Fix arg constraints example in doc

[catagits/Catalyst-Runtime.git] / lib / Catalyst / RouteMatching.pod

diff --git a/lib/Catalyst/RouteMatching.pod b/lib/Catalyst/RouteMatching.pod
index e91b560..e5f567c 100644 (file)
--- a/lib/Catalyst/RouteMatching.pod
+++ b/lib/Catalyst/RouteMatching.pod
@@ -10,6 +10,73 @@ This is a WIP document intended to help people understand the logic that L<Catal
 uses to determine how to match in incoming request to an action (or action chain)
 in a controller.
 
+=head2 Request to Controller/Action Matching
+
+L<Catalyst> maps requests to action using a 'longest path wins' approach.  That means
+that if the request is '/foo/bar/baz' That means the action 'baz' matches:
+
+    package MyApp::Controller::Foo;
+
+    use Moose;
+    use MooseX::MethodAttributes
+
+    extends 'Catalyst::Controller';
+
+    sub bar :Path('bar') Args(1) { ...}
+    sub baz :Path('bar/baz') Args(0) { ... }
+
+Path length matches take precidence over all other types of matches (included HTTP
+Method, Scheme, etc.).  The same holds true for Chained actions.  Generally the
+chain that matches the most PathParts wins.
+
+=head2 Args(N) versus Args
+
+'Args' matches any number of args.  Because this functions as a sort of catchall, we
+treat 'Args' as the lowest precedence of any Args(N) when N is 0 to infinity.  An
+action with 'Args' always get the last chance to match.
+
+=head2 When two or more actions match a given Path
+
+Sometimes two or more actions match the same path and all have the same pathpart
+length.  For example:
+
+    package MyApp::Controller::Root;
+
+    use Moose;
+    use MooseX::MethodAttributes
+
+    extends 'Catalyst::Controller';
+
+    sub root :Chained(/) CaptureArgs(0) { }
+
+      sub one :Chained(root) PathPart('') Args(0) { }
+      sub two :Chained(root) PathPart('') Args(0) { }
+      sub three :Chained(root) PathPart('') Args(0) { }
+
+    __PACKAGE__->meta->make_immutable;
+
+In this case the last defined action wins (for the example that is action 'three').
+
+This is most common to happen when you are using action matching beyond paths, such as
+when using method matching:
+
+    package MyApp::Controller::Root;
+
+    use Moose;
+    use MooseX::MethodAttributes
+
+    extends 'Catalyst::Controller';
+
+    sub root :Chained(/) CaptureArgs(0) { }
+
+      sub any :Chained(root) PathPart('') Args(0) { }
+      sub get :GET Chained(root) PathPart('') Args(0) { }
+
+    __PACKAGE__->meta->make_immutable;
+
+In the above example GET /root could match both actions.  In this case you should define
+your 'catchall' actions higher in the controller.
+
 =head2 Type Constraints in Args and Capture Args
 
 Beginning in Version 5.90090+ you may use L<Moose>, L<MooseX::Types> or L<Type::Tiny>
@@ -20,10 +87,11 @@ is a simple example:
 
     use Moose;
     use MooseX::MethodAttributes;
+    use MooseX::Types::Moose qw(Int);
 
     extends 'Catalyst::Controller';
 
-    sub find :Path('') Args('Int') {
+    sub find :Path('') Args(Int) {
       my ($self, $c, $int) = @_;
     }
 
@@ -208,10 +276,6 @@ parent controller or consumed role.
 
 Please note that your declared type constraint names will now appear in the debug console.
 
-=head1 Conclusion
-
-    TBD
-
 =head1 Author
 
 John Napiorkowski L<jjnapiork@cpan.org|email:jjnapiork@cpan.org>