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
+though, and you might want to look at CatInABox at
L<http://use.perl.org/~jk2addict/journal/28071>, especially if you are
on a system that lacks a compiler.
Catalyst includes a helper script, C<catalyst.pl>, that will set up a
skeleton application for you:
- $ catalyst MyApp
+ $ catalyst.pl tutorial
- created "MyApp"
- created "MyApp/script"
+ created "tutorial"
+ created "tutorial/script"
... output snipped
- created "MyApp/script/myapp_create.pl"
+ created "tutorial/script/tutorial_create.pl"
This creates the directory structure, populated with skeleton
files.
You can test out your new application by running the server script that
Catalyst provides:
- $ cd MyApp
- $ script/myapp_server.pl
+ $ cd tutorial
+ $ script/tutorial_server.pl
- [...] [catalyst] [debug] Debug messages enabled
- [...] [catalyst] [debug] Loaded plugins:
+ [debug] Debug messages enabled
+ [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:
+ [debug] Loaded dispatcher "Catalyst::Dispatcher"
+ [debug] Loaded engine "Catalyst::Engine::HTTP"
+ [debug] Found home "/home/users/me/tutorial"
+ [debug] Loaded Private actions:
.--------------------------------------+---------------------------------------.
| Private | Class |
+--------------------------------------+---------------------------------------+
- | /default | MyApp |
+ | /default | tutorial |
'--------------------------------------+---------------------------------------'
- [...] [catalyst] [info] MyApp powered by Catalyst 5.5
+ [...] [catalyst] [info] tutorial powered by Catalyst 5.67
You can connect to your server at http://localhost:3000
(Note that each line logged by Catalyst begins with a timestamp, which has
Content-Length: 5525
Content-Type: text/html; charset=utf-8
Status: 200
- X-Catalyst: 5.5
+ X-Catalyst: 5.67
[...]
Connection closed by foreign host.
$
-You can see the full welcome message by visting
+You can see the full welcome message by visiting
http://localhost:3000/ with your browser.
More trace messages will appear in the original terminal window:
- [...] [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)
+ [debug] *** Request 1 (0.063/s) [2148]
+ [debug] Arguments are ""
+ [debug] "GET" request for "/" from localhost
+ [info] Request took 0.046883s (21.330/s)
.------------------------------------------------------------------+-----------.
| Action | Time |
+------------------------------------------------------------------+-----------+
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/myapp_test.pl>.
+helper script, C<script/tutorial_test.pl>.
=head2 Getting started
-So you picked Catalyst. Good choice. I assume you've installed it as
+So you picked Catalyst. Good choice. We assume you have installed it as
well. For this tutorial you will also need the following modules:
L<Catalyst::Plugin::Session>
...
-To get started all you need to do is type:
+If you have not already done this following the example above, then to get
+started all you need to do is type:
-B<catalyst.pl tutorial>
+ catalyst.pl tutorial
+
+=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.
+
+=cut
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.
-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.
+If you now run the built-in mini-server with:
+
+ 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
+http://localhost:3000/ to see the built-in Catalyst welcome screen.
-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
+The other important thing B<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
+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";
+"tutorial::something".
The root controller is used to load plugins, to configure the
application and its plugins, and for generic private actions. We will
the built-in mini-server as described in L<Getting started>.
If you want to output any debugging information to the console, then
-call C<< $context->log->debug() >>, passing it a string to output. For
-data structures, use Data::Dumper and call C<<
-$context->log->debug(Dumper($structure)) >>
+call C<< $c->log->debug() >>, passing it a string to output. For data
+structures, C<use> L<Data::Dumper> and call C<<
+$c->log->debug(Dumper($structure)) >>
=head2 Model/View/Controller
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
+"MVC". See L<http://en.wikipedia.org/wiki/Model-view-controller>).
+
+The point of the MVC pattern is to separate 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.
+all the benefits of modularity. The main benefits are interchangeability
+of parts and reusability of 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.
+Thus you could replace your flat-file data storage with a relational
+database, or your MySQL database with an Oracle database, and not have
+to change any of your Controller 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.
=head3 Model
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.
+need multiple data sources, each having its 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.
+the View 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. One easy way to do this with Catalyst is to use a templating
+system such as L<Template Toolkit|Template>. If outputting HTML is all
+you are going to do, then you will probably only need one View.
=head3 Controller
-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
+A controller is responsible for responding 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.
+mentioned briefly, and can be read about in detail elsewhere in the
+manual.
=head2 Controlling
-Now lets write our first bit of application code. First, we would like
+Now let's 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>
+ 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
+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 = $context->req->param('name');
+ my $name = $c->req->param('name');
$c->log->debug("Got name: $name\n");
if ($c->req->method eq 'POST') {
$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.
+Whew! So, what does all this do? Let's 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 $c. The context is the magical
-object containing any information you need from catalyst, or want to send to
-it. You will see it used frequently in Catalyst applications, and a list
-of all its methods is available in the L<Catalyst> POD.
+is commonly called the "context", held in C<$context>, or abbreviated to
+C<$c>. From now on, whenever we are talking about the context object,
+it will be represented as C<$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 request
-object to retrieve one of the query parameters, just like in L<CGI>.
+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.
+Next, if we have a post request, we check if the name field contains
+anything (or is "true"). If it isn't, we assign an error message to a
+"message" field in the stash. The stash is a special hash of the context
+object, which allows us to pass data on to other methods we call later,
+typically in the View.
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.
+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:
+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? In
+this tutorial, we'll use Template Toolkit for our viewing. To create our
+TT-based view, just run the following command:
-B<script/tutorial_create.pl view TToolkit TT>
+ 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
+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.
+This is a special 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 in any request
+cycle. If there is one in a controller, it will be preferred 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, $context) = @_;
- $context->forward('tutorial::View::TToolkit') unless $c->res->body();
- }
+ sub end : Private {
+ my ($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.
+(This is the second and last attribute type we'll be using in this
+tutorial.) 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.
+view. The forward method, when just passed a class name, calls
+C<process> on that class. The standard TT view's C<process> method
+renders the template named in the template 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
+NB: This is such a common way to end your 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.
+Template Toolkit also has access to the entire context object via the
+special variable "c". For example, using C<[% 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.
- <p>[%message%]</p>
- <form action="[%c.req.uri%]" method="post">
+ <html><head><title> [% c.config.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:
+In the example above, we use C<[% 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')%]
+ [% 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..
+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.
+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
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
+Now we can run our application again by killing (B<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).
+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 restricting access to pages (which we could do with
+just Apache's 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.
+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:
+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 user's credentials (one of the
+L<Catalyst::Plugin::Authentication::Credential> modules). 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:
+To configure, add some users to the config call. For example:
authentication => { 'users' =>
{ 'fred' =>
}
}
-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>.
+Generally, setting up configuration data for plugins is done based on
+the type of plugin. Check the documentation of the plugin for exact
+details; in this example we should look 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)
+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'd
+need to save 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
+To allow creation of new users we'll add a C<create> action to our Users
controller.
- sub create : Local
- {
+ sub create : Local {
my ($self, $c) = @_;
- my ($username, $passwd1, $passwd2) = map { $context->req->param($_)}
+ my ($username, $passwd1, $passwd2) = map { $c->req->param($_)}
('username', 'password', 'passwordverify');
- if($username && $passwd1 && $passwd2)
- {
- if($c->config->{authentication}{users}{$username})
- {
- $c->stash->{message} = 'Sorry that user already exists';
+ if($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)
- {
- $c->config->({%{$context->config},
- ($username => { password => $passwd1}});
+ elsif($passwd1 eq $passwd2) {
+ $c->config->{authentication}->{users}->{$username} =
+ {password => $passwd1};
$c->stash->{message} = 'User created!';
}
- else
- {
+ else {
$c->stash->{username} = $username;
- $c->stash->{message} = 'Passwords don't match!';
+ $c->stash->{message} = 'Passwords do not match!';
}
}
$c->stash->{template} = 'usercreate.tt';
}
-All this is doing is checking that all the appropriate fields are filled,
-the password fields contain the same data, and then adding the user to the
-config hash. All the checks produce a message which can be displayed to
-the user via the View.
+All this is doing is checking that all the appropriate fields are
+filled, and that the password fields contain the same data, and then
+adding the user to the config hash. All the checks produce a message
+which can be displayed to the user via the View.
+
+The usercreate.tt template looks like this:
+
+ <html><head><title>[% c.config.name %]</title></head><body>
+ <h1>Create a new user</h1>
+ <h2>Current users are:</h2>
+ <p>
+ [% FOREACH key = c.config.authentication.users.keys %]
+ [% key %]<br/>
+ [% END %]
+ </p>
+ <p> [% message %] </p>
+ <form action="/users/create" method="post">
+ <p>User Name: <input type="text" name="username"/></p>
+ <p>Password: <input type="password" name="password"/></p>
+ <p>Confirm Password: <input type="password" name="passwordverify"/></p>
+ <p><input type="submit" name="submit" value="submit"></p>
+ </form>
+ </body></html>
+
+In order for our users to be able to login, we need a C<login> action
+which we put in the Users controller:
+
+ sub login : Local {
+ my ($self, $c) = @_;
+ $c->stash->{template} = 'userlogin.tt';
+ if(!$c->login()) {
+ $c->stash->{message} = 'Please login.';
+ }
+ else {
+ $c->stash->{message} = "Welcome " . $c->user->id;
+ }
+ }
-So our that users can login, we need a login page:
- sub login : Local
- {
- my ($self, $context) = @_;
- $c->stash->{template} = 'userlogin.tt';
- if(!$c->login()) {
- $c->stash->{message} = 'Login failed.';
- }
- }
+And the userlogin.tt template:
-Verrrry simple. Since Credential::Password's "login" call extracts the
-username/password data from the query itself (assuming we use a standard
+ <html><head><title>[% c.config.name %]</title></head><body>
+ <p> [% 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>
+
+
+Very 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;
+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
Magic!
-=head2 Authorising
+=head2 Exercise
+
+As an exercise for the reader, do the following:
+
+Change C<users/greet> and C<greet.tt> so that the welcome message greets
+the user by name.
-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
+Enforce user logging in by adding an C<auto> action in tutorial.pm (see
+the L<Catalyst> documentation to find out about the C<auto> action).
+
+=head2 Authorizing
+
+Authentication is about verifying users, and authorization is about
+allowing them to do things. Catalyst currently has two Authorization
+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.)
+also supports Roles as done by the roles module.) This example uses
+L<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
authentication => { 'users' =>
{ 'fred' =>
{ 'password' => 'fred1234',
- 'roles' => ['admin']
+ '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<< $context->check_user_roles() >> in each action. So we can
-make a restricted I<localhost:3000/users/groups> page like this:
+to call C<< $c->check_user_roles() >> in each action. So we can
+make a restricted I<http://localhost:3000/users/groups> page like this:
- sub groups : Local
- {
- my ($self, $context) = @_;
+ sub groups : Local {
+ my ($self, $c) = @_;
if($c->check_user_roles('admin')) {
# Now we can do things only an admin will see
- if(my $params = $c->req->params) {
+ 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});
}
- $context->stash->{message} = 'Updated user roles!';
+ $c->stash->{message} = 'Updated user roles!';
}
else {
- $context->stash->{users} = $context->config->{authentication};
+ $c->stash->{users} = $c->config->{authentication};
}
- $context->stash->{template} = 'usersgroups.tt';
+ $c->stash->{template} = 'usersgroups.tt';
}
else {
- $context->stash->{message} = 'Admins Only!';
- $context->stash->{template} = 'error.tt';
+ $c->stash->{message} = 'Admins Only!';
+ $c->stash->{template} = 'error.tt';
}
}
-What we are doing here is checking whether the logged in user (used by
-default in the check_user_roles method), is a member of the admin group.
-If it is, then we display the usergroups template, and update the users
-hash as required. Otherwise, we just show the user an error page.
+What we are doing here is checking whether the logged-in user (used by
+default in the C<check_user_roles> method) is a member of the admin
+group. If it is, then we display the usergroups template, and update
+the users hash as required. Otherwise, we just show the user an error
+page.
+
+For this simple example, the usersgroups.tt and error.tt templates could
+both look like this:
+
+ <html><head><title>[% c.config.name %]</title></head><body>
+ <p>[% message %]</p>
+ <p>[% c.stash.users %]</p>
+ </body></html>
And that's all there is to it.
+=for authors
+So it's not clear what the groups action is doing - and with the
+current template, nothing happens. Running through the sample code,
+it's clear what's happening (which is very little), but the purpose,
+and how to display data is not clear.
+
+=cut
+
+So that you can test this out properly without having to go to the
+trouble of deleting browser cookies manually, we will add a logout
+action in the Users controller:
+
+ sub logout : Local {
+ my ($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.
+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, but models can also
+use other data sources, for example another website, or an RSS feed.
-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.
+If you have or want a database, there are still choices to be
+made. There are several modules for accessing databases using an
+object-oriented wrapper. The best known are probably L<DBIx::Class> and
+L<Class::DBI>. 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>:
+For a simple example, we will allow our users to store their favorite
+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>
+ 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:
+Now we need a form for our users to enter/edit their personal greetings
+in, so we'll make a I<http://localhost:3000/users/editgreeting> page:
sub editgreeting : Local {
my ($self, $c) = @_;
$c->stash->{message} = "You're not logged in!";
}
else {
- my $grtable = $context->model('UserData::Greetings');
- my $record = $grtable->find_or_create(user => $context->user->id);
- $record->greeting($context->req->params->{greeting};
+ 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';
}
-Using C<< $context->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.
+Using C<< $c->user_exists >> from the Authentication plugin, this checks
+whether the user is logged in already. If they are, and they have
+entered a new greeting, we use DBIx::Class' C<find_or_create> method 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.
=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
+"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:
-
- use Catalyst qw/-Engine=Apache/;
-
-or
-
- use Catalyst qw/-Engine=FastCGI/;
+servers to run it on. The current popular ones are Apache and FastCGI.
=head3 Apache
-Apache also needs configuring, we need to tell it to load your
+Apache 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:
<Location />
- SetHandler perl-script
- PerlResponseHandler MyApp
+ SetHandler perl-script
+ PerlResponseHandler tutorial
</Location>
-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:
+You will need to install the perl modules of your application into one
+of perl's 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:
- PerlSwitches -I/path/to/MyApp/
+ PerlSwitches -I/path/to/tutorial/
-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.
+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 details of the slightly different ways to do it.
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.
+PerlModule directive. This means that there will be less of a delay when
+your application is accessed.
- PerlModule MyApp
+ PerlModule tutorial
=head3 FastCGI
-These instructions apply to the use of C<mod_fastcgi> under Apache (either 1 or 2 series).
+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.
+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<tutorial_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).
+In all of these examples, we assume that the C<DocumentRoot> is
+C</var>, that our app is called C<tutorial> 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).
=head4 static application
-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:
+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/
+ FastCgiServer /usr/apps/tutorial/script/tutorial_fastcgi.pl
+ Alias / /usr/apps/tutorial/script/tutorial_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
+ Alias /theapp /usr/apps/tutorial/script/tutorial_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.
+Note the detail of the trailing C</ >: this is a general rule of 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.
=head4 dynamic application
-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:
+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:
FastCgiConfig -autoUpdate
- <Directory /usr/apps/MyApp/script>
+ <Directory /usr/apps/tutorial/script>
Options +ExecCGI
<Files *_fastcgi.pl>
- SetHandles fastcgi-script
+ SetHandler fastcgi-script
</Files>
</Directory>
- Alias / /usr/apps/MyApp/script/myapp_fastcgi.pl/
+ Alias / /usr/apps/tutorial/script/tutorial_fastcgi.pl/
Again, if you want your app under C</theapp>, change the C<Alias> line to:
- Alias /theapp /usr/apps/MyApp/script/myapp_fastcgi.pl
+ Alias /theapp /usr/apps/tutorial/script/tutorial_fastcgi.pl
=head4 external server
-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.
+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.
-If you want to use a UNIX socket (on the filesystem), put this in Apache's configuration:
+If you want to use a UNIX socket (on the filesystem), put this in
+Apache's configuration:
- FastCgiExternalServer /tmp/somewhere -socket /tmp/myapp-socket
+ FastCgiExternalServer /tmp/somewhere -socket /tmp/tutorial-socket
Alias / /tmp/somewhere/
-Note that C</tmp> should I<not> exist: it's just a name to connect the two parts.
+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:
+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
+ $ cd /usr/apps/tutorial
+ $ ./script/tutorial_fastcgi -l /tmp/tutorial-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.
+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:
+Upgrading your application to newer Catalyst versions is quite
+simple. After installing the new Catalyst package, just run:
-B<catalyst.pl -scripts>
+ 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:
+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>
+ diff tutorial/lib/tutorial/View/TT.pm tutorial/lib/tutorial/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.)
+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 AUTHOR
+=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>
+Gavin Henry, C<ghenry@cpan.org>
Please send comments, corrections and suggestions for improvements to
-jrobinson@cpan.org
+jrobinson@cpan.org, ghenry@cpan.org
=head1 TODO
-Add template examples.
+Finish DBIC examples with templates and tested code. Make /users/groups
+do something "useful".
-Many other things..
+Many other things....
=head1 COPYRIGHT
projects / catagits/Catalyst-Runtime.git / blobdiff