+ if (my $pp = $curr->attributes->{PathPart}) {
unshift(@parts, $pp->[0])
- if (defined $pp->[0] && length $pp->[0]);
+ if (defined($pp->[0]) && length($pp->[0]));
}
$parent = $curr->attributes->{Chained}->[0];
- $curr = $self->{actions}{$parent};
+ $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]);
}
-=head1 AUTHOR
+__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.
+
+=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>.
+
+=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
-Matt S Trout <mst@shadowcatsystems.co.uk>
+Catalyst Contributors, see Catalyst.pm
=head1 COPYRIGHT
-This program is free software, you can redistribute it and/or modify it under
+This library is free software. You can redistribute it and/or modify it under
the same terms as Perl itself.
=cut
projects / catagits/Catalyst-Runtime.git / blobdiff