Catalyst.3pm

Langue: en

Version: 2010-07-28 (fedora - 01/12/10)

Section: 3 (Bibliothèques de fonctions)

Sommaire

NAME

Catalyst - The Elegant MVC Web Application Framework

SYNOPSIS

See the Catalyst::Manual distribution for comprehensive documentation and tutorials.
     # Install Catalyst::Devel for helpers and other development tools
     # use the helper to create a new application
     catalyst.pl MyApp
 
     # add models, views, controllers
     script/myapp_create.pl model MyDatabase DBIC::Schema create=static dbi:SQLite:/path/to/db
     script/myapp_create.pl view MyTemplate TT
     script/myapp_create.pl controller Search
 
     # built in testserver -- use -r to restart automatically on changes
     # --help to see all available options
     script/myapp_server.pl
 
     # command line testing interface
     script/myapp_test.pl /yada
 
     ### in lib/MyApp.pm
     use Catalyst qw/-Debug/; # include plugins here as well
 
     ### In lib/MyApp/Controller/Root.pm (autocreated)
     sub foo : Global { # called for /foo, /foo/1, /foo/1/2, etc.
         my ( $self, $c, @args ) = @_; # args are qw/1 2/ for /foo/1/2
         $c->stash->{template} = 'foo.tt'; # set the template
         # lookup something from db -- stash vars are passed to TT
         $c->stash->{data} =
           $c->model('Database::Foo')->search( { country => $args[0] } );
         if ( $c->req->params->{bar} ) { # access GET or POST parameters
             $c->forward( 'bar' ); # process another action
             # do something else after forward returns
         }
     }
 
     # The foo.tt TT template can use the stash data from the database
     [% WHILE (item = data.next) %]
         [% item.foo %]
     [% END %]
 
     # called for /bar/of/soap, /bar/of/soap/10, etc.
     sub bar : Path('/bar/of/soap') { ... }
 
     # called for all actions, from the top-most controller downwards
     sub auto : Private {
         my ( $self, $c ) = @_;
         if ( !$c->user_exists ) { # Catalyst::Plugin::Authentication
             $c->res->redirect( '/login' ); # require login
             return 0; # abort request and go immediately to end()
         }
         return 1; # success; carry on to next action
     }
 
     # called after all actions are finished
     sub end : Private {
         my ( $self, $c ) = @_;
         if ( scalar @{ $c->error } ) { ... } # handle errors
         return if $c->res->body; # already have a response
         $c->forward( 'MyApp::View::TT' ); # render template
     }
 
     ### in MyApp/Controller/Foo.pm
     # called for /foo/bar
     sub bar : Local { ... }
 
     # called for /blargle
     sub blargle : Global { ... }
 
     # an index action matches /foo, but not /foo/1, etc.
     sub index : Private { ... }
 
     ### in MyApp/Controller/Foo/Bar.pm
     # called for /foo/bar/baz
     sub baz : Local { ... }
 
     # first Root auto is called, then Foo auto, then this
     sub auto : Private { ... }
 
     # powerful regular expression paths are also possible
     sub details : Regex('^product/(\w+)/details$') {
         my ( $self, $c ) = @_;
         # extract the (\w+) from the URI
         my $product = $c->req->captures->[0];
     }
 
 

See Catalyst::Manual::Intro for additional information.

DESCRIPTION

Catalyst is a modern framework for making web applications without the pain usually associated with this process. This document is a reference to the main Catalyst application. If you are a new user, we suggest you start with Catalyst::Manual::Tutorial or Catalyst::Manual::Intro.

See Catalyst::Manual for more documentation.

Catalyst plugins can be loaded by naming them as arguments to the ``use Catalyst'' statement. Omit the "Catalyst::Plugin::" prefix from the plugin name, i.e., "Catalyst::Plugin::My::Module" becomes "My::Module".

     use Catalyst qw/My::Module/;
 
 

If your plugin starts with a name other than "Catalyst::Plugin::", you can fully qualify the name by using a unary plus:

     use Catalyst qw/
         My::Module
         +Fully::Qualified::Plugin::Name
     /;
 
 

Special flags like "-Debug" and "-Engine" can also be specified as arguments when Catalyst is loaded:

     use Catalyst qw/-Debug My::Module/;
 
 

The position of plugins and flags in the chain is important, because they are loaded in the order in which they appear.

The following flags are supported:

-Debug

Enables debug output. You can also force this setting from the system environment with CATALYST_DEBUG or <MYAPP>_DEBUG. The environment settings override the application, with <MYAPP>_DEBUG having the highest priority.

This sets the log level to 'debug' and enables full debug output on the error screen. If you only want the latter, see $c->debug.

-Engine

Forces Catalyst to use a specific engine. Omit the "Catalyst::Engine::" prefix of the engine name, i.e.:
     use Catalyst qw/-Engine=CGI/;
 
 

-Home

Forces Catalyst to use a specific home directory, e.g.:
     use Catalyst qw[-Home=/usr/mst];
 
 

This can also be done in the shell environment by setting either the "CATALYST_HOME" environment variable or "MYAPP_HOME"; where "MYAPP" is replaced with the uppercased name of your application, any ``::'' in the name will be replaced with underscores, e.g. MyApp::Web should use MYAPP_WEB_HOME. If both variables are set, the MYAPP_HOME one will be used.

If none of these are set, Catalyst will attempt to automatically detect the home directory. If you are working in a development envirnoment, Catalyst will try and find the directory containing either Makefile.PL, Build.PL or dist.ini. If the application has been installed into the system (i.e. you have done "make install"), then Catalyst will use the path to your application module, without the .pm extension (ie, /foo/MyApp if your application was installed at /foo/MyApp.pm)

-Log

     use Catalyst '-Log=warn,fatal,error';
 
 

Specifies a comma-delimited list of log levels.

-Stats

Enables statistics collection and reporting.
    use Catalyst qw/-Stats=1/;
 
 

You can also force this setting from the system environment with CATALYST_STATS or <MYAPP>_STATS. The environment settings override the application, with <MYAPP>_STATS having the highest priority.

Stats are also enabled if debugging is enabled.

METHODS

INFORMATION ABOUT THE CURRENT REQUEST

$c->action

Returns a Catalyst::Action object for the current action, which stringifies to the action name. See Catalyst::Action.

$c->namespace

Returns the namespace of the current action, i.e., the URI prefix corresponding to the controller of the current action. For example:
     # in Controller::Foo::Bar
     $c->namespace; # returns 'foo/bar';
 
 

$c->request

$c->req

Returns the current Catalyst::Request object, giving access to information about the current client request (including parameters, cookies, HTTP headers, etc.). See Catalyst::Request.

REQUEST FLOW HANDLING

$c->forward( $action [, \@arguments ] )

$c->forward( $class, $method, [, \@arguments ] )

Forwards processing to another action, by its private name. If you give a class name but no method, "process()" is called. You may also optionally pass arguments in an arrayref. The action will receive the arguments in @_ and "$c->req->args". Upon returning from the function, "$c->req->args" will be restored to the previous values.

Any data "return"ed from the action forwarded to, will be returned by the call to forward.

     my $foodata = $c->forward('/foo');
     $c->forward('index');
     $c->forward(qw/Model::DBIC::Foo do_stuff/);
     $c->forward('View::TT');
 
 

Note that forward implies an "eval { }" around the call (actually execute does), thus de-fatalizing all 'dies' within the called action. If you want "die" to propagate you need to do something like:

     $c->forward('foo');
     die join "\n", @{ $c->error } if @{ $c->error };
 
 

Or make sure to always return true values from your actions and write your code like this:

     $c->forward('foo') || return;
 
 

Another note is that "$c->forward" always returns a scalar because it actually returns $c->state which operates in a scalar context. Thus, something like:

     return @array;
 
 

in an action that is forwarded to is going to return a scalar, i.e. how many items are in that array, which is probably not what you want. If you need to return an array then return a reference to it, or stash it like so:

     $c->stash->{array} = \@array;
 
 

and access it from the stash.

$c->detach( $action [, \@arguments ] )

$c->detach( $class, $method, [, \@arguments ] )

$c->detach()

The same as forward, but doesn't return to the previous action when processing is finished.

When called with no arguments it escapes the processing chain entirely.

$c->visit( $action [, \@captures, \@arguments ] )

$c->visit( $class, $method, [, \@captures, \@arguments ] )

Almost the same as forward, but does a full dispatch, instead of just calling the new $action / "$class->$method". This means that "begin", "auto" and the method you go to are called, just like a new request.

In addition both "$c->action" and "$c->namespace" are localized. This means, for example, that "$c->action" methods such as name, class and reverse return information for the visited action when they are invoked within the visited action. This is different from the behavior of forward, which continues to use the $c->action object from the caller action even when invoked from the callee.

"$c->stash" is kept unchanged.

In effect, visit allows you to ``wrap'' another action, just as it would have been called by dispatching from a URL, while the analogous go allows you to transfer control to another action as if it had been reached directly from a URL.

$c->go( $action [, \@captures, \@arguments ] )

$c->go( $class, $method, [, \@captures, \@arguments ] )

The relationship between "go" and visit is the same as the relationship between forward and detach. Like "$c->visit", "$c->go" will perform a full dispatch on the specified action or method, with localized "$c->action" and "$c->namespace". Like "detach", "go" escapes the processing of the current request chain on completion, and does not return to its caller.

$c->response

$c->res

Returns the current Catalyst::Response object, see there for details.

$c->stash

Returns a hashref to the stash, which may be used to store data and pass it between components during a request. You can also set hash keys by passing arguments. The stash is automatically sent to the view. The stash is cleared at the end of a request; it cannot be used for persistent storage (for this you must use a session; see Catalyst::Plugin::Session for a complete system integrated with Catalyst).
     $c->stash->{foo} = $bar;
     $c->stash( { moose => 'majestic', qux => 0 } );
     $c->stash( bar => 1, gorch => 2 ); # equivalent to passing a hashref
 
     # stash is automatically passed to the view for use in a template
     $c->forward( 'MyApp::View::TT' );
 
 

$c->error

$c->error($error, ...)

$c->error($arrayref)

Returns an arrayref containing error messages. If Catalyst encounters an error while processing a request, it stores the error in $c->error. This method should only be used to store fatal error messages.
     my @error = @{ $c->error };
 
 

Add a new error.

     $c->error('Something bad happened');
 
 

$c->state

Contains the return value of the last executed action. Note that << $c->state >> operates in a scalar context which means that all values it returns are scalar.

$c->clear_errors

Clear errors. You probably don't want to clear the errors unless you are implementing a custom error screen.

This is equivalent to running

     $c->error(0);
 
 

COMPONENT ACCESSORS

$c->controller($name)

Gets a Catalyst::Controller instance by name.
     $c->controller('Foo')->do_stuff;
 
 

If the name is omitted, will return the controller for the dispatched action.

If you want to search for controllers, pass in a regexp as the argument.

     # find all controllers that start with Foo
     my @foo_controllers = $c->controller(qr{^Foo});
 
 

$c->model($name)

Gets a Catalyst::Model instance by name.
     $c->model('Foo')->do_stuff;
 
 

Any extra arguments are directly passed to ACCEPT_CONTEXT.

If the name is omitted, it will look for
 - a model object in $c->stash->{current_model_instance}, then
 - a model name in $c->stash->{current_model}, then
 - a config setting 'default_model', or
 - check if there is only one model, and return it if that's the case.

If you want to search for models, pass in a regexp as the argument.

     # find all models that start with Foo
     my @foo_models = $c->model(qr{^Foo});
 
 

$c->view($name)

Gets a Catalyst::View instance by name.
     $c->view('Foo')->do_stuff;
 
 

Any extra arguments are directly passed to ACCEPT_CONTEXT.

If the name is omitted, it will look for
 - a view object in $c->stash->{current_view_instance}, then
 - a view name in $c->stash->{current_view}, then
 - a config setting 'default_view', or
 - check if there is only one view, and return it if that's the case.

If you want to search for views, pass in a regexp as the argument.

     # find all views that start with Foo
     my @foo_views = $c->view(qr{^Foo});
 
 

$c->controllers

Returns the available names which can be passed to $c->controller

$c->models

Returns the available names which can be passed to $c->model

$c->views

Returns the available names which can be passed to $c->view

$c->comp($name)

$c->component($name)

Gets a component object by name. This method is not recommended, unless you want to get a specific component by full class. "$c->controller", "$c->model", and "$c->view" should be used instead.

If $name is a regexp, a list of components matched against the full component name will be returned.

If Catalyst can't find a component by name, it will fallback to regex matching by default. To disable this behaviour set disable_component_resolution_regex_fallback to a true value.

     __PACKAGE__->config( disable_component_resolution_regex_fallback => 1 );
 
 

CLASS DATA AND HELPER CLASSES

$c->config

Returns or takes a hashref containing the application's configuration.
     __PACKAGE__->config( { db => 'dsn:SQLite:foo.db' } );
 
 

You can also use a "YAML", "XML" or Config::General config file like "myapp.conf" in your applications home directory. See Catalyst::Plugin::ConfigLoader.

Cascading configuration

The config method is present on all Catalyst components, and configuration will be merged when an application is started. Configuration loaded with Catalyst::Plugin::ConfigLoader takes precedence over other configuration, followed by configuration in your top level "MyApp" class. These two configurations are merged, and then configuration data whose hash key matches a component name is merged with configuration for that component.

The configuration for a component is then passed to the "new" method when a component is constructed.

For example:

     MyApp->config({ 'Model::Foo' => { bar => 'baz', overrides => 'me' } });
     MyApp::Model::Foo->config({ quux => 'frob', overrides => 'this' });
 
 

will mean that "MyApp::Model::Foo" receives the following data when constructed:

     MyApp::Model::Foo->new({
         bar => 'baz',
         quux => 'frob',
         overrides => 'me',
     });
 
 

It's common practice to use a Moose attribute on the receiving component to access the config value.

     package MyApp::Model::Foo;
 
     use Moose;
 
     # this attr will receive 'baz' at construction time
     has 'bar' => ( 
         is  => 'rw',
         isa => 'Str',
     );
 
 

You can then get the value 'baz' by calling $c->model('Foo')->bar

$c->log

Returns the logging object instance. Unless it is already set, Catalyst sets this up with a Catalyst::Log object. To use your own log class, set the logger with the "__PACKAGE__->log" method prior to calling "__PACKAGE__->setup".
  __PACKAGE__->log( MyLogger->new );
  __PACKAGE__->setup;
 
 

And later:

     $c->log->info( 'Now logging with my own logger!' );
 
 

Your log class should implement the methods described in Catalyst::Log.

$c->debug

Returns 1 if debug mode is enabled, 0 otherwise.

You can enable debug mode in several ways:

By calling myapp_server.pl with the -d flag
With the environment variables MYAPP_DEBUG, or CATALYST_DEBUG
The -Debug option in your MyApp.pm
By declaring sub debug { 1 } in your MyApp.pm.

The first three also set the log level to 'debug'.

Calling "$c->debug(1)" has no effect.

$c->dispatcher

Returns the dispatcher instance. See Catalyst::Dispatcher.

$c->engine

Returns the engine instance. See Catalyst::Engine.

UTILITY METHODS

$c->path_to(@path)

Merges @path with "$c->config->{home}" and returns a Path::Class::Dir object. Note you can usually use this object as a filename, but sometimes you will have to explicitly stringify it yourself by calling the "->stringify" method.

For example:

     $c->path_to( 'db', 'sqlite.db' );
 
 

$c->plugin( $name, $class, @args )

Helper method for plugins. It creates a class data accessor/mutator and loads and instantiates the given class.
     MyApp->plugin( 'prototype', 'HTML::Prototype' );
 
     $c->prototype->define_javascript_functions;
 
 

Note: This method of adding plugins is deprecated. The ability to add plugins like this will be removed in a Catalyst 5.81. Please do not use this functionality in new code.

MyApp->setup

Initializes the dispatcher and engine, loads any plugins, and loads the model, view, and controller components. You may also specify an array of plugins to load here, if you choose to not load them in the "use Catalyst" line.
     MyApp->setup;
     MyApp->setup( qw/-Debug/ );
 
 

$app->setup_finalize

A hook to attach modifiers to. This method does not do anything except set the "setup_finished" accessor.

Applying method modifiers to the "setup" method doesn't work, because of quirky thingsdone for plugin setup.

Example:

     after setup_finalize => sub {
         my $app = shift;
 
         ## do stuff here..
     };
 
 

$c->uri_for( $path?, @args?, \%query_values? )

$c->uri_for( $action, \@captures?, @args?, \%query_values? )

Constructs an absolute URI object based on the application root, the provided path, and the additional arguments and query parameters provided. When used as a string, provides a textual URI.

If no arguments are provided, the URI for the current action is returned. To return the current action and also provide @args, use "$c->uri_for( $c->action, @args )".

If the first argument is a string, it is taken as a public URI path relative to "$c->namespace" (if it doesn't begin with a forward slash) or relative to the application root (if it does). It is then merged with "$c->request->base"; any @args are appended as additional path components; and any %query_values are appended as "?foo=bar" parameters.

If the first argument is a Catalyst::Action it represents an action which will have its path resolved using "$c->dispatcher->uri_for_action". The optional "\@captures" argument (an arrayref) allows passing the captured variables that are needed to fill in the paths of Chained and Regex actions; once the path is resolved, "uri_for" continues as though a path was provided, appending any arguments or parameters and creating an absolute URI.

The captures for the current request can be found in "$c->request->captures", and actions can be resolved using "Catalyst::Controller->action_for($name)". If you have a private action path, use "$c->uri_for_action" instead.

   # Equivalent to $c->req->uri
   $c->uri_for($c->action, $c->req->captures,
       @{ $c->req->args }, $c->req->params);
 
   # For the Foo action in the Bar controller
   $c->uri_for($c->controller('Bar')->action_for('Foo'));
 
   # Path to a static resource
   $c->uri_for('/static/images/logo.png');
 
 

$c->uri_for_action( $path, \@captures?, @args?, \%query_values? )

$c->uri_for_action( $action, \@captures?, @args?, \%query_values? )

$path
A private path to the Catalyst action you want to create a URI for.

This is a shortcut for calling "$c->dispatcher->get_action_by_path($path)" and passing the resulting $action and the remaining arguments to "$c->uri_for".

You can also pass in a Catalyst::Action object, in which case it is passed to "$c->uri_for".

Note that although the path looks like a URI that dispatches to the wanted action, it is not a URI, but an internal path to that action.

For example, if the action looks like:

  package MyApp::Controller::Users;
 
  sub lst : Path('the-list') {}
 
 

You can use:

  $c->uri_for_action('/users/lst')
 
 

and it will create the URI /users/the-list.

$c->welcome_message

Returns the Catalyst welcome HTML page.

INTERNAL METHODS

These methods are not meant to be used by end users.

$c->components

Returns a hash of components.

$c->context_class

Returns or sets the context class.

$c->counter

Returns a hashref containing coderefs and execution counts (needed for deep recursion detection).

$c->depth

Returns the number of actions on the current internal execution stack.

$c->dispatch

Dispatches a request to actions.

$c->dispatcher_class

Returns or sets the dispatcher class.

$c->dump_these

Returns a list of 2-element array references (name, structure) pairs that will be dumped on the error page in debug mode.

$c->engine_class

Returns or sets the engine class.

$c->execute( $class, $coderef )

Execute a coderef in given class and catch exceptions. Errors are available via $c->error.

$c->finalize

Finalizes the request.

$c->finalize_body

Finalizes body.

$c->finalize_cookies

Finalizes cookies.

$c->finalize_error

Finalizes error.

$c->finalize_headers

Finalizes headers.

$c->finalize_output

An alias for finalize_body.

$c->finalize_read

Finalizes the input after reading is complete.

$c->finalize_uploads

Finalizes uploads. Cleans up any temporary files.

$c->get_action( $action, $namespace )

Gets an action in a given namespace.

$c->get_actions( $action, $namespace )

Gets all actions of a given name in a namespace and all parent namespaces.

$app->handle_request( @arguments )

Called to handle each HTTP request.

$c->prepare( @arguments )

Creates a Catalyst context from an engine-specific request (Apache, CGI, etc.).

$c->prepare_action

Prepares action. See Catalyst::Dispatcher.

$c->prepare_body

Prepares message body.

$c->prepare_body_chunk( $chunk )

Prepares a chunk of data before sending it to HTTP::Body.

See Catalyst::Engine.

$c->prepare_body_parameters

Prepares body parameters.

$c->prepare_connection

Prepares connection.

$c->prepare_cookies

Prepares cookies.

$c->prepare_headers

Prepares headers.

$c->prepare_parameters

Prepares parameters.

$c->prepare_path

Prepares path and base.

$c->prepare_query_parameters

Prepares query parameters.

$c->log_request

Writes information about the request to the debug logs. This includes:
*
Request method, path, and remote IP address
*
Query keywords (see ``query_keywords'' in Catalyst::Request)
*
Request parameters
*
File uploads

$c->log_response

Writes information about the response to the debug logs by calling "$c->log_response_status_line" and "$c->log_response_headers".

$c->log_response_status_line($response)

Writes one line of information about the response to the debug logs. This includes:
*
Response status code
*
Content-Type header (if present)
*
Content-Length header (if present)

$c->log_response_headers($headers);

Hook method which can be wrapped by plugins to log the responseheaders. No-op in the default implementation.

$c->log_request_parameters( query => {}, body => {} )

Logs request parameters to debug logs

$c->log_request_uploads

Logs file uploads included in the request to the debug logs. The parameter name, filename, file type, and file size are all included in the debug logs.

$c->log_request_headers($headers);

Hook method which can be wrapped by plugins to log the request headers. No-op in the default implementation.

$c->log_headers($type => $headers)

Logs HTTP::Headers (either request or response) to the debug logs.

$c->prepare_read

Prepares the input for reading.

$c->prepare_request

Prepares the engine request.

$c->prepare_uploads

Prepares uploads.

$c->prepare_write

Prepares the output for writing.

$c->request_class

Returns or sets the request class.

$c->response_class

Returns or sets the response class.

$c->read( [$maxlength] )

Reads a chunk of data from the request body. This method is designed to be used in a while loop, reading $maxlength bytes on every call. $maxlength defaults to the size of the request if not specified.

You have to set "MyApp->config(parse_on_demand => 1)" to use this directly.

Warning: If you use read(), Catalyst will not process the body, so you will not be able to access POST parameters or file uploads via $c->request. You must handle all body parsing yourself.

$c->run

Starts the engine.

$c->set_action( $action, $code, $namespace, $attrs )

Sets an action in a given namespace.

$c->setup_actions($component)

Sets up actions for a component.

$c->setup_components

This method is called internally to set up the application's components.

It finds modules by calling the locate_components method, expands them to package names with the expand_component_module method, and then installs each component into the application.

The "setup_components" config option is passed to both of the above methods.

Installation of each component is performed by the setup_component method, below.

$c->locate_components( $setup_component_config )

This method is meant to provide a list of component modules that should be setup for the application. By default, it will use Module::Pluggable.

Specify a "setup_components" config option to pass additional options directly to Module::Pluggable. To add additional search paths, specify a key named "search_extra" as an array reference. Items in the array beginning with "::" will have the application class name prepended to them.

$c->expand_component_module( $component, $setup_component_config )

Components found by "locate_components" will be passed to this method, which is expected to return a list of component (package) names to be set up.

$c->setup_component

$c->setup_dispatcher

Sets up dispatcher.

$c->setup_engine

Sets up engine.

$c->setup_home

Sets up the home directory.

$c->setup_log

Sets up log by instantiating a Catalyst::Log object and passing it to "log()". Pass in a comma-delimited list of levels to set the log to.

This method also installs a "debug" method that returns a true value into the catalyst subclass if the ``debug'' level is passed in the comma-delimited list, or if the $CATALYST_DEBUG environment variable is set to a true value.

Note that if the log has already been setup, by either a previous call to "setup_log" or by a call such as "__PACKAGE__->log( MyLogger->new )", that this method won't actually set up the log object.

$c->setup_plugins

Sets up plugins.

$c->setup_stats

Sets up timing statistics class.

$c->registered_plugins

Returns a sorted list of the plugins which have either been stated in the import list or which have been added via "MyApp->plugin(@args);".

If passed a given plugin name, it will report a boolean value indicating whether or not that plugin is loaded. A fully qualified name is required if the plugin name does not begin with "Catalyst::Plugin::".

  if ($c->registered_plugins('Some::Plugin')) {
      ...
  }
 
 

$c->stack

Returns an arrayref of the internal execution stack (actions that are currently executing).

$c->stats

Returns the current timing statistics object. By default Catalyst uses Catalyst::Stats, but can be set otherwise with stats_class.

Even if -Stats is not enabled, the stats object is still available. By enabling it with " $c-"stats->enabled(1) >, it can be used to profile explicitly, although MyApp.pm still won't profile nor output anything by itself.

$c->stats_class

Returns or sets the stats (timing statistics) class. Catalyst::Stats is used by default.

$c->use_stats

Returns 1 when stats collection is enabled.

Note that this is a static method, not an accessor and should be overridden by declaring "sub use_stats { 1 }" in your MyApp.pm, not by calling "$c->use_stats(1)".

$c->write( $data )

Writes $data to the output stream. When using this method directly, you will need to manually set the "Content-Length" header to the length of your output data, if known.

version

Returns the Catalyst version number. Mostly useful for ``powered by'' messages in template systems.

CONFIGURATION

There are a number of 'base' config variables which can be set:
*
"default_model" - The default model picked if you say "$c->model". See ``$c->model($name)''.
*
"default_view" - The default view to be rendered or returned when "$c->view" is called. See ``$c->view($name)''.
*
"disable_component_resolution_regex_fallback" - Turns off the deprecated component resolution functionality so that if any of the component methods (e.g. "$c->controller('Foo')") are called then regex search will not be attempted on string values and instead "undef" will be returned.
*
"home" - The application home directory. In an uninstalled application, this is the top level application directory. In an installed application, this will be the directory containing "MyApp.pm".
*
"ignore_frontend_proxy" - See ``PROXY SUPPORT''
*
"name" - The name of the application in debug messages and the debug and welcome screens
*
"parse_on_demand" - The request body (for example file uploads) will not be parsed until it is accessed. This allows you to (for example) check authentication (and reject the upload) before actually recieving all the data. See ``ON-DEMAND PARSER''
*
"root" - The root directory for templates. Usually this is just a subdirectory of the home directory, but you can set it to change the templates to a different directory.
*
"search_extra" - Array reference passed to Module::Pluggable to for additional namespaces from which components will be loaded (and constructed and stored in "$c->components").
*
"show_internal_actions" - If true, causes internal actions such as "_DISPATCH" to be shown in hit debug tables in the test server.
*
"use_request_uri_for_path" - Controlls if the "REQUEST_URI" or "PATH_INFO" environment variable should be used for determining the request path. See ``PATH DECODING'' in Catalyst::Engine::CGI for more information.
*
"using_frontend_proxy" - See ``PROXY SUPPORT''.

INTERNAL ACTIONS

Catalyst uses internal actions like "_DISPATCH", "_BEGIN", "_AUTO", "_ACTION", and "_END". These are by default not shown in the private action table, but you can make them visible with a config parameter.
     MyApp->config(show_internal_actions => 1);
 
 

ON-DEMAND PARSER

The request body is usually parsed at the beginning of a request, but if you want to handle input yourself, you can enable on-demand parsing with a config parameter.
     MyApp->config(parse_on_demand => 1);
 
 

PROXY SUPPORT

Many production servers operate using the common double-server approach, with a lightweight frontend web server passing requests to a larger backend server. An application running on the backend server must deal with two problems: the remote user always appears to be 127.0.0.1 and the server's hostname will appear to be "localhost" regardless of the virtual host that the user connected through.

Catalyst will automatically detect this situation when you are running the frontend and backend servers on the same machine. The following changes are made to the request.

     $c->req->address is set to the user's real IP address, as read from
     the HTTP X-Forwarded-For header.
 
     The host value for $c->req->base and $c->req->uri is set to the real
     host, as read from the HTTP X-Forwarded-Host header.
 
 

Additionally, you may be running your backend application on an insecure connection (port 80) while your frontend proxy is running under SSL. If there is a discrepancy in the ports, use the HTTP header "X-Forwarded-Port" to tell Catalyst what port the frontend listens on. This will allow all URIs to be created properly.

In the case of passing in:

     X-Forwarded-Port: 443
 
 

All calls to "uri_for" will result in an https link, as is expected.

Obviously, your web server must support these headers for this to work.

In a more complex server farm environment where you may have your frontend proxy server(s) on different machines, you will need to set a configuration option to tell Catalyst to read the proxied data from the headers.

     MyApp->config(using_frontend_proxy => 1);
 
 

If you do not wish to use the proxy support at all, you may set:

     MyApp->config(ignore_frontend_proxy => 1);
 
 

THREAD SAFETY

Catalyst has been tested under Apache 2's threading "mpm_worker", "mpm_winnt", and the standalone forking HTTP server on Windows. We believe the Catalyst core to be thread-safe.

If you plan to operate in a threaded environment, remember that all other modules you are using must also be thread-safe. Some modules, most notably DBD::SQLite, are not thread-safe.

SUPPORT

IRC:
     Join #catalyst on irc.perl.org.
 
 

Mailing Lists:

     http://lists.scsys.co.uk/cgi-bin/mailman/listinfo/catalyst
     http://lists.scsys.co.uk/cgi-bin/mailman/listinfo/catalyst-dev
 
 

Web:

     http://catalyst.perl.org
 
 

Wiki:

     http://dev.catalyst.perl.org
 
 

SEE ALSO

Task::Catalyst - All you need to start with Catalyst

Catalyst::Manual - The Catalyst Manual

Catalyst::Component, Catalyst::Controller - Base classes for components

Catalyst::Engine - Core engine

Catalyst::Log - Log class.

Catalyst::Request - Request object

Catalyst::Response - Response object

Catalyst::Test - The test suite.

PROJECT FOUNDER

sri: Sebastian Riedel <sri@cpan.org>

CONTRIBUTORS

abw: Andy Wardley

acme: Leon Brocard <leon@astray.com>

abraxxa: Alexander Hartmaier <abraxxa@cpan.org>

Andrew Bramble

Andrew Ford <A.Ford@ford-mason.co.uk>

Andrew Ruthven

andyg: Andy Grundman <andy@hybridized.org>

audreyt: Audrey Tang

bricas: Brian Cassidy <bricas@cpan.org>

Caelum: Rafael Kitover <rkitover@io.com>

chansen: Christian Hansen

chicks: Christopher Hicks

Chisel Wright "pause@herlpacker.co.uk"

Danijel Milicevic "me@danijel.de"

David Kamholz <dkamholz@cpan.org>

David Naughton, "naughton@umn.edu"

David E. Wheeler

dhoss: Devin Austin <dhoss@cpan.org>

dkubb: Dan Kubb <dan.kubb-cpan@onautopilot.com>

Drew Taylor

dwc: Daniel Westermann-Clark <danieltwc@cpan.org>

esskar: Sascha Kiefer

fireartist: Carl Franks <cfranks@cpan.org>

frew: Arthur Axel ``fREW'' Schmidt <frioux@gmail.com>

gabb: Danijel Milicevic

Gary Ashton Jones

Gavin Henry "ghenry@perl.me.uk"

Geoff Richards

groditi: Guillermo Roditi <groditi@gmail.com>

hobbs: Andrew Rodland <andrew@cleverdomain.org>

ilmari: Dagfinn Ilmari MannsA~Xker <ilmari@ilmari.org>

jcamacho: Juan Camacho

jester: Jesse Sheidlower "jester@panix.com"

jhannah: Jay Hannah <jay@jays.net>

Jody Belka

Johan Lindstrom

jon: Jon Schutz <jjschutz@cpan.org>

Jonathan Rockway "<jrockway@cpan.org>"

Kieren Diment "kd@totaldatasolution.com"

konobi: Scott McWhirter <konobi@cpan.org>

marcus: Marcus Ramberg <mramberg@cpan.org>

miyagawa: Tatsuhiko Miyagawa <miyagawa@bulknews.net>

mst: Matt S. Trout <mst@shadowcatsystems.co.uk>

mugwump: Sam Vilain

naughton: David Naughton

ningu: David Kamholz <dkamholz@cpan.org>

nothingmuch: Yuval Kogman <nothingmuch@woobling.org>

numa: Dan Sully <daniel@cpan.org>

obra: Jesse Vincent

Octavian Rasnita

omega: Andreas Marienborg

Oleg Kostyuk <cub.uanic@gmail.com>

phaylon: Robert Sedlacek <phaylon@dunkelheit.at>

rafl: Florian Ragwitz <rafl@debian.org>

random: Roland Lammel <lammel@cpan.org>

Robert Sedlacek "<rs@474.at>"

SpiceMan: Marcel Montes

sky: Arthur Bergman

szbalint: Balint Szilakszi <szbalint@cpan.org>

t0m: Tomas Doran <bobtfish@bobtfish.net>

Ulf Edvinsson

Viljo Marrandi "vilts@yahoo.com"

Will Hawes "info@whawes.co.uk"

willert: Sebastian Willert <willert@cpan.org>

wreis: Wallace Reis <wallace@reis.org.br>

Yuval Kogman, "nothingmuch@woobling.org"

rainboxx: Matthias Dietrich, "perl@rainboxx.de"

LICENSE

This library is free software. You can redistribute it and/or modify it under the same terms as Perl itself.