3 Catalyst::Manual::Tutorial::05_Authentication - Catalyst Tutorial - Chapter 5: Authentication
8 This is B<Chapter 5 of 10> for the Catalyst tutorial.
10 L<Tutorial Overview|Catalyst::Manual::Tutorial>
16 L<Introduction|Catalyst::Manual::Tutorial::01_Intro>
20 L<Catalyst Basics|Catalyst::Manual::Tutorial::02_CatalystBasics>
24 L<More Catalyst Basics|Catalyst::Manual::Tutorial::03_MoreCatalystBasics>
28 L<Basic CRUD|Catalyst::Manual::Tutorial::04_BasicCRUD>
36 L<Authorization|Catalyst::Manual::Tutorial::06_Authorization>
40 L<Debugging|Catalyst::Manual::Tutorial::07_Debugging>
44 L<Testing|Catalyst::Manual::Tutorial::08_Testing>
48 L<Advanced CRUD|Catalyst::Manual::Tutorial::09_AdvancedCRUD>
52 L<Appendices|Catalyst::Manual::Tutorial::10_Appendices>
59 Now that we finally have a simple yet functional application, we can
60 focus on providing authentication (with authorization coming next in
63 This chapter of the tutorial is divided into two main sections: 1) basic,
64 cleartext authentication and 2) hash-based authentication.
66 You can checkout the source code for this example from the catalyst
67 subversion repository as per the instructions in
68 L<Catalyst::Manual::Tutorial::01_Intro|Catalyst::Manual::Tutorial::01_Intro>.
71 =head1 BASIC AUTHENTICATION
73 This section explores how to add authentication logic to a Catalyst
77 =head2 Add Users and Roles to the Database
79 First, we add both user and role information to the database (we will
80 add the role information here although it will not be used until the
81 authorization section, Chapter 6). Create a new SQL script file by opening
82 C<myapp02.sql> in your editor and insert:
85 -- Add users and role tables, along with a many-to-many join table
87 PRAGMA foreign_keys = ON;
89 id INTEGER PRIMARY KEY,
98 id INTEGER PRIMARY KEY,
101 CREATE TABLE user_role (
102 user_id INTEGER REFERENCES user(id) ON DELETE CASCADE ON UPDATE CASCADE,
103 role_id INTEGER REFERENCES role(id) ON DELETE CASCADE ON UPDATE CASCADE,
104 PRIMARY KEY (user_id, role_id)
107 -- Load up some initial test data
109 INSERT INTO users VALUES (1, 'test01', 'mypass', 't01@na.com', 'Joe', 'Blow', 1);
110 INSERT INTO users VALUES (2, 'test02', 'mypass', 't02@na.com', 'Jane', 'Doe', 1);
111 INSERT INTO users VALUES (3, 'test03', 'mypass', 't03@na.com', 'No', 'Go', 0);
112 INSERT INTO role VALUES (1, 'user');
113 INSERT INTO role VALUES (2, 'admin');
114 INSERT INTO user_role VALUES (1, 1);
115 INSERT INTO user_role VALUES (1, 2);
116 INSERT INTO user_role VALUES (2, 1);
117 INSERT INTO user_role VALUES (3, 1);
119 Then load this into the C<myapp.db> database with the following command:
121 $ sqlite3 myapp.db < myapp02.sql
124 =head2 Add User and Role Information to DBIC Schema
126 Although we could manually edit the DBIC schema information to include
127 the new tables added in the previous step, let's use the C<create=static>
128 option on the DBIC model helper to do most of the work for us:
130 $ script/myapp_create.pl model DB DBIC::Schema MyApp::Schema \
131 create=static components=TimeStamp dbi:SQLite:myapp.db \
132 on_connect_do="PRAGMA foreign_keys = ON"
133 exists "/root/dev/MyApp/script/../lib/MyApp/Model"
134 exists "/root/dev/MyApp/script/../t"
135 Dumping manual schema for MyApp::Schema to directory /root/dev/MyApp/script/../lib ...
136 Schema dump completed.
137 exists "/root/dev/MyApp/script/../lib/MyApp/Model/DB.pm"
139 $ ls lib/MyApp/Schema/Result
140 Author.pm BookAuthor.pm Book.pm Role.pm User.pm UserRole.pm
142 Notice how the helper has added three new table-specific Result Source
143 files to the C<lib/MyApp/Schema/Result> directory. And, more
144 importantly, even if there were changes to the existing result source
145 files, those changes would have only been written above the C<# DO NOT
146 MODIFY THIS OR ANYTHING ABOVE!> comment and your hand-edited
147 enhancements would have been preserved.
149 Speaking of "hand-editted enhancements," we should now add the
150 C<many_to_many> relationship information to the User Result Source file.
151 As with the Book, BookAuthor, and Author files in
152 L<Chapter 3|Catalyst::Manual::Tutorial::03_MoreCatalystBasics>,
153 L<DBIx::Class::Schema::Loader|DBIx::Class::Schema::Loader> has
154 automatically created the C<has_many> and C<belongs_to> relationships
155 for the new User, UserRole, and Role tables. However, as a convenience
156 for mapping Users to their assigned roles (see
157 L<Chapter 6|Catalyst::Manual::Tutorial::06_Authorization>), we will
158 also manually add a C<many_to_many> relationship. Edit
159 C<lib/MyApp/Schema/Result/User.pm> add the following information between
160 the C<# DO NOT MODIFY THIS OR ANYTHING ABOVE!> comment and the closing
165 # 1) Name of relationship, DBIC will create accessor with this name
166 # 2) Name of has_many() relationship this many_to_many() is shortcut for
167 # 3) Name of belongs_to() relationship in model class of has_many() above
168 # You must already have the has_many() defined to use a many_to_many().
169 __PACKAGE__->many_to_many(roles => 'user_roles', 'role_id');
171 The code for this update is obviously very similar to the edits we made
172 to the C<Book> and C<Author> classes created in Chapter 3 with one
173 exception: we only defined the C<many_to_many> relationship in one
174 direction. Whereas we felt that we would want to map Authors to Books
175 B<AND> Books to Authors, here we are only adding the convenience
176 C<many_to_many> in the Users to Roles direction.
178 Note that we do not need to make any change to the
179 C<lib/MyApp/Schema.pm> schema file. It simply tells DBIC to load all
180 of the Result Class and ResultSet Class files it finds in below the
181 C<lib/MyApp/Schema> directory, so it will automatically pick up our
182 new table information.
185 =head2 Sanity-Check of the Development Server Reload
187 We aren't ready to try out the authentication just yet; we only want to
188 do a quick check to be sure our model loads correctly. Assuming that you
189 are following along and using the "-r" option on C<myapp_server.pl>,
190 then the development server should automatically reload (if not, press
191 C<Ctrl-C> to break out of the server if it's running and then enter
192 C<script/myapp_server.pl> to start it). Look for the three new model
193 objects in the startup debug output:
196 .-------------------------------------------------------------------+----------.
198 +-------------------------------------------------------------------+----------+
199 | MyApp::Controller::Books | instance |
200 | MyApp::Controller::Root | instance |
201 | MyApp::Model::DB | instance |
202 | MyApp::Model::DB::Author | class |
203 | MyApp::Model::DB::Book | class |
204 | MyApp::Model::DB::BookAuthor | class |
205 | MyApp::Model::DB::Role | class |
206 | MyApp::Model::DB::User | class |
207 | MyApp::Model::DB::UserRole | class |
208 | MyApp::View::HTML | instance |
209 '-------------------------------------------------------------------+----------'
212 Again, notice that your "Result Class" classes have been "re-loaded"
213 by Catalyst under C<MyApp::Model>.
216 =head2 Include Authentication and Session Plugins
218 Edit C<lib/MyApp.pm> and update it as follows (everything below
219 C<StackTrace> is new):
232 Session::Store::FastMmap
233 Session::State::Cookie
236 B<Note:> As discussed in MoreCatalystBasics, different versions of
237 C<Catalyst::Devel> have used a variety of methods to load the plugins,
238 but we are going to use the current Catalyst 5.8X practice of putting
239 them on the C<use Catalyst> line.
241 The C<Authentication> plugin supports Authentication while the
242 C<Session> plugins are required to maintain state across multiple HTTP
245 Note that the only required Authentication class is the main one. This
246 is a change that occurred in version 0.09999_01 of the
247 C<Authentication> plugin. You B<do not need> to specify a particular
248 Authentication::Store or Authentication::Credential plugin. Instead,
249 indicate the Store and Credential you want to use in your application
250 configuration (see below).
252 Make sure you include the additional plugins as new dependencies in
253 the Makefile.PL file something like this:
255 requires 'Catalyst::Plugin::Authentication';
256 requires 'Catalyst::Plugin::Session';
257 requires 'Catalyst::Plugin::Session::Store::FastMmap';
258 requires 'Catalyst::Plugin::Session::State::Cookie';
260 Note that there are several options for
261 L<Session::Store|Catalyst::Plugin::Session::Store>.
262 L<Session::Store::Memcached|Catalyst::Plugin::Session::Store::Memcached> or
263 L<Session::Store::FastMmap|Catalyst::Plugin::Session::Store::FastMmap> is
264 generally a good choice if you are on Unix. If you are running on
266 L<Session::Store::File|Catalyst::Plugin::Session::Store::File>. Consult
267 L<Session::Store|Catalyst::Plugin::Session::Store> and its subclasses
268 for additional information and options (for example to use a database-
269 backed session store).
272 =head2 Configure Authentication
274 There are a variety of ways to provide configuration information to
275 L<Catalyst::Plugin::Authentication|Catalyst::Plugin::Authentication>.
277 L<Catalyst::Authentication::Realm::SimpleDB|Catalyst::Authentication::Realm::SimpleDB>
278 because it automatically sets a reasonable set of defaults for us. Open
279 C<lib/MyApp.pm> and place the following text above the call to
280 C<__PACKAGE__-E<gt>setup();>:
282 # Configure SimpleDB Authentication
283 __PACKAGE__->config->{'Plugin::Authentication'} = {
286 user_model => 'DB::User',
287 password_type => 'clear',
291 We could have placed this configuration in C<myapp.conf>, but placing
292 it in C<lib/MyApp.pm> is probably a better place since it's not likely
293 something that users of your application will want to change during
294 deployment (or you could use a mixture: leave C<class> and
295 C<user_model> defined in C<lib/MyApp.pm> as we show above, but place
296 C<password_type> in C<myapp.conf> to allow the type of password to be
297 easily modified during deployment). We will stick with putting
298 all of the authentication-related configuration in C<lib/MyApp.pm>
299 for the tutorial, but if you wish to use C<myapp.conf>, just convert
300 to the following code:
302 <Plugin::Authentication>
308 </Plugin::Authentication>
310 B<TIP:> Here is a short script that will dump the contents of
311 C<MyApp->config> to L<Config::General|Config::General> format in
314 $ CATALYST_DEBUG=0 perl -Ilib -e 'use MyApp; use Config::General;
315 Config::General->new->save_file("myapp.conf", MyApp->config);'
317 B<HOWEVER>, if you try out the command above, be sure to delete the
318 "myapp.conf" command. Otherwise, you will wind up with duplicate
321 B<NOTE:> Because we are using SimpleDB along with a database layout
322 that complies with its default assumptions: we don't need to specify
323 the names of the columns where our username and password information
324 is stored (hence, the "Simple" part of "SimpleDB"). That being said,
325 SimpleDB lets you specify that type of information if you need to.
327 C<Catalyst::Authentication::Realm::SimpleDB|Catalyst::Authentication::Realm::SimpleDB>
331 =head2 Add Login and Logout Controllers
333 Use the Catalyst create script to create two stub controller files:
335 $ script/myapp_create.pl controller Login
336 $ script/myapp_create.pl controller Logout
338 You could easily use a single controller here. For example, you could
339 have a C<User> controller with both C<login> and C<logout> actions.
340 Remember, Catalyst is designed to be very flexible, and leaves such
341 matters up to you, the designer and programmer.
343 Then open C<lib/MyApp/Controller/Login.pm>, locate the
344 C<sub index :Path :Args(0)> method (or C<sub index : Private> if you
345 are using an older version of Catalyst) that was automatically
346 inserted by the helpers when we created the Login controller above,
347 and update the definition of C<sub index> to match:
355 sub index :Path :Args(0) {
358 # Get the username and password from form
359 my $username = $c->request->params->{username};
360 my $password = $c->request->params->{password};
362 # If the username and password values were found in form
363 if ($username && $password) {
364 # Attempt to log the user in
365 if ($c->authenticate({ username => $username,
366 password => $password } )) {
367 # If successful, then let them use the application
368 $c->response->redirect($c->uri_for(
369 $c->controller('Books')->action_for('list')));
372 # Set an error message
373 $c->stash(error_msg => "Bad username or password.");
376 # Set an error message
377 $c->stash(error_msg => "Empty username or password.")
378 unless ($c->user_exists);
381 # If either of above don't work out, send to the login page
382 $c->stash(template => 'login.tt2');
385 Be sure to remove the
386 C<$c-E<gt>response-E<gt>body('Matched MyApp::Controller::Login in Login.');>
387 line of the C<sub index>.
389 This controller fetches the C<username> and C<password> values from the
390 login form and attempts to authenticate the user. If successful, it
391 redirects the user to the book list page. If the login fails, the user
392 will stay at the login page and receive an error message. If the
393 C<username> and C<password> values are not present in the form, the
394 user will be taken to the empty login form.
396 Note that we could have used something like "C<sub default :Path>",
397 however, it is generally recommended (partly for historical reasons,
398 and partly for code clarity) only to use C<default> in
399 C<MyApp::Controller::Root>, and then mainly to generate the 404 not
400 found page for the application.
402 Instead, we are using "C<sub somename :Path :Args(0) {...}>" here to
403 specifically match the URL C</login>. C<Path> actions (aka, "literal
404 actions") create URI matches relative to the namespace of the
405 controller where they are defined. Although C<Path> supports
406 arguments that allow relative and absolute paths to be defined, here
407 we use an empty C<Path> definition to match on just the name of the
408 controller itself. The method name, C<index>, is arbitrary. We make
409 the match even more specific with the C<:Args(0)> action modifier --
410 this forces the match on I<only> C</login>, not
411 C</login/somethingelse>.
413 Next, update the corresponding method in
414 C<lib/MyApp/Controller/Logout.pm> to match:
422 sub index :Path :Args(0) {
425 # Clear the user's state
428 # Send the user to the starting point
429 $c->response->redirect($c->uri_for('/'));
432 As with the login controller, be sure to delete the
433 C<$c-E<gt>response-E<gt>body('Matched MyApp::Controller::Logout in Logout.');>
434 line of the C<sub index>.
437 =head2 Add a Login Form TT Template Page
439 Create a login form by opening C<root/src/login.tt2> and inserting:
441 [% META title = 'Login' %]
444 <form method="post" action="[% c.uri_for('/login') %]">
448 <td><input type="text" name="username" size="40" /></td>
452 <td><input type="password" name="password" size="40" /></td>
455 <td colspan="2"><input type="submit" name="submit" value="Submit" /></td>
461 =head2 Add Valid User Check
463 We need something that provides enforcement for the authentication
464 mechanism -- a I<global> mechanism that prevents users who have not
465 passed authentication from reaching any pages except the login page.
466 This is generally done via an C<auto> action/method in
467 C<lib/MyApp/Controller/Root.pm>.
469 Edit the existing C<lib/MyApp/Controller/Root.pm> class file and insert
470 the following method:
474 Check if there is a user and, if not, forward to login page
478 # Note that 'auto' runs after 'begin' but before your actions and that
479 # 'auto's "chain" (all from application path to most specific class are run)
480 # See the 'Actions' section of 'Catalyst::Manual::Intro' for more info.
484 # Allow unauthenticated users to reach the login page. This
485 # allows unauthenticated users to reach any action in the Login
486 # controller. To lock it down to a single action, we could use:
487 # if ($c->action eq $c->controller('Login')->action_for('index'))
488 # to only allow unauthenticated access to the 'index' action we
490 if ($c->controller eq $c->controller('Login')) {
494 # If a user doesn't exist, force login
495 if (!$c->user_exists) {
496 # Dump a log message to the development server debug output
497 $c->log->debug('***Root::auto User not found, forwarding to /login');
498 # Redirect the user to the login page
499 $c->response->redirect($c->uri_for('/login'));
500 # Return 0 to cancel 'post-auto' processing and prevent use of application
504 # User found, so return 1 to continue with processing after this 'auto'
509 L<Catalyst::Manual::Tutorial::03_MoreCatalystBasics/CREATE A CATALYST CONTROLLER>,
510 every C<auto> method from the application/root controller down to the
511 most specific controller will be called. By placing the
512 authentication enforcement code inside the C<auto> method of
513 C<lib/MyApp/Controller/Root.pm> (or C<lib/MyApp.pm>), it will be
514 called for I<every> request that is received by the entire
518 =head2 Displaying Content Only to Authenticated Users
520 Let's say you want to provide some information on the login page that
521 changes depending on whether the user has authenticated yet. To do
522 this, open C<root/src/login.tt2> in your editor and add the following
523 lines to the bottom of the file:
528 # This code illustrates how certain parts of the TT
529 # template will only be shown to users who have logged in
531 [% IF c.user_exists %]
532 Please Note: You are already logged in as '[% c.user.username %]'.
533 You can <a href="[% c.uri_for('/logout') %]">logout</a> here.
535 You need to log in to use this application.
538 Note that this whole block is a comment because the "#" appears
539 immediate after the "[%" (with no spaces in between). Although it
540 can be a handy way to temporarily "comment out" a whole block of
541 TT code, it's probably a little too subtle for use in "normal"
546 Although most of the code is comments, the middle few lines provide a
547 "you are already logged in" reminder if the user returns to the login
548 page after they have already authenticated. For users who have not yet
549 authenticated, a "You need to log in..." message is displayed (note the
550 use of an IF-THEN-ELSE construct in TT).
553 =head2 Try Out Authentication
555 The development server should have reloaded each time we edited one of
556 the Controllers in the previous section. Now try going to
557 L<http://localhost:3000/books/list> and you should be redirected to the
558 login page, hitting Shift+Reload or Ctrl+Reload if necessary (the "You
559 are already logged in" message should I<not> appear -- if it does, click
560 the C<logout> button and try again). Note the C<***Root::auto User not
561 found...> debug message in the development server output. Enter username
562 C<test01> and password C<mypass>, and you should be taken to the Book
565 B<IMPORTANT NOTE:> If you are having issues with authentication on
566 Internet Explorer, be sure to check the system clocks on both your
567 server and client machines. Internet Explorer is very picky about
568 timestamps for cookies. You can quickly sync a Debian system by
569 installing the "ntpdate" package:
571 sudo aptitude -y install ntpdate
573 And then run the following command:
577 Or, depending on your firewall configuration:
579 sudo ntpdate-debian -u
581 Note: NTP can be a little more finicky about firewalls because it uses
582 UDP vs. the more common TCP that you see with most Internet protocols.
583 Worse case, you might have to manually set the time on your development
584 box instead of using NTP.
586 Open C<root/src/books/list.tt2> and add the following lines to the
587 bottom (below the closing </table> tag):
591 <a href="[% c.uri_for('/login') %]">Login</a>
592 <a href="[% c.uri_for(c.controller.action_for('form_create')) %]">Create</a>
595 Reload your browser and you should now see a "Login" and "Create" links
596 at the bottom of the page (as mentioned earlier, you can update template
597 files without a development server reload). Click the first link
598 to return to the login page. This time you I<should> see the "You are
599 already logged in" message.
601 Finally, click the C<You can logout here> link on the C</login> page.
602 You should stay at the login page, but the message should change to "You
603 need to log in to use this application."
606 =head1 USING PASSWORD HASHES
608 In this section we increase the security of our system by converting
609 from cleartext passwords to SHA-1 password hashes that include a
610 random "salt" value to make them extremely difficult to crack with
611 dictionary and "rainbow table" attacks.
613 B<Note:> This section is optional. You can skip it and the rest of the
614 tutorial will function normally.
616 Be aware that even with the techniques shown in this section, the browser
617 still transmits the passwords in cleartext to your application. We are
618 just avoiding the I<storage> of cleartext passwords in the database by
619 using a salted SHA-1 hash. If you are concerned about cleartext passwords
620 between the browser and your application, consider using SSL/TLS, made
621 easy with the Catalyst plugin Catalyst::Plugin:RequireSSL.
624 =head2 Re-Run the DBIC::Schema Model Helper to Include DBIx::Class::EncodedColumn
626 Next, we can re-run the model helper to have it include
627 L<DBIx::Class::EncodedColumn|DBIx::Class::EncodedColumn> in all of the
628 Result Classes it generates for us. Simply use the same command we
629 saw in Chapters 3 and 4, but add C<,EncodedColumn> to the C<components>
632 $ script/myapp_create.pl model DB DBIC::Schema MyApp::Schema \
633 create=static components=TimeStamp,EncodedColumn dbi:SQLite:myapp.db \
634 on_connect_do="PRAGMA foreign_keys = ON"
636 If you then open one of the Result Classes, you will see that it
637 includes EncodedColumn in the C<load_components> line. Take a look at
638 C<lib/MyApp/Schema/Result/User.pm> since that's the main class where we
639 want to use hashed and salted passwords:
641 __PACKAGE__->load_components("InflateColumn::DateTime", "TimeStamp", "EncodedColumn");
644 =head2 Modify the "password" Column to Use EncodedColumn
646 Open the file C<lib/MyApp/Schema/Result/User.pm> and enter the following
647 text below the "# DO NOT MODIFY THIS OR ANYTHING ABOVE!" line but above
650 # Have the 'password' column use a SHA-1 hash and 10-character salt
651 # with hex encoding; Generate the 'check_password" method
652 __PACKAGE__->add_columns(
655 encode_class => 'Digest',
656 encode_args => {salt_length => 10},
657 encode_check_method => 'check_password',
661 This redefines the automatically generated definition for the password
662 fields at the top of the Result Class file to now use EncodedColumn
663 logic (C<encoded_column> is set to 1). C<encode_class> can be set to
664 either C<Digest> to use
665 L<DBIx::Class::EncodedColumn::Digest|DBIx::Class::EncodedColumn::Digest>,
666 or C<Crypt::Eksblowfish::Bcrypt> for
667 L<DBIx::Class::EncodedColumn::Crypt::Eksblowfish::Bcrypt|DBIx::Class::EncodedColumn::Crypt::Eksblowfish::Bcrypt>.
668 C<encode_args> is then used to customize the type of Digest you
669 selected. Here we only specified the size of the salt to use, but
670 we could have also modified the hashing algorithm ('SHA-256' is
671 the default) and the format to use ('base64' is the default, but
672 'hex' and 'binary' are other options). To use these, you could
673 change the C<encode_args> to something like:
675 encode_args => {algorithm => 'SHA-1',
680 =head2 Load Hashed Passwords in the Database
682 Next, let's create a quick script to load some hashed and salted passwords
683 into the C<password> column of our C<users> table. Open the file
684 C<set_hashed_passwords.pl> in your editor and enter the following text:
693 my $schema = MyApp::Schema->connect('dbi:SQLite:myapp.db');
695 my @users = $schema->resultset('User')->all;
697 foreach my $user (@users) {
698 $user->password('mypass');
702 EncodedColumn lets us simply call C<$user->check_password($password)>
703 to see if the user has supplied the correct password, or, as we show
704 above, call C<$user->update($new_password)> to update the hashed
705 password stored for this user.
707 Then run the following command:
709 $ DBIC_TRACE=1 perl -Ilib set_hashed_passwords.pl
711 We had to use the C<-Ilib> argument to tell perl to look under the
712 C<lib> directory for our C<MyApp::Schema> model.
714 The DBIC_TRACE output should show that the update worked:
716 $ DBIC_TRACE=1 perl -Ilib set_hashed_passwords.pl
717 SELECT me.id, me.username, me.password, me.email_address,
718 me.first_name, me.last_name, me.active FROM users me:
719 UPDATE users SET password = ? WHERE ( id = ? ):
720 'oXiyAcGOjowz7ISUhpIm1IrS8AxSZ9r4jNjpX9VnVeQmN6GRtRKTz', '1'
721 UPDATE users SET password = ? WHERE ( id = ? ):
722 'PmyEPrkB8EGwvaF/DvJm7LIfxoZARjv8ygFIR7pc1gEA1OfwHGNzs', '2'
723 UPDATE users SET password = ? WHERE ( id = ? ):
724 'h7CS1Fm9UCs4hjcbu2im0HumaHCJUq4Uriac+SQgdUMUfFSoOrz3c', '3'
726 But we can further confirm our actions by dumping the users table:
728 $ sqlite3 myapp.db "select * from users"
729 1|test01|38d3974fa9e9263099f7bc2574284b2f55473a9bM=fwpX2NR8|t01@na.com|Joe|Blow|1
730 2|test02|6ed8586587e53e0d7509b1cfed5df08feadc68cbMJlnPyPt0I|t02@na.com|Jane|Doe|1
731 3|test03|af929a151340c6aed4d54d7e2651795d1ad2e2f7UW8dHoGv9z|t03@na.com|No|Go|0
733 As you can see, the passwords are much harder to steal from the
734 database (not only are the hashes stored, but every hash is different
735 even though the passwords are the same because of the added "salt"
736 value). Also note that this demonstrates how to use a DBIx::Class
737 model outside of your web application -- a very useful feature in many
741 =head2 Enable Hashed and Salted Passwords
743 Edit C<lib/MyApp.pm> and update it to match the following text (the
744 only change is to the C<password_type> field):
746 # Configure SimpleDB Authentication
747 __PACKAGE__->config->{'Plugin::Authentication'} = {
750 user_model => 'DB::User',
751 password_type => 'self_check',
755 The use of C<self_check> will cause
756 Catalyst::Plugin::Authentication::Store::DBIC to call the
757 C<check_password> method we enabled on our C<password> columns.
760 =head2 Try Out the Hashed Passwords
762 The development server should restart as soon as your save the
763 C<lib/MyApp.pm> file in the previous section. You should now be able to
764 go to L<http://localhost:3000/books/list> and login as before. When
765 done, click the "logout" link on the login page (or point your browser
766 at L<http://localhost:3000/logout>).
769 =head1 USING THE SESSION FOR FLASH
771 As discussed in the previous chapter of the tutorial, C<flash> allows
772 you to set variables in a way that is very similar to C<stash>, but it
773 will remain set across multiple requests. Once the value is read, it
774 is cleared (unless reset). Although C<flash> has nothing to do with
775 authentication, it does leverage the same session plugins. Now that
776 those plugins are enabled, let's go back and update the "delete and
777 redirect with query parameters" code seen at the end of the L<Basic
778 CRUD|Catalyst::Manual::Tutorial::04_BasicCRUD> chapter of the tutorial to
779 take advantage of C<flash>.
781 First, open C<lib/MyApp/Controller/Books.pm> and modify C<sub delete>
782 to match the following (everything after the model search line of code
791 sub delete :Chained('object') :PathPart('delete') :Args(0) {
794 # Use the book object saved by 'object' and delete it along
795 # with related 'book_authors' entries
796 $c->stash->{object}->delete;
798 # Use 'flash' to save information across requests until it's read
799 $c->flash->{status_msg} = "Book deleted";
801 # Redirect the user back to the list page
802 $c->response->redirect($c->uri_for($self->action_for('list')));
805 Next, open C<root/src/wrapper.tt2> and update the TT code to pull from
806 flash vs. the C<status_msg> query parameter:
810 [%# Status and error messages %]
811 <span class="message">[% status_msg || c.flash.status_msg %]</span>
812 <span class="error">[% error_msg %]</span>
813 [%# This is where TT will stick all of your template's contents. -%]
815 </div><!-- end content -->
818 Although the sample above only shows the C<content> div, leave the
819 rest of the file intact -- the only change we made to replace
820 "|| c.request.params.status_msg" with "c.flash.status_msg" in the
821 C<< <span class="message"> >> line.
826 Authenticate using the login screen and then point your browser to
827 L<http://localhost:3000/books/url_create/Test/1/4> to create an extra
828 several books. Click the "Return to list" link and delete one of the
829 "Test" books you just added. The C<flash> mechanism should retain our
830 "Book deleted" status message across the redirect.
832 B<NOTE:> While C<flash> will save information across multiple requests,
833 I<it does get cleared the first time it is read>. In general, this is
834 exactly what you want -- the C<flash> message will get displayed on
835 the next screen where it's appropriate, but it won't "keep showing up"
836 after that first time (unless you reset it). Please refer to
837 L<Catalyst::Plugin::Session|Catalyst::Plugin::Session> for additional
841 =head2 Switch To Flash-To-Stash
843 Although the a use of flash above works well, the
844 C<status_msg || c.flash.status_msg> statement is a little ugly. A nice
845 alternative is to use the C<flash_to_stash> feature that automatically
846 copies the content of flash to stash. This makes your controller
847 and template code work regardless of where it was directly access, a
848 forward, or a redirect. To enable C<flash_to_stash>, you can either
849 set the value in C<lib/MyApp.pm> by changing the default
850 C<__PACKAGE__-E<gt>config> setting to something like:
854 # Disable deprecated behavior needed by old applications
855 disable_component_resolution_regex_fallback => 1,
856 session => { flash_to_stash => 1 },
859 B<or> add the following to C<myapp.conf>:
865 The C<__PACKAGE__-E<gt>config> option is probably preferable here
866 since it's not something you will want to change at runtime without it
867 possibly breaking some of your code.
869 Then edit C<root/src/wrapper.tt2> and change the C<status_msg> line
870 to match the following:
872 <span class="message">[% status_msg %]</span>
874 Now go to L<http://localhost:3000/books/list> in your browser. Delete
875 another of the "Test" books you added in the previous step. Flash should
876 still maintain the status message across the redirect even though you
877 are no longer explicitly accessing C<c.flash>.
882 Kennedy Clark, C<hkclark@gmail.com>
884 Please report any errors, issues or suggestions to the author. The
885 most recent version of the Catalyst Tutorial can be found at
886 L<http://dev.catalyst.perl.org/repos/Catalyst/Catalyst-Manual/5.80/trunk/lib/Catalyst/Manual/Tutorial/>.
888 Copyright 2006-2010, Kennedy Clark, under the
889 Creative Commons Attribution Share-Alike License Version 3.0
890 (L<http://creativecommons.org/licenses/by-sa/3.0/us/>).