Catalyst::Manual::Tutorial::Authentication - Catalyst Tutorial - Part 4: Authentication
-
=head1 OVERVIEW
This is B<Part 4 of 9> for the Catalyst tutorial.
=item 3
-L<Basic CRUD|Catalyst::Manual::Tutorial_BasicCRUD>
+L<Basic CRUD|Catalyst::Manual::Tutorial::BasicCRUD>
=item 4
=item 9
-L<Appendicies|Catalyst::Manual::Tutorial::Appendicies>
+L<Appendices|Catalyst::Manual::Tutorial::Appendices>
=back
-
=head1 DESCRIPTION
Now that we finally have a simple yet functional application, we can
-focus on providing authentication (with authorization coming in Part 5).
+focus on providing authentication (with authorization coming next in
+Part 5).
This part of the tutorial is divided into two main sections: 1) basic,
cleartext authentication and 2) hash-based authentication.
-B<TIP>: Note that all of the code for this part of the tutorial can be
-pulled from the Catalyst Subversion repository in one step with the
-following command:
-
- svn checkout http://dev.catalyst.perl.org/repos/Catalyst/trunk/examples/Tutorial@###
- IMPORTANT: Does not work yet. Will be completed for final version.
-
-
+You can checkout the source code for this example from the catalyst
+subversion repository as per the instructions in
+L<Catalyst::Manual::Tutorial::Intro>
=head1 BASIC AUTHENTICATION
-This section explores how add authentication logic to a Catalyst application.
+This section explores how to add authentication logic to a Catalyst
+application.
=head2 Add Users and Roles to the Database
-First, we add both user and role information to the database (we add the
-role information here although it will not be used until the
+First, we add both user and role information to the database (we will
+add the role information here although it will not be used until the
authorization section, Part 5). Create a new SQL script file by opening
C<myapp02.sql> in your editor and insert:
$ sqlite3 myapp.db < myapp02.sql
-=head2 Add User and Role Information to Dbic Schema
+=head2 Add User and Role Information to DBIC Schema
This step adds DBIC-based classes for the user-related database tables
-(the role information will not be used until the Part 5):
+(the role information will not be used until Part 5):
Edit C<lib/MyAppDB.pm> and update the contents to match (only the
C<MyAppDB =E<gt> [qw/Book BookAuthor Author User UserRole Role/]> line
=head2 Include Authentication and Session Plugins
-Edit C<lib/MyApp.pm> and update it as follows (everything below C<DefaultEnd> is new):
+Edit C<lib/MyApp.pm> and update it as follows (everything below C<StackTrace> is new):
use Catalyst qw/
-Debug
ConfigLoader
Static::Simple
- Dumper
StackTrace
- DefaultEnd
Authentication
Authentication::Store::DBIC
The three C<Authentication> plugins work together to support
Authentication while the C<Session> plugins are required to maintain
state across multiple HTTP requests. Note that there are several
-options for L<Session::Store|Catalyst::Plugin::Session::Store> (although
-L<Session::Store::FastMmap|Catalyst::Plugin::Session::Store::FastMmap>
+options for L<Session::Store|Catalyst::Plugin::Session::Store>
+(L<Session::Store::FastMmap|Catalyst::Plugin::Session::Store::FastMmap>
is generally a good choice if you are on Unix; try
L<Cache::FileCache|Catalyst::Plugin::Cache::FileCache> if you are on
Win32) -- consult L<Session::Store|Catalyst::Plugin::Session::Store> and
Although C<__PACKAGE__-E<gt>config(name =E<gt> 'value');> is still
supported, newer Catalyst applications tend to place all configuration
information in C<myapp.yml> and automatically load this information into
-C<MyApp-E<gt>config> using the
-L<ConfigLoader|Catalyst::Plugin::ConfigLoader> plugin.
-
-Edit the C<myapp.yml> YAML and update it to match:
+C<MyApp-E<gt>config> using the
+L<ConfigLoader|Catalyst::Plugin::ConfigLoader> plugin. Here, we need
+to load several parameters that tell
+L<Catalyst::Plugin::Authentication|Catalyst::Plugin::Authentication>
+where to locate information in your database. To do this, edit the
+C<myapp.yml> YAML and update it to match:
---
name: MyApp
# This is the model object created by Catalyst::Model::DBIC from your
# schema (you created 'MyAppDB::User' but as the Catalyst startup
# debug messages show, it was loaded as 'MyApp::Model::MyAppDB::User').
- # NOTE: Omit 'MyAppDB::Model' to avoid a component lookup issue in Catalyst 5.66
+ # NOTE: Omit 'MyApp::Model' to avoid a component lookup issue in Catalyst 5.66
user_class: MyAppDB::User
# This is the name of the field in your 'users' table that contains the user's name
user_field: username
actions. Remember, Catalyst is designed to be very flexible, and leaves
such matters up to you, the designer and programmer.
-Then open C<lib/MyApp/Controller/Login.pm> and add:
+Then open C<lib/MyApp/Controller/Login.pm>, locate the C<sub index :
+Private> method (this was automatically inserted by the helpers when we
+created the Login controller above), and delete this line:
+
+ $c->response->body('Matched MyApp::Controller::Login in Login.');
+
+Then update it to match:
- =head2 default
+ =head2 index
Login logic
=cut
- sub default : Private {
+ sub index : Private {
my ($self, $c) = @_;
# Get the username and password from form
C<password> values are not present in the form, the user will be taken
to the empty login form.
-Next, create a corresponding method in C<lib/MyApp/Controller/Logout.pm>:
-
- =head2 default
+Note that we could have used something like C<sub default :Private>;
+however, the use of C<default> actions is discouraged because it does
+not receive path args as with other actions. The recommended practice
+is to only use C<default> in C<MyApp::Controller::Root>.
+
+Another option would be to use something like
+C<sub base :Path :Args(0) {...}> (where the C<...> refers to the login
+code shown in C<sub index : Private> above). We are using C<sub base
+:Path :Args(0) {...}> here to specifically match the URL C</login>.
+C<Path> actions (aka, "literal actions") create URI matches relative to
+the namespace of the controller where they are defined. Although
+C<Path> supports arguments that allow relative and absolute paths to be
+defined, here we use an empty C<Path> definition to match on just the
+name of the controller itself. The method name, C<base>, is arbitrary.
+We make the match even more specific with the C<:Args(0)> action
+modifier -- this forces the match on I<only> C</login>, not
+C</login/somethingelse>.
+
+Next, update the corresponding method in C<lib/MyApp/Controller/Logout.pm>
+to match:
+
+ =head2 index
Logout logic
=cut
- sub default : Private {
+ sub index : Private {
my ($self, $c) = @_;
# Clear the user's state
$c->logout;
- # Send the user to the starting
+ # Send the user to the starting point
$c->response->redirect($c->uri_for('/'));
}
+As with the login controller, be sure to delete the
+C<$c->response->body('Matched MyApp::Controller::Logout in Logout.');>
+line of the C<sub index>.
+
=head2 Add a Login Form TT Template Page
v5.66, this sort of thing would go in C<MyApp.pm>, but starting in
v5.66, the preferred location is C<lib/MyApp/Controller/Root.pm>).
-Edit the existing C<lib/MyApp/Controller/Root.pm> class file and insert the following method:
+Edit the existing C<lib/MyApp/Controller/Root.pm> class file and insert
+the following method:
=head2 auto
# Note that 'auto' runs after 'begin' but before your actions and that
# 'auto' "chain" (all from application path to most specific class are run)
+ # See the 'Actions' section of 'Catalyst::Manual::Intro' for more info.
sub auto : Private {
my ($self, $c) = @_;
- # Allow unauthenticated users to reach the login page
- if ($c->request->path =~ /login/) {
+ # Allow unauthenticated users to reach the login page. This
+ # allows anauthenticated users to reach any action in the Login
+ # controller. To lock it down to a single action, we could use:
+ # if ($c->action eq $c->controller('Login')->action_for('index'))
+ # to only allow unauthenticated access to the C<index> action we
+ # added above.
+ if ($c->controller eq $c->controller('Login')) {
return 1;
}
B<Note:> Catalyst provides a number of different types of actions, such
as C<Local>, C<Regex>, and C<Private>. You should refer to
-L<Catalyst::Manual::Intro|Catalyst::Manual::Intro> for a more detailed
-explanation, but the following bullet points provide a quick
-introduction:
+L<Catalyst::Manual::Intro> for a more detailed explanation, but the
+following bullet points provide a quick introduction:
=over 4
=item *
-Unlike the other private C<Private> actions where only a single method
-is called for each request, I<every> auto action along the chain of
-namespaces will be called.
+With C<begin>, C<end>, C<default>, C<index> private actions, only the
+most specific action of each type will be called. For example, if you
+define a C<begin> action in your controller it will I<override> a
+C<begin> action in your application/root controller -- I<only> the
+action in your controller will be called.
+
+=item *
+
+Unlike the other actions where only a single method is called for each
+request, I<every> auto action along the chain of namespaces will be
+called. Each C<auto> action will be called I<from the application/root
+controller down through the most specific class>.
=back
# This code illustrates how certain parts of the TT
# template will only be shown to users who have logged in
%]
- [% IF Catalyst.user %]
+ [% IF Catalyst.user_exists %]
Please Note: You are already logged in as '[% Catalyst.user.username %]'.
You can <a href="[% Catalyst.uri_for('/logout') %]">logout</a> here.
[% ELSE %]
Now trying going to L<http://localhost:3000/books/list> and you should
be redirected to the login page, hitting Shift+Reload if necessary (the
"You are already logged in" message should I<not> appear -- if it does,
-click the C<logout> button and try again). Make note of the
-C<***Root::auto User not found...> debug message in the development
-server output. Enter username C<test01> and password C<mypass>, and you
-should be taken to the Book List page.
+click the C<logout> button and try again). Note the C<***Root::auto User
+not found...> debug message in the development server output. Enter
+username C<test01> and password C<mypass>, and you should be taken to
+the Book List page.
-Open C< root/src/books/list.tt2> and add the following lines to the bottom:
+Open C<root/src/books/list.tt2> and add the following lines to the
+bottom:
<p>
<a href="[% Catalyst.uri_for('/login') %]">Login</a>
<a href="[% Catalyst.uri_for('form_create') %]">Create</a>
</p>
-Reload your browser and you should now see a "Login" link at the bottom
-of the page (as mentioned earlier, you can update template files without
-reloading the development server). Click this link to return to the
-login page. This time you I<should> see the "You are already logged in"
-message.
+Reload your browser and you should now see a "Login" and "Create" links
+at the bottom of the page (as mentioned earlier, you can update template
+files without reloading the development server). Click the first link
+to return to the login page. This time you I<should> see the "You are
+already logged in" message.
Finally, click the C<You can logout here> link on the C</login> page.
You should stay at the login page, but the message should change to "You
need to log in to use this application."
-
=head1 USING PASSWORD HASHES
In this section we increase the security of our system by converting
Note that even with the techniques shown in this section, the browser
still transmits the passwords in cleartext to your application. We are
just avoiding the I<storage> of cleartext passwords in the database by
-using a SHA-1 hash. If you are concerned about cleartext passwords
-between the browser and your application, consider using SSL/TLS.
+using a SHA-1 hash. If you are concerned about cleartext passwords
+between the browser and your application, consider using SSL/TLS, made
+easy with the Catalyst plugin Catalyst::Plugin:RequireSSL.
=head2 Get a SHA-1 Hash for the Password
e727d1464ae12436e899a726da5b2f11d8381b26
$
+B<Note:> You should probably modify this code for production use to
+not read the password from the command line. By having the script
+prompt for the cleartext password, it avoids having the password linger
+in forms such as your C<.bash_history> files (assuming you are using
+BASH as your shell). An example of such a script can be found in
+Appendix 3.
+
=head2 Switch to SHA-1 Password Hashes in the Database
# This is the model object created by Catalyst::Model::DBIC from your
# schema (you created 'MyAppDB::User' but as the Catalyst startup
# debug messages show, it was loaded as 'MyApp::Model::MyAppDB::User').
- # NOTE: Omit 'MyAppDB::Model' to avoid a component lookup issue in Catalyst 5.66
+ # NOTE: Omit 'MyApp::Model' here just as you would when using
+ # '$c->model("MyAppDB::User)'
user_class: MyAppDB::User
# This is the name of the field in your 'users' table that contains the user's name
user_field: username
login as before. When done, click the "Logout" link on the login page
(or point your browser at L<http://localhost:3000/logout>).
-=head1 AUTHOR
+B<Note:> If you receive the debug screen in your browser with a
+C<Can't call method "stash" on an undefined value...> error message,
+make sure that you are using v0.07 of
+L<Catalyst::Plugin::Authorization::ACL|Catalyst::Plugin::Authorization::ACL>.
+The following command can be a useful way to quickly dump the version number
+of this module on your system:
+
+ perl -MCatalyst::Plugin::Authorization::ACL -e 'print $Catalyst::Plugin::Authorization::ACL::VERSION, "\n";'
-Kennedy Clark, C<hkclark@gmail.com>
-Please report any errors, issues or suggestions to the author.
+=head1 USING THE SESSION FOR FLASH
-Copyright 2006, Kennedy Clark. All rights reserved.
+As discussed in Part 3 of the tutorial, C<flash> allows you to set
+variables in a way that is very similar to C<stash>, but it will
+remain set across multiple requests. Once the value is read, it
+is cleared (unless reset). Although C<flash> has nothing to do with
+authentication, it does leverage the same session plugins. Now that
+those plugins are enabled, let's go back and improve the "delete
+and redirect with query parameters" code seen at the end of the
+L<Basic CRUD|Catalyst::Manual::Tutorial::BasicCRUD> part of the
+tutorial.
-This library is free software; you can redistribute it and/or modify it
-under the same terms as Perl itself.
+First, open C<lib/MyApp/Controller/Books.pm> and modify C<sub delete>
+to match the following:
+
+ =head2 delete
+
+ Delete a book
+
+ =cut
+
+ sub delete : Local {
+ # $id = primary key of book to delete
+ my ($self, $c, $id) = @_;
+
+ # Search for the book and then delete it
+ $c->model('MyAppDB::Book')->search({id => $id})->delete_all;
+
+ # Use 'flash' to save information across requests until it's read
+ $c->flash->{status_msg} = "Book deleted";
+
+ # Redirect the user back to the list page with status msg as an arg
+ $c->response->redirect($c->uri_for('/books/list'));
+ }
+
+Next, open C<root/lib/site/layout> and update the TT code to pull from
+flash vs. the C<status_msg> query parameter:
+
+ <div id="header">[% PROCESS site/header %]</div>
+
+ <div id="content">
+ <span class="message">[% status_msg || Catalyst.flash.status_msg %]</span>
+ <span class="error">[% error_msg %]</span>
+ [% content %]
+ </div>
+
+ <div id="footer">[% PROCESS site/footer %]</div>
+
+
+=head2 Try Out Flash
+
+Restart the development server and point your browser to
+L<http://localhost:3000/books/url_create/Test/1/4> to create an extra
+book. Click the "Return to list" link and delete the "Test" book you
+just added. The C<flash> mechanism should retain our "Book deleted"
+status message across the redirect.
+
+B<NOTE:> While C<flash> will save information across multiple requests,
+I<it does get cleared the first time it is read>. In general, this is
+exactly what you want -- the C<flash> message will get displayed on
+the next screen where it's appropriate, but it won't "keep showing up"
+after that first time (unless you reset it). Please refer to
+L<Catalyst::Plugin::Session|Catalyst::Plugin::Session> for additional
+information.
+
+
+=head1 AUTHOR
+
+Kennedy Clark, C<hkclark@gmail.com>
-Version: .94
+Please report any errors, issues or suggestions to the author. The
+most recent version of the Catalyst Tutorial can be found at
+L<http://dev.catalyst.perl.org/repos/Catalyst/trunk/Catalyst-Runtime/lib/Catalyst/Manual/Tutorial/>.
+Copyright 2006, Kennedy Clark, under Creative Commons License
+(L<http://creativecommons.org/licenses/by-nc-sa/2.5/>).