Catalyst::Manual::Tutorial::05_Authentication - Catalyst Tutorial - Chapter 5: Authentication
-
=head1 OVERVIEW
This is B<Chapter 5 of 10> for the Catalyst tutorial.
This chapter of the tutorial is divided into two main sections: 1)
basic, cleartext authentication and 2) hash-based authentication.
-You can checkout the source code for this example from the catalyst
-subversion repository as per the instructions in
+Source code for the tutorial in included in the F</home/catalyst/Final> directory
+of the Tutorial Virtual machine (one subdirectory per chapter). There
+are also instructions for downloading the code in
L<Catalyst::Manual::Tutorial::01_Intro>.
-
=head1 BASIC AUTHENTICATION
This section explores how to add authentication logic to a Catalyst
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, Chapter 6). Create a new SQL script file by
-opening C<myapp02.sql> in your editor and insert:
+opening F<myapp02.sql> in your editor and insert:
--
-- Add users and role tables, along with a many-to-many join table
INSERT INTO user_role VALUES (2, 1);
INSERT INTO user_role VALUES (3, 1);
-Then load this into the C<myapp.db> database with the following command:
+Then load this into the F<myapp.db> database with the following command:
$ sqlite3 myapp.db < myapp02.sql
$ script/myapp_create.pl model DB DBIC::Schema MyApp::Schema \
create=static components=TimeStamp dbi:SQLite:myapp.db \
on_connect_do="PRAGMA foreign_keys = ON"
- exists "/root/dev/MyApp/script/../lib/MyApp/Model"
- exists "/root/dev/MyApp/script/../t"
- Dumping manual schema for MyApp::Schema to directory /root/dev/MyApp/script/../lib ...
+ exists "/home/catalyst/dev/MyApp/script/../lib/MyApp/Model"
+ exists "/home/catalyst/dev/MyApp/script/../t"
+ Dumping manual schema for MyApp::Schema to directory /home/catalyst/dev/MyApp/script/../lib ...
Schema dump completed.
- exists "/root/dev/MyApp/script/../lib/MyApp/Model/DB.pm"
+ exists "/home/catalyst/dev/MyApp/script/../lib/MyApp/Model/DB.pm"
$
$ ls lib/MyApp/Schema/Result
Author.pm BookAuthor.pm Book.pm Role.pm User.pm UserRole.pm
Notice how the helper has added three new table-specific Result Source
-files to the C<lib/MyApp/Schema/Result> directory. And, more
+files to the F<lib/MyApp/Schema/Result> directory. And, more
importantly, even if there were changes to the existing result source
-files, those changes would have only been written above the C<# DO NOT
-MODIFY THIS OR ANYTHING ABOVE!> comment and your hand-edited
+files, those changes would have only been written above the
+C<# DO NOT MODIFY THIS OR ANYTHING ABOVE!> comment and your hand-edited
enhancements would have been preserved.
Speaking of "hand-edited enhancements," we should now add the
C<many_to_many> relationship information to the User Result Source file.
-As with the Book, BookAuthor, and Author files in L<Chapter
-3|Catalyst::Manual::Tutorial::03_MoreCatalystBasics>,
+As with the Book, BookAuthor, and Author files in
+L<Chapter 3|Catalyst::Manual::Tutorial::03_MoreCatalystBasics>,
L<DBIx::Class::Schema::Loader> has automatically created the C<has_many>
and C<belongs_to> relationships for the new User, UserRole, and Role
tables. However, as a convenience for mapping Users to their assigned
roles (see L<Chapter 6|Catalyst::Manual::Tutorial::06_Authorization>),
we will also manually add a C<many_to_many> relationship. Edit
-C<lib/MyApp/Schema/Result/User.pm> add the following information between
+F<lib/MyApp/Schema/Result/User.pm> add the following information between
the C<# DO NOT MODIFY THIS OR ANYTHING ABOVE!> comment and the closing
C<1;>:
# 2) Name of has_many() relationship this many_to_many() is shortcut for
# 3) Name of belongs_to() relationship in model class of has_many() above
# You must already have the has_many() defined to use a many_to_many().
- __PACKAGE__->many_to_many(roles => 'user_roles', 'role_id');
+ __PACKAGE__->many_to_many(roles => 'user_roles', 'role');
The code for this update is obviously very similar to the edits we made
-to the C<Book> and C<Author> classes created in Chapter 3 with one
+to the C<Book> and C<Author> classes created in
+L<Chapter 3|Catalyst::Manual::Tutorial::03_MoreCatalystBasics> with one
exception: we only defined the C<many_to_many> relationship in one
direction. Whereas we felt that we would want to map Authors to Books
B<AND> Books to Authors, here we are only adding the convenience
C<many_to_many> in the Users to Roles direction.
Note that we do not need to make any change to the
-C<lib/MyApp/Schema.pm> schema file. It simply tells DBIC to load all of
-the Result Class and ResultSet Class files it finds in below the
-C<lib/MyApp/Schema> directory, so it will automatically pick up our new
+F<lib/MyApp/Schema.pm> schema file. It simply tells DBIC to load all of
+the Result Class and ResultSet Class files it finds below the
+F<lib/MyApp/Schema> directory, so it will automatically pick up our new
table information.
We aren't ready to try out the authentication just yet; we only want to
do a quick check to be sure our model loads correctly. Assuming that you
-are following along and using the "-r" option on C<myapp_server.pl>,
+are following along and using the "-r" option on F<myapp_server.pl>,
then the development server should automatically reload (if not, press
C<Ctrl-C> to break out of the server if it's running and then enter
-C<script/myapp_server.pl> to start it). Look for the three new model
+F<script/myapp_server.pl> to start it). Look for the three new model
objects in the startup debug output:
...
- .-------------------------------------------------------------------+----------.
+ .-------------------------------------------------------------------+----------.
| Class | Type |
+-------------------------------------------------------------------+----------+
| MyApp::Controller::Books | instance |
=head2 Include Authentication and Session Plugins
-Edit C<lib/MyApp.pm> and update it as follows (everything below
+Edit F<lib/MyApp.pm> and update it as follows (everything below
C<StackTrace> is new):
# Load plugins
-Debug
ConfigLoader
Static::Simple
-
+
StackTrace
-
+
Authentication
-
+
Session
Session::Store::File
Session::State::Cookie
/;
-B<Note:> As discussed in MoreCatalystBasics, different versions of
-C<Catalyst::Devel> have used a variety of methods to load the plugins,
-but we are going to use the current Catalyst 5.8X practice of putting
-them on the C<use Catalyst> line.
+B<Note:> As discussed in
+L<Chapter 3|Catalyst::Manual::Tutorial::03_MoreCatalystBasics>,
+different versions of C<Catalyst::Devel> have used a variety of methods
+to load the plugins, but we are going to use the current Catalyst 5.9
+practice of putting them on the C<use Catalyst> line.
The C<Authentication> plugin supports Authentication while the
C<Session> plugins are required to maintain state across multiple HTTP
requests.
Note that the only required Authentication class is the main one. This
-is a change that occurred in version 0.09999_01 of the C<Authentication>
-plugin. You B<do not need> to specify a particular Authentication::Store
-or Authentication::Credential plugin. Instead, indicate the Store and
-Credential you want to use in your application configuration (see
-below).
+is a change that occurred in version 0.09999_01 of the
+L<Authentication|Catalyst::Plugin::Authentication> plugin. You
+B<do not need> to specify a particular
+L<Authentication::Store|Catalyst::Authentication::Store> or
+C<Authentication::Credential> you want to use. Instead, indicate the
+Store and Credential you want to use in your application configuration
+(see below).
Make sure you include the additional plugins as new dependencies in the
Makefile.PL file something like this:
Windows L<Session::Store::File|Catalyst::Plugin::Session::Store::File>
is fine. Consult L<Session::Store|Catalyst::Plugin::Session::Store> and
its subclasses for additional information and options (for example to
-use a database- backed session store).
+use a database-backed session store).
=head2 Configure Authentication
There are a variety of ways to provide configuration information to
L<Catalyst::Plugin::Authentication>. Here we will use
L<Catalyst::Authentication::Realm::SimpleDB> because it automatically
-sets a reasonable set of defaults for us. Open C<lib/MyApp.pm> and place
-the following text above the call to C<__PACKAGE__-E<gt>setup();>:
+sets a reasonable set of defaults for us. (Note: the C<SimpleDB> here
+has nothing to do with the SimpleDB offered in Amazon's web services
+offerings -- here we are only talking about a "simple" way to use your
+DB as an authentication backend.) Open F<lib/MyApp.pm> and place the
+following text above the call to C<< __PACKAGE__->setup(); >>:
# Configure SimpleDB Authentication
__PACKAGE__->config(
},
);
-We could have placed this configuration in C<myapp.conf>, but placing it
-in C<lib/MyApp.pm> is probably a better place since it's not likely
+We could have placed this configuration in F<myapp.conf>, but placing it
+in F<lib/MyApp.pm> is probably a better place since it's not likely
something that users of your application will want to change during
deployment (or you could use a mixture: leave C<class> and C<user_model>
-defined in C<lib/MyApp.pm> as we show above, but place C<password_type>
-in C<myapp.conf> to allow the type of password to be easily modified
+defined in F<lib/MyApp.pm> as we show above, but place C<password_type>
+in F<myapp.conf> to allow the type of password to be easily modified
during deployment). We will stick with putting all of the
-authentication-related configuration in C<lib/MyApp.pm> for the
-tutorial, but if you wish to use C<myapp.conf>, just convert to the
+authentication-related configuration in F<lib/MyApp.pm> for the
+tutorial, but if you wish to use F<myapp.conf>, just convert to the
following code:
<Plugin::Authentication>
</Plugin::Authentication>
B<TIP:> Here is a short script that will dump the contents of
-C<MyApp->config> to L<Config::General> format in C<myapp.conf>:
+C<< MyApp->config >> to L<Config::General> format in F<myapp.conf>:
$ CATALYST_DEBUG=0 perl -Ilib -e 'use MyApp; use Config::General;
Config::General->new->save_file("myapp.conf", MyApp->config);'
"myapp.conf" command. Otherwise, you will wind up with duplicate
configurations.
-B<NOTE:> Because we are using SimpleDB along with a database layout that
-complies with its default assumptions: we don't need to specify the
-names of the columns where our username and password information is
-stored (hence, the "Simple" part of "SimpleDB"). That being said,
-SimpleDB lets you specify that type of information if you need to. Take
-a look at
-C<Catalyst::Authentication::Realm::SimpleDB|Catalyst::Authentication::Realm::SimpleDB>
+B<NOTE:> Because we are using
+L<SimpleDB|Catalyst::Authentication::Realm::SimpleDB> along with a
+database layout that complies with its default assumptions: we don't
+need to specify the names of the columns where our username and password
+information is stored (hence, the "Simple" part of "SimpleDB"). That
+being said, SimpleDB lets you specify that type of information if you
+need to. Take a look at C<Catalyst::Authentication::Realm::SimpleDB>
for details.
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>, locate the
-C<sub index :Path :Args(0)> method (or C<sub index : Private> if you are
-using an older version of Catalyst) that was automatically inserted by
-the helpers when we created the Login controller above, and update the
-definition of C<sub index> to match:
+Then open F<lib/MyApp/Controller/Login.pm>, and update the definition of
+C<sub index> to match:
=head2 index
-
+
Login logic
-
+
=cut
-
+
sub index :Path :Args(0) {
my ($self, $c) = @_;
-
+
# Get the username and password from form
my $username = $c->request->params->{username};
my $password = $c->request->params->{password};
-
+
# If the username and password values were found in form
if ($username && $password) {
# Attempt to log the user in
$c->stash(error_msg => "Empty username or password.")
unless ($c->user_exists);
}
-
+
# If either of above don't work out, send to the login page
$c->stash(template => 'login.tt2');
}
-Be sure to remove the
-C<$c-E<gt>response-E<gt>body('Matched MyApp::Controller::Login in Login.');>
-line of the C<sub index>.
-
This controller fetches the C<username> and C<password> values from the
login form and attempts to authenticate the user. If successful, it
redirects the user to the book list page. If the login fails, the user
on I<only> C</login>, not C</login/somethingelse>.
Next, update the corresponding method in
-C<lib/MyApp/Controller/Logout.pm> to match:
+F<lib/MyApp/Controller/Logout.pm> to match:
=head2 index
-
+
Logout logic
-
+
=cut
-
+
sub index :Path :Args(0) {
my ($self, $c) = @_;
-
+
# Clear the user's state
$c->logout;
-
+
# Send the user to the starting point
$c->response->redirect($c->uri_for('/'));
}
-As with the login controller, be sure to delete the
-C<$c-E<gt>response-E<gt>body('Matched MyApp::Controller::Logout in Logout.');>
-line of the C<sub index>.
-
=head2 Add a Login Form TT Template Page
-Create a login form by opening C<root/src/login.tt2> and inserting:
+Create a login form by opening F<root/src/login.tt2> and inserting:
[% META title = 'Login' %]
-
+
<!-- Login form -->
<form method="post" action="[% c.uri_for('/login') %]">
<table>
mechanism -- a I<global> mechanism that prevents users who have not
passed authentication from reaching any pages except the login page.
This is generally done via an C<auto> action/method in
-C<lib/MyApp/Controller/Root.pm>.
+F<lib/MyApp/Controller/Root.pm>.
-Edit the existing C<lib/MyApp/Controller/Root.pm> class file and insert
+Edit the existing F<lib/MyApp/Controller/Root.pm> class file and insert
the following method:
=head2 auto
-
+
Check if there is a user and, if not, forward to login page
-
+
=cut
-
+
# Note that 'auto' runs after 'begin' but before your actions and that
# 'auto's "chain" (all from application path to most specific class are run)
# See the 'Actions' section of 'Catalyst::Manual::Intro' for more info.
sub auto :Private {
my ($self, $c) = @_;
-
+
# Allow unauthenticated users to reach the login page. This
# allows unauthenticated users to reach any action in the Login
# controller. To lock it down to a single action, we could use:
if ($c->controller eq $c->controller('Login')) {
return 1;
}
-
+
# If a user doesn't exist, force login
if (!$c->user_exists) {
# Dump a log message to the development server debug output
# Return 0 to cancel 'post-auto' processing and prevent use of application
return 0;
}
-
+
# User found, so return 1 to continue with processing after this 'auto'
return 1;
}
every C<auto> method from the application/root controller down to the
most specific controller will be called. By placing the authentication
enforcement code inside the C<auto> method of
-C<lib/MyApp/Controller/Root.pm> (or C<lib/MyApp.pm>), it will be called
+F<lib/MyApp/Controller/Root.pm> (or F<lib/MyApp.pm>), it will be called
for I<every> request that is received by the entire application.
Let's say you want to provide some information on the login page that
changes depending on whether the user has authenticated yet. To do
-this, open C<root/src/login.tt2> in your editor and add the following
+this, open F<root/src/login.tt2> in your editor and add the following
lines to the bottom of the file:
...
List page.
B<IMPORTANT NOTE:> If you are having issues with authentication on
-Internet Explorer, be sure to check the system clocks on both your
-server and client machines. Internet Explorer is very picky about
-timestamps for cookies. You can quickly sync a Debian system by
-installing the "ntpdate" package:
-
- sudo aptitude -y install ntpdate
-
-And then run the following command:
+Internet Explorer (or potentially other browsers), be sure to check the
+system clocks on both your server and client machines. Internet
+Explorer is very picky about timestamps for cookies. You can use the
+C<ntpq -p> command on the Tutorial Virtual Machine to check time sync
+and/or use the following command to force a sync:
sudo ntpdate-debian
-Or, depending on your firewall configuration:
+Or, depending on your firewall configuration, try it with "-u":
sudo ntpdate-debian -u
Worse case, you might have to manually set the time on your development
box instead of using NTP.
-Open C<root/src/books/list.tt2> and add the following lines to the
+Open F<root/src/books/list.tt2> and add the following lines to the
bottom (below the closing </table> tag):
...
In this section we increase the security of our system by converting
from cleartext passwords to SHA-1 password hashes that include a random
-"salt" value to make them extremely difficult to crack with dictionary
-and "rainbow table" attacks.
+"salt" value to make them extremely difficult to crack, even with
+dictionary and "rainbow table" attacks.
B<Note:> This section is optional. You can skip it and the rest of the
tutorial will function normally.
We are just avoiding the I<storage> of cleartext passwords in the
database by using a salted 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
-L<Catalyst::Plugin:RequireSSL>.
+using SSL/TLS, made easy with modules such as
+L<Catalyst::Plugin::RequireSSL> and L<Catalyst::ActionRole::RequireSSL>.
=head2 Re-Run the DBIC::Schema Model Helper to Include DBIx::Class::PassphraseColumn
-Next, we can re-run the model helper to have it include
+Let's re-run the model helper to have it include
L<DBIx::Class::PassphraseColumn> in all of the Result Classes it
generates for us. Simply use the same command we saw in Chapters 3 and
4, but add C<,PassphraseColumn> to the C<components> argument:
If you then open one of the Result Classes, you will see that it
includes PassphraseColumn in the C<load_components> line. Take a look
-at C<lib/MyApp/Schema/Result/User.pm> since that's the main class where
+at F<lib/MyApp/Schema/Result/User.pm> since that's the main class where
we want to use hashed and salted passwords:
__PACKAGE__->load_components("InflateColumn::DateTime", "TimeStamp", "PassphraseColumn");
=head2 Modify the "password" Column to Use PassphraseColumn
-Open the file C<lib/MyApp/Schema/Result/User.pm> and enter the following
+Open the file F<lib/MyApp/Schema/Result/User.pm> and enter the following
text below the "# DO NOT MODIFY THIS OR ANYTHING ABOVE!" line but above
the closing "1;":
passphrase_class => 'SaltedDigest',
passphrase_args => {
algorithm => 'SHA-1',
- salt_random => 20.
+ salt_random => 20,
},
passphrase_check_method => 'check_password',
},
Next, let's create a quick script to load some hashed and salted
passwords into the C<password> column of our C<users> table. Open the
-file C<set_hashed_passwords.pl> in your editor and enter the following
+file F<set_hashed_passwords.pl> in your editor and enter the following
text:
#!/usr/bin/perl
-
+
use strict;
use warnings;
-
+
use MyApp::Schema;
-
+
my $schema = MyApp::Schema->connect('dbi:SQLite:myapp.db');
-
+
my @users = $schema->resultset('User')->all;
-
+
foreach my $user (@users) {
$user->password('mypass');
$user->update;
}
-PassphraseColumn lets us simply call C<$user->check_password($password)>
+PassphraseColumn lets us simply call C<< $user->check_password($password) >>
to see if the user has supplied the correct password, or, as we show
-above, call C<$user->update($new_password)> to update the hashed
+above, call C<< $user->update($new_password) >> to update the hashed
password stored for this user.
Then run the following command:
$ DBIC_TRACE=1 perl -Ilib set_hashed_passwords.pl
-We had to use the C<-Ilib> argument to tell perl to look under the
-C<lib> directory for our C<MyApp::Schema> model.
+We had to use the C<-Ilib> argument to tell Perl to look under the
+F<lib> directory for our C<MyApp::Schema> model.
The DBIC_TRACE output should show that the update worked:
=head2 Enable Hashed and Salted Passwords
-Edit C<lib/MyApp.pm> and update it to match the following text (the only
+Edit F<lib/MyApp.pm> and update the config() section for
+C<Plugin::Authentication> it to match the following text (the only
change is to the C<password_type> field):
# Configure SimpleDB Authentication
);
The use of C<self_check> will cause
-Catalyst::Plugin::Authentication::Store::DBIC to call the
+Catalyst::Plugin::Authentication::Store::DBIx::Class to call the
C<check_password> method we enabled on our C<password> columns.
-
=head2 Try Out the Hashed Passwords
The development server should restart as soon as your save the
-C<lib/MyApp.pm> file in the previous section. You should now be able to
+F<lib/MyApp.pm> file in the previous section. You should now be able to
go to L<http://localhost:3000/books/list> and login as before. When
done, click the "logout" link on the login page (or point your browser
at L<http://localhost:3000/logout>).
L<Basic CRUD|Catalyst::Manual::Tutorial::04_BasicCRUD> chapter of the
tutorial to take advantage of C<flash>.
-First, open C<lib/MyApp/Controller/Books.pm> and modify C<sub delete> to
+First, open F<lib/MyApp/Controller/Books.pm> and modify C<sub delete> to
match the following (everything after the model search line of code has
changed):
=head2 delete
-
+
Delete a book
-
+
=cut
-
+
sub delete :Chained('object') :PathPart('delete') :Args(0) {
my ($self, $c) = @_;
-
+
# Use the book object saved by 'object' and delete it along
# with related 'book_authors' entries
$c->stash->{object}->delete;
-
+
# 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
$c->response->redirect($c->uri_for($self->action_for('list')));
}
-Next, open C<root/src/wrapper.tt2> and update the TT code to pull from
+Next, open F<root/src/wrapper.tt2> and update the TT code to pull from
flash vs. the C<status_msg> query parameter:
...
...
Although the sample above only shows the C<content> div, leave the rest
-of the file intact -- the only change we made to replace "||
-c.request.params.status_msg" with "c.flash.status_msg" in the
-C<E<lt>span class="message"E<gt>> line.
+of the file intact -- the only change we made to replace "C<||
+c.request.params.status_msg>" with "C<c.flash.status_msg>" in the
+C<< <span class="message"> >> line.
=head2 Try Out Flash
that first time (unless you reset it). Please refer to
L<Catalyst::Plugin::Session> for additional information.
+B<Note:> There is also a C<flash-to-stash> feature that will
+automatically load the contents the contents of flash into stash,
+allowing us to use the more typical C<c.flash.status_msg> in our TT
+template in lieu of the more verbose C<status_msg || c.flash.status_msg>
+we used above. Consult L<Catalyst::Plugin::Session> for additional
+information.
+
+
+=head2 Switch To Catalyst::Plugin::StatusMessages
+
+Although the query parameter technique we used in
+L<Chapter 4|Catalyst::Manual::Tutorial::04_BasicCRUD> and the C<flash>
+approach we used above will work in most cases, they both have their
+drawbacks. The query parameters can leave the status message on the
+screen longer than it should (for example, if the user hits refresh).
+And C<flash> can display the wrong message on the wrong screen (flash
+just shows the message on the next page for that user... if the user
+has multiple windows or tabs open, then the wrong one can get the
+status message).
+
+L<Catalyst::Plugin::StatusMessage> is designed to address these
+shortcomings. It stores the messages in the user's session (so they are
+available across multiple requests), but ties each status message to a
+random token. By passing this token across the redirect, we are no
+longer relying on a potentially ambiguous "next request" like we do with
+flash. And, because the message is deleted the first time it's
+displayed, the user can hit refresh and still only see the message a
+single time (even though the URL may continue to reference the token,
+it's only displayed the first time). The use of C<StatusMessage>
+or a similar mechanism is recommended for all Catalyst applications.
+
+To enable C<StatusMessage>, first edit F<lib/MyApp.pm> and add
+C<StatusMessage> to the list of plugins:
+
+ use Catalyst qw/
+ -Debug
+ ConfigLoader
+ Static::Simple
-=head2 Switch To Flash-To-Stash
+ StackTrace
-Although the use of flash above works well, the
-C<status_msg || c.flash.status_msg> statement is a little ugly. A nice
-alternative is to use the C<flash_to_stash> feature that automatically
-copies the content of flash to stash. This makes your controller and
-template code work regardless of where it was directly access, a
-forward, or a redirect. To enable C<flash_to_stash>, you can either set
-the value in C<lib/MyApp.pm> by changing the default
-C<__PACKAGE__-E<gt>config> setting to something like:
+ Authentication
- __PACKAGE__->config(
- name => 'MyApp',
- # Disable deprecated behavior needed by old applications
- disable_component_resolution_regex_fallback => 1,
- 'Plugin::Session' => { flash_to_stash => 1 },
- );
+ Session
+ Session::Store::File
+ Session::State::Cookie
-B<or> add the following to C<myapp.conf>:
+ StatusMessage
+ /;
- <Plugin::Session>
- flash_to_stash 1
- </Plugin::Session>
+Then edit F<lib/MyApp/Controller/Books.pm> and modify the C<delete>
+action to match the following:
-The C<__PACKAGE__-E<gt>config> option is probably preferable here since
-it's not something you will want to change at runtime without it
-possibly breaking some of your code.
+ sub delete :Chained('object') :PathPart('delete') :Args(0) {
+ my ($self, $c) = @_;
-Then edit C<root/src/wrapper.tt2> and change the C<status_msg> line to
-match the following:
+ # Saved the PK id for status_msg below
+ my $id = $c->stash->{object}->id;
+
+ # Use the book object saved by 'object' and delete it along
+ # with related 'book_authors' entries
+ $c->stash->{object}->delete;
- <span class="message">[% status_msg %]</span>
+ # Redirect the user back to the list page
+ $c->response->redirect($c->uri_for($self->action_for('list'),
+ {mid => $c->set_status_msg("Deleted book $id")}));
+ }
-Now go to L<http://localhost:3000/books/list> in your browser. Delete
-another of the "Test" books you added in the previous step. Flash should
-still maintain the status message across the redirect even though you
-are no longer explicitly accessing C<c.flash>.
+This uses the C<set_status_msg> that the plugin added to C<$c> to save
+the message under a random token. (If we wanted to save an error
+message, we could have used C<set_error_msg>.) Because
+C<set_status_msg> and C<set_error_msg> both return the random token, we
+can assign that value to the "C<mid>" query parameter via C<uri_for> as
+shown above.
+
+Next, we need to make sure that the list page will load display the
+message. The easiest way to do this is to take advantage of the chained
+dispatch we implemented in
+L<Chapter 4|Catalyst::Manual::Tutorial::04_BasicCRUD>. Edit
+F<lib/MyApp/Controller/Books.pm> again and update the C<base> action to
+match:
+
+ sub base :Chained('/') :PathPart('books') :CaptureArgs(0) {
+ my ($self, $c) = @_;
+
+ # Store the ResultSet in stash so it's available for other methods
+ $c->stash(resultset => $c->model('DB::Book'));
+
+ # Print a message to the debug log
+ $c->log->debug('*** INSIDE BASE METHOD ***');
+
+ # Load status messages
+ $c->load_status_msgs;
+ }
+
+That way, anything that chains off C<base> will automatically get any
+status or error messages loaded into the stash. Let's convert the
+C<list> action to take advantage of this. Modify the method signature
+for C<list> from:
+
+ sub list :Local {
+
+to:
+
+ sub list :Chained('base') :PathPart('list') :Args(0) {
+
+Finally, let's clean up the status/error message code in our wrapper
+template. Edit F<root/src/wrapper.tt2> and change the "content" div
+to match the following:
+ <div id="content">
+ [%# Status and error messages %]
+ <span class="message">[% status_msg %]</span>
+ <span class="error">[% error_msg %]</span>
+ [%# This is where TT will stick all of your template's contents. -%]
+ [% content %]
+ </div><!-- end content -->
+
+Now go to L<http://localhost:3000/books/list> in your browser. Delete
+another of the "Test" books you added in the previous step. You should
+get redirection from the C<delete> action back to the C<list> action,
+but with a "mid=########" message ID query parameter. The screen should
+say "Deleted book #" (where # is the PK id of the book you removed).
+However, if you hit refresh in your browser, the status message is no
+longer displayed (even though the URL does still contain the message ID
+token, it is ignored -- thereby keeping the state of our status/error
+messages in sync with the users actions).
+
+You can jump to the next chapter of the tutorial here:
+L<Authorization|Catalyst::Manual::Tutorial::06_Authorization>
=head1 AUTHOR
Feel free to contact the author for any errors or suggestions, but the
best way to report issues is via the CPAN RT Bug system at
-<https://rt.cpan.org/Public/Dist/Display.html?Name=Catalyst-Manual>.
-
-The most recent version of the Catalyst Tutorial can be found at
-L<http://dev.catalyst.perl.org/repos/Catalyst/Catalyst-Manual/5.80/trunk/lib/Catalyst/Manual/Tutorial/>.
+L<https://rt.cpan.org/Public/Dist/Display.html?Name=Catalyst-Manual>.
-Copyright 2006-2010, Kennedy Clark, under the
+Copyright 2006-2011, Kennedy Clark, under the
Creative Commons Attribution Share-Alike License Version 3.0
(L<http://creativecommons.org/licenses/by-sa/3.0/us/>).
projects / catagits/Catalyst-Manual.git / blobdiff