X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FCatalyst%2FManual%2FTutorial.pod;h=6c395af8e0250a1abd275449cd56398fe0b6e86f;hb=c82bce98625d13b20045499ddbb13b813a788ff3;hp=dea503ea95f363832b29d399400de289f0290dfb;hpb=b460ad78a952bcaaa8f468d6e578c17002d0645b;p=catagits%2FCatalyst-Runtime.git

diff --git a/lib/Catalyst/Manual/Tutorial.pod b/lib/Catalyst/Manual/Tutorial.pod
index dea503e..6c395af 100644
--- a/lib/Catalyst/Manual/Tutorial.pod
+++ b/lib/Catalyst/Manual/Tutorial.pod
@@ -6,312 +6,822 @@ Catalyst::Manual::Tutorial - Getting started with Catalyst
 
 This document aims to get you up and running with Catalyst.
 
-NOTE: THIS DOCUMENT IS STILL VERY MUCH IN AN EARLY DRAFT STATE.  SEE THE NOTES
-AT THE BOTTOM OF THE DOCUMENT.
-
-
-
 =head2 Installation
 
-The first step is to install Catalyst, and the simplest way to do this is to
-install the Catalyst bundle from CPAN:
+The first step is to install Catalyst, and the simplest way to do this 
+is to install the Catalyst bundle from CPAN:
 
-    $ perl -MCPAN -e 'install Bundle::Catalyst'
+    $ perl -MCPAN -e 'install Task::Catalyst'
 
-This will retrieve Catalyst and a number of useful extensions and install them
-for you.
+This will retrieve Catalyst and a number of useful extensions and 
+install them for you. This process might not be totally painless
+though, and you might want to look at CatInABox 
+L<http://use.perl.org/~jk2addict/journal/28071>, especially if you are
+on a system that lacks a compiler.
 
 
-=head2 Setting up your application
+=head2 The very basics - Setting up the skeleton application.
 
-Catalyst includes a helper script, C<catalyst.pl>, that will set up a skeleton
-application for you:
+Catalyst includes a helper script, C<catalyst.pl>, that will set up a 
+skeleton application for you:
 
-    $ catalyst.pl My::App
-    created "My-App"
-    created "My-App/script"
-    created "My-App/lib"
-    created "My-App/root"
-    created "My-App/t"
-    created "My-App/t/m"
-    created "My-App/t/v"
-    created "My-App/t/c"
-    created "My-App/lib/My/App"
-    created "My-App/lib/My/App/M"
-    created "My-App/lib/My/App/V"
-    created "My-App/lib/My/App/C"
-    created "My-App/lib/My/App.pm"
-    created "My-App/Makefile.PL"
-    created "My-App/README"
-    created "My-App/Changes"
-    created "My-App/t/01app.t"
-    created "My-App/t/02podcoverage.t"
-    created "My-App/script/cgi.pl"
-    created "My-App/script/nph-cgi.pl"
-    created "My-App/script/fcgi.pl"
-    created "My-App/script/server.pl"
-    created "My-App/script/test.pl"
-    created "My-App/script/create.pl"
+    $ catalyst MyApp
 
-This creates the directory structure shown, populated with skeleton files.
+    created "MyApp"
+    created "MyApp/script"
+    ... output snipped
+    created "MyApp/script/myapp_create.pl"
 
+This creates the directory structure, populated with skeleton 
+files.
 
-
-=head2 Testing out the sample application
+=head2 Testing out the skeleton application
 
 You can test out your new application by running the server script that
-catalyst provides:
+Catalyst provides:
+
+    $ cd MyApp
+    $ script/myapp_server.pl 
 
-    $ cd My-App
-    $ script/server.pl 
     [...] [catalyst] [debug] Debug messages enabled
-    [...] [catalyst] [debug] Loaded engine "Catalyst::Engine::CGI"
-    [...] [catalyst] [debug] Initialized components ""
-    [...] [catalyst] [info] My::App powered by Catalyst 4.26
-    [...] [catalyst] [debug] "My::App" defined "!default" as "CODE(0x83fd570)"
+    [...] [catalyst] [debug] Loaded plugins:
+    .------------------------------------------------------------------------------.
+    | Catalyst::Plugin::Static::Simple                                             |
+    '------------------------------------------------------------------------------'
+    [...] [catalyst] [debug] Loaded dispatcher "Catalyst::Dispatcher"
+    [...] [catalyst] [debug] Loaded engine "Catalyst::Engine::HTTP"
+    [...] [catalyst] [debug] Found home "/home/users/me/MyApp"
+    [...] [catalyst] [debug] Loaded Private actions:
+    .--------------------------------------+---------------------------------------.
+    | Private                              | Class                                 |
+    +--------------------------------------+---------------------------------------+
+    | /default                             | MyApp                                 |
+    '--------------------------------------+---------------------------------------'
+
+    [...] [catalyst] [info] MyApp powered by Catalyst 5.5
     You can connect to your server at http://localhost:3000
 
-(Note that each line logged by Catalyst includes a timestamp, which has been
-replaced here with "C<...>" so that the text fits onto the lines.)
+(Note that each line logged by Catalyst begins with a timestamp, which has
+been replaced here with "C<...>" so that the text fits onto the lines.)
 
-The server is now waiting for you to make requests of it.  Try using telnet to
-manually make a simple GET request of the server (when telnet responds with
-"Escape character is '^]'.", type "GET / HTTP/1.0" and hit return twice):
+The server is now waiting for you to make requests of it.  Try using 
+telnet to manually make a simple GET request of the server (when 
+telnet responds with "Escape character is '^]'.", type "GET / HTTP/1.0"
+and hit return twice):
 
     $ telnet localhost 3000
     Trying 127.0.0.1...
     Connected to localhost.
     Escape character is '^]'.
     GET / HTTP/1.0
-    
-    HTTP/1.0 200
-    Server: Catalyst/4.26
+
+    HTTP/1.0 200 OK
+    Date: Mon, 07 Nov 2005 14:57:39 GMT
+    Content-Length: 5525
+    Content-Type: text/html; charset=utf-8
     Status: 200
-    Date: Sun, 20 Mar 2005 12:31:55 GMT
-    X-catalyst: 4.26
-    Content-length: 40
-    Content-Type: text/html; charset=ISO-8859-1
+    X-Catalyst: 5.5
 
-    Congratulations, My::App is on Catalyst!
+    [...]
     Connection closed by foreign host.
     $
 
+You can see the full welcome message by visting
+http://localhost:3000/ with your browser.
+
 More trace messages will appear in the original terminal window:
 
-    [...] [catalyst] [debug] ********************************
-    [...] [catalyst] [debug] * Request 1 (0.027/s) [9818]
-    [...] [catalyst] [debug] ********************************
-    [...] [catalyst] [debug] "GET" request for ""
-    [...] [catalyst] [debug] Using default action
-    [...] [catalyst] [info] Processing "!default" took 0.000033s
-    [...] [catalyst] [info] Request took 0.051399s (19.456/s)
+    [...] [catalyst] [debug] **********************************
+    [...] [catalyst] [debug] * Request 1 (0.063/s) [2148]
+    [...] [catalyst] [debug] **********************************
+    [...] [catalyst] [debug] Arguments are ""
+    [...] [catalyst] [debug] "GET" request for "" from localhost
+    [...] [catalyst] [info] Request took 0.046883s (21.330/s)
+    .------------------------------------------------------------------+-----------.
+    | Action                                                           | Time      |
+    +------------------------------------------------------------------+-----------+
+    | /default                                                         | 0.000000s |
+    '------------------------------------------------------------------+-----------'
 
 The server will continue running until you interrupt it.
 
 The application can also be tested from the command line using the generated
-helper script, C<script/test.pl>.
+helper script, C<script/myapp_test.pl>.
 
+=head2 Getting started
 
-=head2 Getting your application invoked
+So you picked Catalyst. Good choice. I assume you've installed it as
+well. For this tutorial you will also need the following modules:
 
-Catalyst applications are usually run from mod_perl, but can also be run as
-CGI or FastCGI scripts.  Running under mod_perl gives better performance, but
-for development purposes you may want to run your application as a CGI script,
-especially as changes to your application code take effect under CGI without
-having to restart the web server.
+L<Catalyst::Plugin::Session>
 
-To run from mod_perl you need to add something like this to your Apache
-configuration file:
+L<Catalyst::Plugin::Session::Store::File>
 
-    <Location /my-app>
-        SetHandler  perl-script
-        PerlHandler My::App
-    </Location>
+L<Catalyst::Plugin::Session::State::Cookie>
 
-To run as a CGI script you need a wrapper script like:
+L<Catalyst::Plugin::Authentication>
 
-    #!/usr/bin/perl -w
+L<Catalyst::Plugin::Authentication::Store::Minimal>
 
-    use strict;
-    use lib '/path/to/My/App/lib';
-    use My::App;
+L<Catalyst::Plugin::Authentication::::Minimal>
 
-    My::App->run;
+L<Catalyst::Plugin::Authentication::Credential::Password>
 
-Catalyst outputs a complete HTTP response, which is not what is expected of a
-CGI script.  You need to configure the script as a so-called "Non-parsed
-Headers" script for it to function properly.  To do this in Apache just name
-the script starting with C<nph->.
+L<Catalyst::Plugin::Authorization::Roles>
 
-CHECK: is this statement still valid for Cat5?
+L<DBD::SQLite>
 
+...
 
-=head2 Examining the generated code
+To get started all you need to do is type:
 
-The generated application code is quite simple and looks something like this:
+B<catalyst.pl tutorial>
 
-    package My::App;
+=for commentary
+Poor choice of application name - searching for "tutorial" in the docs
+also results in discussion of the tutorial process, which is probably
+not what the reader wants.
 
-    use strict;
-    use Catalyst qw/-Debug/;
+=cut
 
-    our $VERSION = '0.01';
+This should create a directory called F<tutorial> and fill it with the
+default (standard) Catalyst installation. Change to this directory
+because we will be running all further commands from inside the
+F<tutorial> directory.
 
-    My::App->config(
-	name => 'My::App',
-	root => '/home/andrew/My-App/root',
-    );
+If you now run the built-in mini-server with
+B<script/tutorial_server.pl>, it will show some standard debug messages
+in the console screen (more about those in a minute), and then inform
+you that you can now connect to the test server on port 3000. Point your
+browser at localhost:3000 to see the built-in catalyst welcome screen.
 
-    My::App->action(
-	'!default' => sub {
-	    my ( $self, $c ) = @_;
-	    $c->res->output('Congratulations, My::App is on Catalyst!');
-	},
-    );
+The other important thing catalyst.pl did was create your root
+controller. This file is a standard perl module like all the other
+controllers that you might add to your application.  It lives in the
+F<lib/> directory, and will have the same name as you supplied to the
+command above, in our case it is F<tutorial.pm>. Alongside this file is
+a directory of the same name, which is the top level namespace for the
+entire application. Thus every other module we create will be
+"tutorial::something";
 
-    1;
+The root controller is used to load plugins, to configure the
+application and its plugins, and for generic private actions.  We will
+explain more about those later.
 
+=head2 Debugging
 
-When the C<Catalyst> module is imported by the application code, Catalyst
-performs the first stage of its initialization.  This includes loading the
-appropriate Engine module for the environment in which the application is
-running, loading any plugins and ensuring that the calling module (the
-application module) inherits from C<Catalyst> (which makes the Catalyst
-methods C<config> and C<action> available to the application module).
+The simplest way to debug your Catalyst application is to run it using
+the built-in mini-server as described in L<Getting started>. 
 
-The call to C<config> sets up configuration data for the application.  The
-C<name> and C<root> items are the minimum required, and specify the name of
-the application and the path to the root directory where documents, images and
-templates can be found.
+If you want to output any debugging information to the console, then
+call C<< $c->log->debug() >>, passing it a string to output. For
+data structures, use Data::Dumper and call C<<
+$c->log->debug(Dumper($structure)) >>
 
-Catalyst associates I<actions> with URLs and on receiving a request dispatches
-to the action that matches to request URL.  The call to C<action> in the code
-above registers a default action.  With just this action registered the
-application will respond to all requests with the same message
-"Congratulations, My::App is on Catalyst!".
+=head2 Model/View/Controller
 
-TODO: mention private actions and attributes
+The recommended method for code organization in a Catalyst application
+is known as the "Model View Controller" design pattern (also referred to
+"MVC"). The point of the MVC pattern is to divorce the dependencies of
+parts of the application from each other, and give them standard
+interfaces. Following this theory of organization should give your code
+all the benefits of modularity.  The main benefits are interchangability
+of parts and reusable code.
 
+Thus you could replace your file data storage with a database or your
+oracle database with a mysql database and not have to change any of your
+controlling or view logic. Or you could later decide to output
+information from your application as RSS instead of HTML just by adding
+a new view module.
 
-The first call to the C<action> method triggers the second stage of Catalyst's
-initialization process.  In this phase Catalyst searches for any component
-modules, locating and registering any actions it finds in those modules.
-Component modules have names prefixed with the application module name,
-followed by C<Model>, C<View> or C<Controller> (or the alternative short
-forms: C<M>, C<V> or C<C>) followed by the component name, for example:
+=head3 Model
 
-    My::App::Controller::ShoppingCart
+Models deal with the storage of data. For a complex website, you may
+need multiple varied data sources, each will have it's own model class
+that provides an abstracted interface to it. In this tutorial we are
+going to be using a simple database.
 
+=head3 View
 
+Views are used to display information to the user. In a web framework,
+it is generally used to output HTML to the browser. As mentioned
+previously, views can also be used to output RSS or any other kind of
+data format.  One easy way to do this with Catalyst is to use a
+templating system such as Template Toolkit. If outputting HTML is all
+you are going to do, then you will probably only need one view.
 
+=head3 Controller
 
-=head2 Extending the generated code
+A controller deals with reacting to user choices, and thus controls what
+the application does. Since this is a web framework, Catalyst
+controllers are frequently used to react directly to URLs requested by
+the user. This tutorial will describe the simplest way of using
+controllers, where each path or part of a path is assigned its own
+action (or subroutine). More complex controlling mechanisms will be
+mentioned briefly, and can be read about in detail in the manual.
 
-NOTE: this section is outdated by Cat5.
 
-You can start extending the application by adding new actions:
+=head2 Controlling
 
-    My::App->action(
-        'test1' => sub {
-	    my ( $self, $c ) = @_;
-	    $c->res->output('In a new test action #1');
-	},
-        'test1' => sub {
-	    my ( $self, $c ) = @_;
-	    $c->res->output('In a new test action #1');
-	},
-	'!default' => sub {
-	    my ( $self, $c ) = @_;
-	    $c->res->output('Congratulations, My::App is on Catalyst!');
-	},
-    );
+Now lets write our first bit of application code. First, we would like
+our application to greet our users. We'll assume for now that our users
+will be sent to the I<users/greet> URL. To create a controller that
+serves the I<users> namespace, we run the following command in our
+F<tutorial> directory:
 
+B<script/tutorial_create.pl controller Users>
+
+This will create a Users.pm in F<lib/tutorial/Controller>. Open this
+file in an editor and take a look. You will notice there is some
+commented out code which we will ignore for now. To make something
+happen when our URL is visited, we will write a "greet" action which
+looks like this:
+
+  sub greet : Local {
+    my ($self, $c) = @_;
+
+    my $name = $c->req->param('name');
+    $c->log->debug("Got name: $name\n");
+
+    if ($c->req->method eq 'POST') {
+       if(!$name) {
+            $c->stash->{message} = 'Please fill in a name!';
+        }
+        else {
+            $c->stash->{message} = "Hello $name!";     
+        }
+    }
+    $c->stash->{template} = 'greet.tt';
+  }
+
+Whew! So, what does all this do? Lets take it one step at a time.
+The subroutine declaration gives the action a name.  To the right of the
+name there is an attribute type that looks like this:  " : Local".  That
+defines which URIs will translate to this action.  "Local", matches
+exactly one URI: /users/greet. The URI matched by "Local" is composed
+from the namespace minus the tutorial::controller portion, that is
+common to all controllers, and the action name itself.  Because it is a
+URI, we use forward slashes instead of double colons.  So, in summary,
+when a user requests http://localhost:3000/users/greet" the "greet"
+action defined above in the Users controller will be executed.
+
+The second line retrieves the parameters Catalyst gives us when it calls
+our method. The first is the instance of our Users class, and the second
+is commonly called the context, and named $c.  From now on, whenever we 
+are talking about the context object, it will be represented as $c in the code.
+
+The context is the magical object containing any information you need from catalyst, 
+or want to send to it, and is passed from action to action. You will see it used 
+frequently in Catalyst applications, and a list of all its methods is available in 
+the L<Catalyst> POD.
+
+On the third line we use the ->param method of the context's request object
+to retrieve one of the query parameters, just like in L<CGI>.
+
+On the fourth, we make a debug output of this object on the server console,
+or the error log if running under CGI or mod_perl.
+
+Next, if we have a post request, we check if the name field contains anything 
+(or is "true"), if it isnt, we assign an error message to a "message" field in 
+the stash. The stash is yet another method of the context object, it allows us
+to pass data on to other methods we call later, most usefully the View modules.
+
+If the username did contain a value, then we just set our message to
+greet the user by name.
+
+Finally, we set the special "template" variable in the stash to the name
+of the template we want our view to use to display this page.
+
+=head2 Viewing
+
+Ok, so reacting and checking the users data is all fine, but how do we
+actually display the page/form in the first place, and our results? As
+previously mentioned, we'll use Template Toolkit for our viewing. To
+create out TT based view, just run the following command:
+
+B<script/tutorial_create.pl view TToolkit TT>
+
+Notice that this time we not only gave it the type of module we wanted
+to create (a view), and a name, but also a third argument, "TT". This is
+a Catalyst helper module, which will make a standard template toolkit
+module for you. And that's all you need to do there.
+
+To use the view, the easiest way is to set up a standard "end" action.
+This a private action which will not be matched to a path like our
+"greet" action, but instead will be called after all other processing is
+done. Only one end action will be called, if there is one in a
+controller, it will be prefered over one in the application module, and
+so on.
+
+Since we're writing a simple application, just add an end action like
+this to F<tutorial.pm>:
+
+ sub end : Private {
+   my ($self, $c) = @_;
+   $c->forward('tutorial::View::TToolkit') unless $c->res->body();
+ }
+
+The first line declares the end sub, and marks it as a Private action.
+(The second and last attribute type we'll be using). The second line
+collects our standard parameters as shown in the controller's greet action.
+
+The third line directs Catalyst to pass processing on to our TToolkit
+view. The forward method, when just passed a class name, calls process
+on that classs. The standard TT view's process method renders the
+template named in the templare variable in the stash, using all the
+other variables in the stash as values to fill it in.
+
+NB: This is such a common way to end you processing that there is a
+plugin which does it for you: L<Catalyst::Plugin::DefaultEnd>.
+
+Template Toolkit also has access to the entire context object via "c",
+for example, using [% c.config.name %] in our template will output
+"tutorial", our project name.
+
+All that remains is to create a simple template called "greet.tt",
+containing a form with a text field called "name" like below.
+
+    <html><head><title> [% c.name %]</head><body>
+    <p>[%message%]</p>
+    <form action="[%c.req.uri%]" method="post">
+    <input type="text" name="name"/>
+    <input type="submit" value="Submit" name="submit"/>
+    </form>
+    </body></html>
+
+In the example above, we use [%c.req.uri%], since we're posting to ourself.
+if we post to another action, we commonly use the uri_for method, like this:
+
+ [% c.uri_for('/users/greet')%]
+
+Place this file in the F<root> directory, . By default, templates are 
+searched for here, but we can change that, which brings us to...
+
+=head2 Configuring
+
+As previously mentioned, the configuration of modules, plugins and so on
+is done in the main application file. This is especially true for bits
+which need to be done before an instance of them is created, for example
+Template Toolkit.
+
+The TT View looks for its templates in the F<root> directory by default.
+Since this is also the directory that static files go in, we'd rather
+have a separate F<templates> directory. To do this, change the config
+call in F<tutorial.pm> like this:
+
+ __PACKAGE__->config( name => 'tutorial',
+                      'View::TToolkit' => {
+                          'INCLUDE_PATH' => __PACKAGE__->path_to('templates')
+     }
+  );
+
+And move the F<greet.tt> file from F<root> to the F<templates> directory
+(after creating it).
+
+Now we can run our application again by killing (ctrl-c) and restarting
+B<script/tutorial_server.pl>. Try connecting to
+I<localhost:3000/users/greet> with a browser and see what happens. What
+happens if you try to visit I<localhost:3000/users> ? 
+
+=head2 Users and Authenticating
+
+One of the many reasons to write dynamic websites instead of just using static 
+HTML, is to allow us to produce different content for different users, as well
+ as just restricting access to pages (which we could do with just Apaches 
+htpasswd system).
+
+In this tutorial, we will just be using basic authentication, when writing 
+a real application, you'll want to use a database or other secure store to 
+contain your user data.
+
+To add authentication, all we need to do is add the
+L<Catalyst::Plugin::Authentication> module to our main application file. Then
+we need to pick a storage method (one of the
+L<Catalyst::Plugin::Authentication::Store> modules), and a method of verifying
+the users credentials (one of the
+L<Catalyst::Plugin::Authentication::Credential> modules), so just edit
+F<tutorial.pm> to look like this: 
+
+ use Catalyst qw/-Debug Static::Simple Authentication 
+                Authentication::Store::Minimal 
+                Authentication::Credential::Password/;
+
+To configure, add some users to the config call, for example: 
+
+ authentication => { 'users' =>
+                       { 'fred' =>
+                           { 'password' => 'fred1234',
+                           }
+                       }
+                   }
+
+Generally, setting up configuration data for plugins is done based on the 
+type of plugin. Check the documentation of the plugin for exact details. The 
+details of this one are in L<Catalyst::Plugin::Authentication::Store::Minimal>.
+
+Since our user data is in the config, we can update it at runtime, and thus 
+add users dynamically. (Of course, to keep them permanently we'll need to 
+export our data to disk and read it back into the config on startup)
+
+To allow creation of new users we'll add a create action to our Users 
+controller.
+
+ sub create : Local {
+    my ($self, $c) = @_;
+    my ($username, $passwd1, $passwd2) = map { $c->req->param($_)} 
+       ('username', 'password', 'passwordverify');
+
+    if($username && $passwd1 && $passwd2) {
+       if($c->config->{authentication}{users}{$username}) {
+          $c->stash->{message} = 'Sorry that user already exists';
+          $c->stash->{username} = $username;
+       }
+       elsif($passwd1 eq $passwd2) {
+            $c->config->{authentication}->{users}->{$username} =
+                {password => $passwd1};
+          $c->stash->{message} = 'User created!';
+       }
+       else {
+          $c->stash->{username} = $username;
+          $c->stash->{message} = 'Passwords do not match!';
+       }
+    }
+    $c->stash->{template} = 'usercreate.tt';
+ }
+
+All this is doing is checking that all the appropriate fields are filled, 
+the password fields contain the same data, and then adding the user to the 
+config hash.  All the checks produce a message which can be displayed to 
+the user via the View.
+
+The usercreate.tt template looks like this:
+
+ <html><head><title>[% c.config.name %]</title></head><body>
+ <h1>Create a new user</h1>
+ <p> [% c.stash.message %] </p>
+ <form action="/users/create" method="post">
+ <p>User Name: <input type="text" name="username"/></p>
+ <p>Password: <input type="password" name="password"/></p>
+ <p>Confirm Password: <input type="password" name="passwordverify"/></p>
+ <p><input type="submit" name="submit" value="submit"></p>
+ </form>
+ </body></html>
+
+So our that users can login, we need a login action which we put in the
+Users controller:
+
+ sub login : Local {
+     my ($self, $c) = @_;
+     $c->stash->{template} = 'userlogin.tt';
+     if(!$c->login()) {
+             $c->stash->{message} = 'Please login.';
+     }
+     else {
+         $c->stash->{message} = "Welcome " . $c->user->id;
+     }
+ }
+
+
+And the userlogin.tt template:
+
+ <html><head><title>[% c.config.name %]</title></head><body>
+<p> [% c.stash.message %] </p>
+ <form name='login' action='/users/login' method='post'>
+ <p>Username: <input type='text' name='user' /></p>
+ <p>Password: <input type='password' name='password' /></p>
+ <p><input type="submit" /></form>
+ </body></html>
+
+
+Verrrry simple. Since Credential::Password's "login" call extracts the 
+username/password data from the query itself (assuming we use a standard 
+name for our form fields), we don't have to do anything but call it.
+
+To keep the user logged in, all we need to do is add the Session modules to 
+our collection, and the Auth modules will automatically use them; 
+
+ use Catalyst qw/-Debug Static::Simple Authentication 
+                 Authentication::Store::Minimal 
+                 Authentication::Credential::Password
+                 Session Session::Store::File Session::State::Cookie/;
+
+Magic!
+
+=head2 Exercise
+
+As an exercise for the reader, do the following:
+
+Change users/greet and greet.tt so that the welcome message greets the
+user by name.
+
+Enforce user logging in by adding an auto action in tutorial.pm (see
+the L<Catalyst> documentation to find out about the auto action).
+
+=head2 Authorising
+
+Authentication is about verifying users, Authorisation is about
+allowing them to do things. Catalyst currently has two Authorisation
+modules, Roles and ACL. The Roles module allows you to define groups
+which you can assign your users to, and then allow access to areas of
+your website to the groups. The ACL module lets you do more fine
+grained access/restriction by allowing of denying access however you
+like. (It also supports Roles as done by the roles module.)  This
+example uses Catalyst::Plugin::Authorization::Roles.  To use this add
+"Authorization::Roles" into the "use Catalyst" statement in
+tutorial.pm.
+
+Adding Roles via the Minimal store we are already using is quite simple,
+we just add a roles key to each user, defining the names of the roles
+they belong to.
+
+ authentication => { 'users' =>
+                            { 'fred' => 
+                               { 'password' => 'fred1234',
+                                 'roles'       => ['admin']
+                               }
+                            }
+                         }
+
+We need an interface for our admins to administer the roles, i.e. assign
+the users to groups. To restrict access to certain actions, we just need
+to call C<< $c->check_user_roles() >> in each action. So we can
+make a restricted I<localhost:3000/users/groups> page like this:
+
+ sub groups : Local {
+    my ($self, $c) = @_;
+    if($c->check_user_roles('admin')) {
+       # Now we can do things only an admin will see
+       if(my $params = $c->req->params) {
+          my $users = $c->config->{authentication}{users};
+          foreach my $u (keys %$params) {
+             $users->{$u}{roles} = $params->{$u} if($users->{$u});
+          }
+          $c->stash->{message} = 'Updated user roles!';
+       }
+       else {
+           $c->stash->{users} = $c->config->{authentication};
+       }
+       $c->stash->{template} = 'usersgroups.tt';
+    }
+    else {
+        $c->stash->{message} = 'Admins Only!';
+        $c->stash->{template} = 'error.tt';
+    }
+ }
+
+What we are doing here is checking whether the logged in user (used by
+default in the check_user_roles method), is a member of the admin group.
+If it is, then we display the usergroups template, and update the users
+hash as required. Otherwise, we just show the user an error page.
+
+For this simple example, the usersgroups.tt and error.tt templates could
+both look like this:
+
+ <html><head><title>[% c.config.name %]</title></head><body>
+ <p>[% c.stash.message %]</p>
+ <p>[% c.stash.users %]</p>
+ </body></html>
+
+And that's all there is to it.
+
+=for authors
+So it's not clear what the groups action is doing - and with the
+current template, nothing happens.  Running through the sample code,
+it's clear what's happening, (which is very little), but the purpose,
+and how to display data is not clear.
+
+=cut
+
+So that you can test this out properly without having to go to the
+trouble of deleting browser cookies manually, we will add a logout
+action in the Users controller:
+
+ sub logout : Local {
+    my ($self, $c) = @_;
+    $c->stash->{message} = "You have successfully logged out";
+    $c->logout;
+ }
+
+
+=head2 Data Storage (Modelling)
+
+Whether we want our users to be able to contribute to our website, or just
+create it from changeable data, we need to store the data somewhere. Generally
+this is done using a database, models can also be other data sources, for
+example another website, or RSS feeds. 
+
+If you have or want a database, there are still choices to be made, there are
+several modules about for accessing databases via OO. The best known are
+probably L<Class::DBI> and L<DBIx::Class>. Catalyst supports making models
+using either of these.  
+
+For a simple example, we will allow our users to store their favourite
+greeting in our database. Create a table called "greetings" in a database,
+that contains a "user" field and a "greeting" field. The simplest way to
+create a model of your database is to use these helper modules, for example
+with L<DBIx::Class>: 
+
+B<script/tutorial_create.pl model UserData DBIC dbi:SQLite:/path/to/mydb.db>
+
+This will cause the DBIx::Class Loader to inspect your database, and create a
+module in the Model::UserData namespace for each table in your database. 
+
+Now we need a form for our users to enter/edit their personal greetings in,
+we'll make a I<localhost:3000/users/editgreeting> page: 
+
+ sub editgreeting : Local {
+    my ($self, $c) = @_;
+    if($c->req->params->{greeting}) {
+       if(!$c->user_exists) {
+          $c->stash->{message} = "You're not logged in!";
+       }
+       else {
+          my $grtable = $c->model('UserData::Greetings');
+          my $record = $grtable->find_or_create(user => $c->user->id);
+          $record->greeting($c->req->params->{greeting};
+          $record->update;
+          $c->stash->{message} = 'Greeting updated';
+       }
+    }
+    $c->stash->{template} = 'usersgreeting.tt';
+ }
 
-TODO: explain briefly about plugins, actions and components
+Using C<< $c->user_exists >> from the Authentication plugin, this checks
+whether the user is logged in already. If they are, if they are, and they have
+entered a new greeting, we use DBIx::Class' C<find_or_create> to fetch or
+create a new record in the greetings table for the user. Once we have the
+record, we change the value of the greeting field, and call C<update> to store
+the new value in the database. 
 
-regex actions passed subexpression matches in $c->req->snippets (array ref).
+=head2 Engines (Apache and FastCGI)
 
+Now that we have the basics together, we can try running our application on a
+"real" server instead of just using the test server that catalyst comes
+with. L<Catalyst::Engine> is the module used to implement various types of
+servers to run it on. The currect popular ones are Apache and FastCGI. To
+force the use of a particular engine we can use the -Engine flag to Catalyst: 
 
-=head2 Hooking in to Template Toolkit
+ use Catalyst qw/-Engine=Apache/;
 
-One of the first things you will probably want to add to your application is a
-templating system for generating your output.  Catalyst works well with
-Template Toolkit.  If you are unfamiliar with Template Toolkit then I suggest
-you look at L<http://tt2.org>, install C<Template>, read the documentation and
-play around with it, and have a look at the I<Badger Book> (I<Template
-Toolkit> by Darren Chamberlain, Dave Cross and Andy Wardly, O'Reilly &
-Associates, 2004).
+or
 
-You can create a stub Template Toolkit view component using the create script
-that Catalyst set up as part of the skeleton application:
+ use Catalyst qw/-Engine=FastCGI/;
 
-    $ script/create.pl view TT TT
+=head3 Apache
 
-this generates a view component named C<My::App::View::TT>, which you might
-use by forwarding from your C<end> action:
+Apache also needs to be configured: we need to tell it to load your
+application. You can either use Catalyst for your entire website, or
+subsections. Use the Location directive to choose a path to run your
+application under: 
 
-    # In My::App or My::App::Controller::SomeController
+ <Location />
+   SetHandler                perl-script
+   PerlResponseHandler  MyApp
+ </Location>
 
-    sub end : Private {
-        my($self, $c) = @_;
-        $c->forward('My::App::View::TT');
-    }
+You will need to install the perl modules of your application into one of
+perls library directories, as listed by B<perl -V>, so that Apache can find
+them. Alternatively you can use the C<PerlSwitches> directive to tell Apache
+where to look: 
 
-The generated TT view component simply subclasses the C<Catalyst::View::TT>
-class.  It looks like this (with the POD stripped out):
+ PerlSwitches -I/path/to/MyApp/
 
-    package My::App::V::TT;
+These instructions are for using Apache2 and mod_perl 2.0. If you are using
+mod_perl 1.3 or 1.99, please refer to either L<Catalyst::Engine::Apache::MP13>
+or L<Catalyst::Engine::Apache2::MP19> for slightly different ways to do it. 
 
-    use strict;
-    use base 'Catalyst::View::TT';
+If you wish to ensure that Apache pre-loads your application, use the
+PerlModule directive. This means that there will be less of a delay when your
+application is accessed. 
 
-    1;
+ PerlModule MyApp
 
-C<Catalyst::View::TT> initializes a Template Toolkit object with an options
-hash initialized with built-in default settings followed by the contents of
-the hash C<<%{__PACKAGE__->config()}>>.  You can configure TT more to your
-needs by adding a C<new> method to the generated TT component:
+=head3 FastCGI
 
-    sub new {
-	my $self = shift;
-	$self->config->{PRE_PROCESS} = 'config/main';
-	$self->config->{WRAPPER}     = 'site/wrapper';
-	return $self->SUPER::new(@_);
-    }
+These instructions apply to the use of C<mod_fastcgi> under Apache
+(either 1 or 2 series).
 
+There are 3 ways to attach a program to a URL with C<mod_fastcgi>;
+we'll examine all of them, and explain how to avoid having the
+C<myapp_fastcgi.pl> substring in the user-visible URLs.
 
+In all of these examples, we assume that the C<DocumentRoot> is
+C</var>, that our app is called C<MyApp> and is kept in C</usr>, that
+you want the users to access the app either from the root of the
+server-uri-space, or from C</theapp>. We also assume that the general
+FastCGI settings (C<FastCgiIpcDir>, loading the module) are already
+correct (they don't depend on Catalyst or your application layout).
 
-=head1 AUTHOR
+=head4 static application
 
-Andrew Ford, C<A.Ford@ford-mason.co.uk>
+In this setup, you tell C<mod_fastcgi> that a particular I<file> is to
+be run as a FastCGI handler. Put this somewhere in Apache's
+configuration:
+
+  FastCgiServer /usr/apps/MyApp/script/myapp_fastcgi.pl
+  Alias / /usr/apps/MyApp/script/myapp_fastcgi.pl/
+
+If you want your app under C</theapp>, change the C<Alias> line to:
+
+  Alias /theapp /usr/apps/MyApp/script/myapp_fastcgi.pl
+
+Note the detail of the trailing C</ >: this is a general rule af the
+C<Alias> directive, both sides must end with C</ >, or both must not;
+you can't have one with C</ > and the other without, or strange things
+happen.
 
-As noted above, this document is at an alpha stage.  My plan for this document
-is as follows:
+=head4 dynamic application
 
-=over 4
+In this setup, you tell C<mod_fastcgi> that certain files are to be
+treated as FastCGI handlers, in the same way you have to tell
+C<mod_cgi>. Put this in the configuration:
 
-=item 1
+  FastCgiConfig -autoUpdate
 
-expand this document fairly rapidly to cover topics relevant to
-a newcomer to Catalyst in an order that can be read sequentially
+  <Directory /usr/apps/MyApp/script>
+   Options +ExecCGI
+   <Files *_fastcgi.pl>
+    SetHandles fastcgi-script
+   </Files>
+  </Directory>
 
-=item 2
+  Alias / /usr/apps/MyApp/script/myapp_fastcgi.pl/
 
-incorporate feedback 
+Again, if you want your app under C</theapp>, change the C<Alias> line to:
 
-=item 3
+  Alias /theapp /usr/apps/MyApp/script/myapp_fastcgi.pl
 
-revise the text 
+=head4 external server
 
-=back
+In this setup, the application is started separately from Apache, and
+communicates via a socket with C<mod_fastcgi>. This can be useful if
+you need to have a particular environment for your application (maybe
+different between applications), or you want to run them on different
+machines, or under different users for security reasons.
 
-Placeholders are indicated by the words: TODO or CHECK 
+If you want to use a UNIX socket (on the filesystem), put this in
+Apache's configuration:
+
+  FastCgiExternalServer /tmp/somewhere -socket /tmp/myapp-socket
+  Alias / /tmp/somewhere/
+
+Note that C</tmp> should I<not> exist: it's just a name to connect the
+two parts.
+
+Again, if you want your app under C</theapp>, change the C<Alias> line
+to:
+
+  Alias /theapp /tmp/somewhere
+
+Then start your Catalyst application:
+
+  $ cd /usr/apps/MyApp
+  $ ./script/myapp_fastcgi -l /tmp/myapp-socket
+
+If you want to use a TCP socket, simply change the C</tmp> to a
+C<host:port> pair, both in Apache's configuration and on the command
+line of your application.
+
+=head2 Upgrading
+
+Upgrading your application to newer Catalyst versions is quite simple. After
+installing the new Catalyst package, just run: 
+
+B<catalyst.pl -scripts>
+
+One level above your application directory. This will update the
+scripts directory only, and leave the rest of your app alone, If you
+wish to make use of other parts of Catalyst that have been updated,
+leave off the B<-scripts> argument, this will cause .new files to
+appear, for each module that has either been updated, or is different
+to the original because you have changed it. To find out what these
+changes are, type:
+
+B<diff MyApp/lib/MyApp/View/TT.pm MyApp/lib/MyApp/View/TT.pm.new>
+
+for each of the changed files. (This is a Unix command, Windows users
+will need to find some equivalent). Copy any changes you need into
+your original file, then remove the .new files. (This makes life less
+complicated when the next upgrade comes around.)
+
+=head1 AUTHORS
+
+Jess Robinson, C<jrobinson@cpan.org>
+Andrew Ford, C<A.Ford@ford-mason.co.uk>
+Marcus Ramberg, C<mramberg@cpan.org>
+Kieren Diment, C<kd@totaldatasolution.com>
 
 Please send comments, corrections and suggestions for improvements to
-A.Ford@ford-mason.co.uk
+jrobinson@cpan.org
+
+=head1 TODO
+
+Finish DBIC examples with templates and tested code.  Make
+/users/groups do something "useful"
 
+Many other things..
 
 =head1 COPYRIGHT
 
-This program is free software, you can redistribute it and/or modify it under
-the same terms as Perl itself.
+This program is free software, you can redistribute it and/or modify 
+it under the same terms as Perl itself.