Updated Internals.pod

[catagits/Catalyst-Runtime.git] / lib / Catalyst / Manual / Internals.pod

diff --git a/lib/Catalyst/Manual/Internals.pod b/lib/Catalyst/Manual/Internals.pod
index ac939f4..41efa22 100644 (file)
--- a/lib/Catalyst/Manual/Internals.pod
+++ b/lib/Catalyst/Manual/Internals.pod
@@ -4,28 +4,81 @@ Catalyst::Manual::Internals - Catalyst Internals
 
 =head1 DESCRIPTION
 
-=head2 Lifecycle
+This document provides an overview of the internals of
+Catalyst.  As Catalyst is still developing rapidly, details
+may become out of date: please treat this as a guide, and
+look at the source for the last word.
 
-These are the steps of a Catalyst request, every step can be overloaded to
+The coverage is split into initialization and request lifecycle.
+
+=head2 Initialization
+
+Catalyst initializes itself in two stages (I may be wrong in some of
+the details here - AF):
+
+=over 4
+
+=item 1
+
+When the Catalyst module is imported in the main application
+module it evaluates any options (C<-Debug>, C<-Engine=XXX>)
+and loads any specified plugins, making the application module
+inherit from the plugin classes. It also sets up a default log
+object and ensures that the application module inherits from
+C<Catalyst> and from the selected specialized Engine module.
+
+=item 2
+
+When the application module makes the first call to C<< __PACKAGE__->action() >>
+(implemented in C<Catalyst::Engine>), Catalyst automatically loads all
+components it finds in the C<$class::Controller>, C<$class::C>,
+C<$class::Model>, C<$class::M>, C<$class::View> and C<$class::V>
+namespaces (using C<Module::Pluggable::Fast>).  A table of actions is built up
+and added to on subsequent calls to C<action()>.
+
+=back
+
+
+=head2 Request Lifecycle
+
+For each request Catalyst builds a I<context> object, which includes
+information about the request, and then searches the action table for matching
+actions.  
+
+The handling of a request can be divided into three stages: preparation of the
+context, processing of the request, and finalization of the response.  These
+are the steps of a Catalyst request in detail; every step can be overloaded to
 extend Catalyst.
 
-    handler
+    handle_request
       prepare
         prepare_request
-        prepare_path
-        prepare_cookies
+        prepare_connection
+        prepare_query_parameters
         prepare_headers
+        prepare_cookies
+        prepare_path
+        prepare_body (unless parse_on_demand)
+          prepare_body_parameters
+          prepare_parameters
+          prepare_uploads
         prepare_action
-        prepare_parameters
-        prepare_uploads
-      process
+      dispatch
       finalize
+        finalize_uploads
+        finalize_error (if one happened)
         finalize_headers
-        finalize_output
+          finalize_cookies
+        finalize_body
+
+These steps are normally overloaded from engine classes, and may also be
+extended by plugins.  Extending means using multiple inheritance with L<NEXT>.
+
+The specialized engine classes populate the Catalyst request object with
+information from the underlying layer (C<Apache::Request> or C<CGI::Simple>)
+during the prepare phase, then push the generated response information down to
+the underlying layer during the finalize phase.
 
-These steps are normally overloaded from engine classes, and extended by
-plugins.
-Extending means using multiple inheritance with L<NEXT>.
 
 =head1 AUTHOR