Rework tutorial. Lots of things changed, but key items include: new content in Catal...
[catagits/Catalyst-Manual.git] / lib / Catalyst / Manual / Tutorial / Authentication.pod
d442cc9f 1=head1 NAME
3533daff 3Catalyst::Manual::Tutorial::Authentication - Catalyst Tutorial - Part 5: Authentication
d442cc9f 4
6=head1 OVERVIEW
3533daff 8This is B<Part 5 of 10> for the Catalyst tutorial.
d442cc9f 9
10L<Tutorial Overview|Catalyst::Manual::Tutorial>
12=over 4
14=item 1
18=item 2
20L<Catalyst Basics|Catalyst::Manual::Tutorial::CatalystBasics>
22=item 3
3533daff 24L<More Catalyst Basics|Catalyst::Manual::Tutorial::MoreCatalystBasics>
d442cc9f 25
26=item 4
3533daff 28L<Basic CRUD|Catalyst::Manual::Tutorial::BasicCRUD>
d442cc9f 29
30=item 5
3533daff 32B<Authentication>
d442cc9f 33
34=item 6
3533daff 36L<Authorization|Catalyst::Manual::Tutorial::Authorization>
d442cc9f 37
38=item 7
3533daff 40L<Debugging|Catalyst::Manual::Tutorial::Debugging>
d442cc9f 41
42=item 8
3533daff 44L<Testing|Catalyst::Manual::Tutorial::Testing>
d442cc9f 45
46=item 9
3533daff 48L<Advanced CRUD|Catalyst::Manual::Tutorial::AdvancedCRUD>
d442cc9f 49
3533daff 50=item 10
d442cc9f 51
3533daff 52L<Appendices|Catalyst::Manual::Tutorial::Appendices>
d442cc9f 53
3533daff 54=back
2d0526d1 55
2d0526d1 56
d442cc9f 57=head1 DESCRIPTION
3533daff 59Now that we finally have a simple yet functional application, we can
60focus on providing authentication (with authorization coming next in
d442cc9f 61Part 5).
63This part of the tutorial is divided into two main sections: 1) basic,
64cleartext authentication and 2) hash-based authentication.
66You can checkout the source code for this example from the catalyst
67subversion repository as per the instructions in
72This section explores how to add authentication logic to a Catalyst
76=head2 Add Users and Roles to the Database
78First, we add both user and role information to the database (we will
79add the role information here although it will not be used until the
80authorization section, Part 5). Create a new SQL script file by opening
81C<myapp02.sql> in your editor and insert:
83 --
84 -- Add users and roles tables, along with a many-to-many join table
85 --
86 CREATE TABLE users (
88 username TEXT,
89 password TEXT,
90 email_address TEXT,
91 first_name TEXT,
92 last_name TEXT,
93 active INTEGER
94 );
95 CREATE TABLE roles (
97 role TEXT
98 );
99 CREATE TABLE user_roles (
100 user_id INTEGER,
101 role_id INTEGER,
102 PRIMARY KEY (user_id, role_id)
103 );
104 --
105 -- Load up some initial test data
106 --
107 INSERT INTO users VALUES (1, 'test01', 'mypass', '', 'Joe', 'Blow', 1);
108 INSERT INTO users VALUES (2, 'test02', 'mypass', '', 'Jane', 'Doe', 1);
109 INSERT INTO users VALUES (3, 'test03', 'mypass', '', 'No', 'Go', 0);
110 INSERT INTO roles VALUES (1, 'user');
111 INSERT INTO roles VALUES (2, 'admin');
112 INSERT INTO user_roles VALUES (1, 1);
113 INSERT INTO user_roles VALUES (1, 2);
114 INSERT INTO user_roles VALUES (2, 1);
115 INSERT INTO user_roles VALUES (3, 1);
117Then load this into the C<myapp.db> database with the following command:
119 $ sqlite3 myapp.db < myapp02.sql
122=head2 Add User and Role Information to DBIC Schema
3533daff 124Although we could manually edit the DBIC schema information to include
125the new tables added in the previous step, let's use the C<create=static>
126option on the DBIC model helper to do most of the work for us:
d442cc9f 127
3533daff 128 $ script/ model MyAppDB DBIC::Schema MyApp::Schema::MyAppDB create=static dbi:SQLite:myapp.db
129 $ ls lib/MyApp/Schema/MyAppDB
d442cc9f 131
3533daff 132Notice how the helper has added three new table-specific result source
133files to the C<lib/MyApp/Schema/MyApp> directory. And, more
134importantly, even if there were changes to the existing result source
135files, those changes would have only been written above the C<# DO NOT
136MODIFY THIS OR ANYTHING ABOVE!> comment and your hand-editted
137enhancements would have been preserved.
d442cc9f 138
d442cc9f 139
3533daff 140Speaking of "hand-editted enhancements," we should now add
141relationship information to the three new result source files. Edit
142each of these files and add the following information between the C<#
143DO NOT MODIFY THIS OR ANYTHING ABOVE!> comment and the closing C<1;>:
d442cc9f 144
3533daff 145C<lib/MyApp/Schema/MyAppDB/>:
d442cc9f 146
d442cc9f 147 #
148 # Set relationships:
149 #
151 # has_many():
152 # args:
153 # 1) Name of relationship, DBIC will create accessor with this name
154 # 2) Name of the model class referenced by this relationship
155 # 3) Column name in *foreign* table
3533daff 156 __PACKAGE__->has_many(map_user_role => 'MyApp::Schema::MyAppDB::UserRoles', 'user_id');
d442cc9f 157
3533daff 158 # many_to_many():
159 # args:
160 # 1) Name of relationship, DBIC will create accessor with this name
161 # 2) Name of has_many() relationship this many_to_many() is shortcut for
162 # 3) Name of belongs_to() relationship in model class of has_many() above
163 # You must already have the has_many() defined to use a many_to_many().
164 __PACKAGE__->many_to_many(roles => 'map_user_role', 'role');
d442cc9f 165
3533daff 167C<lib/MyApp/Schema/MyAppDB/>:
d442cc9f 168
d442cc9f 169 #
170 # Set relationships:
171 #
173 # has_many():
174 # args:
175 # 1) Name of relationship, DBIC will create accessor with this name
176 # 2) Name of the model class referenced by this relationship
177 # 3) Column name in *foreign* table
3533daff 178 __PACKAGE__->has_many(map_user_role => 'MyApp::Schema::MyAppDB::UserRoles', 'role_id');
d442cc9f 179
3533daff 181C<lib/MyApp/Schema/MyAppDB/>:
d442cc9f 182
d442cc9f 183 #
184 # Set relationships:
185 #
187 # belongs_to():
188 # args:
189 # 1) Name of relationship, DBIC will create accessor with this name
190 # 2) Name of the model class referenced by this relationship
191 # 3) Column name in *this* table
3533daff 192 __PACKAGE__->belongs_to(user => 'MyApp::Schema::MyAppDB::Users', 'user_id');
d442cc9f 193
194 # belongs_to():
195 # args:
196 # 1) Name of relationship, DBIC will create accessor with this name
197 # 2) Name of the model class referenced by this relationship
198 # 3) Column name in *this* table
3533daff 199 __PACKAGE__->belongs_to(role => 'MyApp::Schema::MyAppDB::Roles', 'role_id');
d442cc9f 200
3533daff 201
202The code for these three sets of updates is obviously very similar to
203the edits we made to the C<Books>, C<Authors>, and C<BookAuthors>
204classes created in Part 3.
206Note that we do not need to make any change to the
207C<lib/MyApp/Schema/> schema file. It simple tells DBIC to
208load all of the result source files it finds in below the
209C<lib/MyApp/Schema/MyAppDB> directory, so it will automatically pick
210up our new table information.
d442cc9f 211
213=head2 Sanity-Check Reload of Development Server
3533daff 215We aren't ready to try out the authentication just yet; we only want
216to do a quick check to be sure our model loads correctly. Press
217C<Ctrl-C> to kill the previous server instance (if it's still running)
218and restart it:
d442cc9f 219
220 $ script/
222Look for the three new model objects in the startup debug output:
224 ...
225 .-------------------------------------------------------------------+----------.
226 | Class | Type |
227 +-------------------------------------------------------------------+----------+
228 | MyApp::Controller::Books | instance |
229 | MyApp::Controller::Root | instance |
230 | MyApp::Model::MyAppDB | instance |
231 | MyApp::Model::MyAppDB::Author | class |
3533daff 232 | MyApp::Model::MyAppDB::Books | class |
233 | MyApp::Model::MyAppDB::BookAuthors | class |
234 | MyApp::Model::MyAppDB::Roles | class |
235 | MyApp::Model::MyAppDB::Users | class |
236 | MyApp::Model::MyAppDB::UserRoles | class |
d442cc9f 237 | MyApp::View::TT | instance |
238 '-------------------------------------------------------------------+----------'
239 ...
3533daff 241Again, notice that your "result source" classes have been "re-loaded"
242by Catalyst under C<MyApp::Model>.
d442cc9f 243
245=head2 Include Authentication and Session Plugins
3533daff 247Edit C<lib/> and update it as follows (everything below
248C<StackTrace> is new):
d442cc9f 249
250 use Catalyst qw/
251 -Debug
252 ConfigLoader
253 Static::Simple
255 StackTrace
257 Authentication
d442cc9f 258
259 Session
260 Session::Store::FastMmap
261 Session::State::Cookie
262 /;
3533daff 264The C<Authentication> plugin supports Authentication while the
265C<Session> plugins are required to maintain state across multiple HTTP
6d0971ad 267
3533daff 268Note that the only required Authentication class is the main one. This
269is a change that occurred in version 0.09999_01 of the
270C<Authentication> plugin. You B<do not need> to specify a particular
271Authentication::Store or Authentication::Credential plugin. Instead,
272indicate the Store and Credential you want to use in your application
6d0971ad 273configuration (see below).
3533daff 275Note that there are several options for
278is generally a good choice if you are on Unix; try
279L<Session::Store::File|Catalyst::Plugin::Session::Store::File> if you
280are on Win32) -- consult
281L<Session::Store|Catalyst::Plugin::Session::Store> and its subclasses
282for additional information and options (for example to use a database-
283backed session store).
d442cc9f 284
286=head2 Configure Authentication
3533daff 288Although C<__PACKAGE__-E<gt>config(name =E<gt> 'value');> is still
289supported, newer Catalyst applications tend to place all configuration
290information in C<myapp.yml> and automatically load this information
291into C<MyApp-E<gt>config> using the
292L<ConfigLoader|Catalyst::Plugin::ConfigLoader> plugin. Here, we need
d442cc9f 293to load several parameters that tell
3533daff 294L<Catalyst::Plugin::Authentication|Catalyst::Plugin::Authentication>
d442cc9f 295where to locate information in your database. To do this, edit the
296C<myapp.yml> YAML and update it to match:
298 ---
299 name: MyApp
300 authentication:
6d0971ad 301 default_realm: dbic
302 realms:
303 dbic:
304 credential:
3533daff 305 # Note this first definition would be the same as setting
306 # __PACKAGE__->config->{authentication}->{realms}->{dbic}
307 # ->{credential} = 'Password' in lib/
308 # (IOW, each hash key becomes a "name:" in the YAML file).
309 #
310 # Specify that we are going to do password-based auth
311 class: Password
312 # This is the name of the field in the users table with the
313 # password stored in it
6d0971ad 314 password_field: password
3533daff 315 # We are using an unencrypted password now
316 password_type: clear
6d0971ad 317 store:
3533daff 318 # Use DBIC to retrieve username, password & role information
6d0971ad 319 class: DBIx::Class
3533daff 320 # This is the model object created by Catalyst::Model::DBIC
321 # from your schema (you created 'MyAppDB::User' but as the
322 # Catalyst startup debug messages show, it was loaded as
323 # 'MyApp::Model::MyAppDB::Users').
324 # NOTE: Omit 'MyApp::Model' here just as you would when using
325 # '$c->model("MyAppDB::Users)'
326 user_class: MyAppDB::Users
327 # This is the name of the field in your 'users' table that
328 # contains the user's name
6d0971ad 329 id_field: username
d442cc9f 330
331Inline comments in the code above explain how each field is being used.
3533daff 333B<TIP>: Although YAML uses a very simple and easy-to-ready format, it
334does require the use of a consistent level of indenting. Be sure you
335line up everything on a given 'level' with the same number of indents.
336Also, be sure B<not> to use C<tab> characters (YAML does not support
337them because they are handled inconsistently across editors).
d442cc9f 338
340=head2 Add Login and Logout Controllers
342Use the Catalyst create script to create two stub controller files:
344 $ script/ controller Login
345 $ script/ controller Logout
347B<NOTE>: You could easily use a single controller here. For example,
348you could have a C<User> controller with both C<login> and C<logout>
349actions. Remember, Catalyst is designed to be very flexible, and leaves
350such matters up to you, the designer and programmer.
352Then open C<lib/MyApp/Controller/>, locate the C<sub index :
353Private> method (this was automatically inserted by the helpers when we
354created the Login controller above), and delete this line:
356 $c->response->body('Matched MyApp::Controller::Login in Login.');
358Then update it to match:
360 =head2 index
362 Login logic
364 =cut
366 sub index : Private {
367 my ($self, $c) = @_;
369 # Get the username and password from form
370 my $username = $c->request->params->{username} || "";
371 my $password = $c->request->params->{password} || "";
373 # If the username and password values were found in form
374 if ($username && $password) {
375 # Attempt to log the user in
f632e28b 376 if ($c->authenticate({ username => $username,
377 password => $password} )) {
d442cc9f 378 # If successful, then let them use the application
379 $c->response->redirect($c->uri_for('/books/list'));
380 return;
381 } else {
382 # Set an error message
383 $c->stash->{error_msg} = "Bad username or password.";
384 }
385 }
387 # If either of above don't work out, send to the login page
388 $c->stash->{template} = 'login.tt2';
389 }
391This controller fetches the C<username> and C<password> values from the
f632e28b 392login form and attempts to authenticate the user. If successful, it
393redirects the user to the book list page. If the login fails, the user
394will stay at the login page but receive an error message. If the
395C<username> and C<password> values are not present in the form, the
396user will be taken to the empty login form.
d442cc9f 397
398Note that we could have used something like C<sub default :Private>;
399however, the use of C<default> actions is discouraged because it does
400not receive path args as with other actions. The recommended practice
401is to only use C<default> in C<MyApp::Controller::Root>.
403Another option would be to use something like
404C<sub base :Path :Args(0) {...}> (where the C<...> refers to the login
405code shown in C<sub index : Private> above). We are using C<sub base
406:Path :Args(0) {...}> here to specifically match the URL C</login>.
407C<Path> actions (aka, "literal actions") create URI matches relative to
408the namespace of the controller where they are defined. Although
409C<Path> supports arguments that allow relative and absolute paths to be
410defined, here we use an empty C<Path> definition to match on just the
411name of the controller itself. The method name, C<base>, is arbitrary.
412We make the match even more specific with the C<:Args(0)> action
413modifier -- this forces the match on I<only> C</login>, not
3533daff 416Next, update the corresponding method in
417C<lib/MyApp/Controller/> to match:
d442cc9f 418
419 =head2 index
421 Logout logic
423 =cut
425 sub index : Private {
426 my ($self, $c) = @_;
428 # Clear the user's state
429 $c->logout;
431 # Send the user to the starting point
432 $c->response->redirect($c->uri_for('/'));
433 }
435As with the login controller, be sure to delete the
436C<$c->response->body('Matched MyApp::Controller::Logout in Logout.');>
437line of the C<sub index>.
440=head2 Add a Login Form TT Template Page
442Create a login form by opening C<root/src/login.tt2> and inserting:
444 [% META title = 'Login' %]
446 <!-- Login form -->
447 <form method="post" action=" [% Catalyst.uri_for('/login') %] ">
448 <table>
449 <tr>
450 <td>Username:</td>
451 <td><input type="text" name="username" size="40" /></td>
452 </tr>
453 <tr>
454 <td>Password:</td>
455 <td><input type="password" name="password" size="40" /></td>
456 </tr>
457 <tr>
458 <td colspan="2"><input type="submit" name="submit" value="Submit" /></td>
459 </tr>
460 </table>
461 </form>
464=head2 Add Valid User Check
466We need something that provides enforcement for the authentication
467mechanism -- a I<global> mechanism that prevents users who have not
468passed authentication from reaching any pages except the login page.
469This is generally done via an C<auto> action/method (prior to Catalyst
470v5.66, this sort of thing would go in C<>, but starting in
471v5.66, the preferred location is C<lib/MyApp/Controller/>).
473Edit the existing C<lib/MyApp/Controller/> class file and insert
474the following method:
476 =head2 auto
478 Check if there is a user and, if not, forward to login page
480 =cut
482 # Note that 'auto' runs after 'begin' but before your actions and that
483 # 'auto' "chain" (all from application path to most specific class are run)
484 # See the 'Actions' section of 'Catalyst::Manual::Intro' for more info.
485 sub auto : Private {
486 my ($self, $c) = @_;
488 # Allow unauthenticated users to reach the login page. This
489 # allows anauthenticated users to reach any action in the Login
490 # controller. To lock it down to a single action, we could use:
491 # if ($c->action eq $c->controller('Login')->action_for('index'))
492 # to only allow unauthenticated access to the C<index> action we
493 # added above.
494 if ($c->controller eq $c->controller('Login')) {
495 return 1;
496 }
498 # If a user doesn't exist, force login
499 if (!$c->user_exists) {
500 # Dump a log message to the development server debug output
501 $c->log->debug('***Root::auto User not found, forwarding to /login');
502 # Redirect the user to the login page
503 $c->response->redirect($c->uri_for('/login'));
504 # Return 0 to cancel 'post-auto' processing and prevent use of application
505 return 0;
506 }
508 # User found, so return 1 to continue with processing after this 'auto'
509 return 1;
510 }
3533daff 512
513B<Note:> Catalyst provides a number of different types of actions,
514such as C<Local>, C<Regex>, C<Private> and the new C<Path>. You
515should refer to L<Catalyst::Manual::Intro|Catalyst::Manual::Intro> for
516a more detailed explanation, but the following bullet points provide a
517quick introduction:
d442cc9f 518
519=over 4
521=item *
3533daff 523The majority of application have traditionally use C<Local> actions
524for items that respond to user requests and C<Private> actions for
525those that do not directly respond to user input.
d442cc9f 526
527=item *
3533daff 529Newer Catalyst applications tend to use C<Path> actions and the
530C<Args> attribute because of their power and flexibility. You can
531specify the path to match relative to the namespace of the current
532module as an argument to C<Path>. For example C<Path('list')> in
533C<lib/MyApp/Controller/> would match on the URL
534C<http://localhost:3000/books/list> but C<Path('/list')> would
535match on C<http://localhost:3000/list>.
537=item *
539Automatic "chaining" of actions by the dispatcher is a powerful
540feature that allows multiple methods to handle a single URL. See
542for more information on chained actions.
544=item *
546There are five types of build-in C<Private> actions: C<begin>, C<end>,
d442cc9f 547C<default>, C<index>, and C<auto>.
549=item *
551With C<begin>, C<end>, C<default>, C<index> private actions, only the
552most specific action of each type will be called. For example, if you
553define a C<begin> action in your controller it will I<override> a
554C<begin> action in your application/root controller -- I<only> the
555action in your controller will be called.
557=item *
559Unlike the other actions where only a single method is called for each
560request, I<every> auto action along the chain of namespaces will be
561called. Each C<auto> action will be called I<from the application/root
562controller down through the most specific class>.
566By placing the authentication enforcement code inside the C<auto> method
567of C<lib/MyApp/Controller/> (or C<lib/>), it will be
568called for I<every> request that is received by the entire application.
571=head2 Displaying Content Only to Authenticated Users
573Let's say you want to provide some information on the login page that
574changes depending on whether the user has authenticated yet. To do
575this, open C<root/src/login.tt2> in your editor and add the following
576lines to the bottom of the file:
578 <p>
579 [%
580 # This code illustrates how certain parts of the TT
581 # template will only be shown to users who have logged in
582 %]
583 [% IF Catalyst.user_exists %]
584 Please Note: You are already logged in as '[% Catalyst.user.username %]'.
585 You can <a href="[% Catalyst.uri_for('/logout') %]">logout</a> here.
586 [% ELSE %]
587 You need to log in to use this application.
588 [% END %]
589 [%#
590 Note that this whole block is a comment because the "#" appears
591 immediate after the "[%" (with no spaces in between). Although it
592 can be a handy way to temporarily "comment out" a whole block of
593 TT code, it's probably a little too subtle for use in "normal"
595 %]
3533daff 596 </p>
d442cc9f 597
598Although most of the code is comments, the middle few lines provide a
599"you are already logged in" reminder if the user returns to the login
600page after they have already authenticated. For users who have not yet
601authenticated, a "You need to log in..." message is displayed (note the
602use of an IF-THEN-ELSE construct in TT).
605=head2 Try Out Authentication
607Press C<Ctrl-C> to kill the previous server instance (if it's still
608running) and restart it:
610 $ script/
612B<IMPORTANT NOTE>: If you happen to be using Internet Explorer, you may
613need to use the command C<script/ -k> to enable the
614keepalive feature in the development server. Otherwise, the HTTP
615redirect on successful login may not work correctly with IE (it seems to
616work without -k if you are running the web browser and development
617server on the same machine). If you are using browser a browser other
618than IE, it should work either way. If you want to make keepalive the
619default, you can edit C<script/> and change the
620initialization value for C<$keepalive> to C<1>. (You will need to do
621this every time you create a new Catalyst application or rebuild the
622C<> script.)
624Now trying going to L<http://localhost:3000/books/list> and you should
625be redirected to the login page, hitting Shift+Reload if necessary (the
626"You are already logged in" message should I<not> appear -- if it does,
627click the C<logout> button and try again). Note the C<***Root::auto User
628not found...> debug message in the development server output. Enter
629username C<test01> and password C<mypass>, and you should be taken to
630the Book List page.
632Open C<root/src/books/list.tt2> and add the following lines to the
3533daff 633bottom (below the closing </table> tag):
d442cc9f 634
635 <p>
636 <a href="[% Catalyst.uri_for('/login') %]">Login</a>
637 <a href="[% Catalyst.uri_for('form_create') %]">Create</a>
638 </p>
640Reload your browser and you should now see a "Login" and "Create" links
641at the bottom of the page (as mentioned earlier, you can update template
642files without reloading the development server). Click the first link
643to return to the login page. This time you I<should> see the "You are
644already logged in" message.
646Finally, click the C<You can logout here> link on the C</login> page.
647You should stay at the login page, but the message should change to "You
648need to log in to use this application."
653In this section we increase the security of our system by converting
654from cleartext passwords to SHA-1 password hashes.
656B<Note:> This section is optional. You can skip it and the rest of the
657tutorial will function normally.
659Note that even with the techniques shown in this section, the browser
660still transmits the passwords in cleartext to your application. We are
661just avoiding the I<storage> of cleartext passwords in the database by
662using a SHA-1 hash. If you are concerned about cleartext passwords
663between the browser and your application, consider using SSL/TLS, made
664easy with the Catalyst plugin Catalyst::Plugin:RequireSSL.
667=head2 Get a SHA-1 Hash for the Password
669Catalyst uses the C<Digest> module to support a variety of hashing
670algorithms. Here we will use SHA-1 (SHA = Secure Hash Algorithm).
671First, we should compute the SHA-1 hash for the "mypass" password we are
672using. The following command-line Perl script provides a "quick and
673dirty" way to do this:
675 $ perl -MDigest::SHA -e 'print Digest::SHA::sha1_hex("mypass"), "\n"'
676 e727d1464ae12436e899a726da5b2f11d8381b26
677 $
679B<Note:> You should probably modify this code for production use to
680not read the password from the command line. By having the script
681prompt for the cleartext password, it avoids having the password linger
682in forms such as your C<.bash_history> files (assuming you are using
683BASH as your shell). An example of such a script can be found in
684Appendix 3.
687=head2 Switch to SHA-1 Password Hashes in the Database
689Next, we need to change the C<password> column of our C<users> table to
690store this hash value vs. the existing cleartext password. Open
691C<myapp03.sql> in your editor and enter:
693 --
694 -- Convert passwords to SHA-1 hashes
695 --
696 UPDATE users SET password = 'e727d1464ae12436e899a726da5b2f11d8381b26' WHERE id = 1;
697 UPDATE users SET password = 'e727d1464ae12436e899a726da5b2f11d8381b26' WHERE id = 2;
698 UPDATE users SET password = 'e727d1464ae12436e899a726da5b2f11d8381b26' WHERE id = 3;
700Then use the following command to update the SQLite database:
702 $ sqlite3 myapp.db < myapp03.sql
704B<Note:> We are using SHA-1 hashes here, but many other hashing
705algorithms are supported. See C<Digest> for more information.
708=head2 Enable SHA-1 Hash Passwords in
711Edit C<myapp.yml> and update it to match (the C<password_type> and
712C<password_hash_type> are new, everything else is the same):
714 ---
715 name: MyApp
716 authentication:
3533daff 717 default_realm: dbic
718 realms:
719 dbic:
720 credential:
721 # Note this first definition would be the same as setting
722 # __PACKAGE__->config->{authentication}->{realms}->{dbic}
723 # ->{credential} = 'Password' in lib/
724 # (IOW, each hash key becomes a "name:" in the YAML file).
725 #
726 # Specify that we are going to do password-based auth
727 class: Password
728 # This is the name of the field in the users table with the
729 # password stored in it
730 password_field: password
731 # Switch to more secure hashed passwords
732 password_type: hashed
733 # Use the SHA-1 hashing algorithm
734 password_hash_type: SHA-1
735 store:
736 # Use DBIC to retrieve username, password & role information
737 class: DBIx::Class
738 # This is the model object created by Catalyst::Model::DBIC
739 # from your schema (you created 'MyAppDB::User' but as the
740 # Catalyst startup debug messages show, it was loaded as
741 # 'MyApp::Model::MyAppDB::Users').
742 # NOTE: Omit 'MyApp::Model' here just as you would when using
743 # '$c->model("MyAppDB::Users)'
744 user_class: MyAppDB::Users
745 # This is the name of the field in your 'users' table that
746 # contains the user's name
747 id_field: username
d442cc9f 748
750=head2 Try Out the Hashed Passwords
752Press C<Ctrl-C> to kill the previous server instance (if it's still
753running) and restart it:
755 $ script/
757You should now be able to go to L<http://localhost:3000/books/list> and
758login as before. When done, click the "Logout" link on the login page
759(or point your browser at L<http://localhost:3000/logout>).
d442cc9f 761
764As discussed in Part 3 of the tutorial, C<flash> allows you to set
765variables in a way that is very similar to C<stash>, but it will
766remain set across multiple requests. Once the value is read, it
767is cleared (unless reset). Although C<flash> has nothing to do with
768authentication, it does leverage the same session plugins. Now that
769those plugins are enabled, let's go back and improve the "delete
770and redirect with query parameters" code seen at the end of the
771L<Basic CRUD|Catalyst::Manual::Tutorial::BasicCRUD> part of the
774First, open C<lib/MyApp/Controller/> and modify C<sub delete>
3533daff 775to match the following (everything after the model search line of code
776has changed):
d442cc9f 777
778 =head2 delete
780 Delete a book
782 =cut
784 sub delete : Local {
785 # $id = primary key of book to delete
786 my ($self, $c, $id) = @_;
788 # Search for the book and then delete it
3533daff 789 $c->model('MyAppDB::Books')->search({id => $id})->delete_all;
d442cc9f 790
791 # Use 'flash' to save information across requests until it's read
792 $c->flash->{status_msg} = "Book deleted";
3533daff 794 # Redirect the user back to the list page
d442cc9f 795 $c->response->redirect($c->uri_for('/books/list'));
796 }
798Next, open C<root/lib/site/layout> and update the TT code to pull from
799flash vs. the C<status_msg> query parameter:
801 <div id="header">[% PROCESS site/header %]</div>
803 <div id="content">
804 <span class="message">[% status_msg || Catalyst.flash.status_msg %]</span>
805 <span class="error">[% error_msg %]</span>
806 [% content %]
807 </div>
809 <div id="footer">[% PROCESS site/footer %]</div>
812=head2 Try Out Flash
814Restart the development server and point your browser to
3533daff 815L<http://localhost:3000/books/url_create/Test/1/4> to create an extra
816several books. Click the "Return to list" link and delete one of the
817"Test" books you just added. The C<flash> mechanism should retain our
818"Book deleted" status message across the redirect.
d442cc9f 819
820B<NOTE:> While C<flash> will save information across multiple requests,
821I<it does get cleared the first time it is read>. In general, this is
822exactly what you want -- the C<flash> message will get displayed on
823the next screen where it's appropriate, but it won't "keep showing up"
824after that first time (unless you reset it). Please refer to
825L<Catalyst::Plugin::Session|Catalyst::Plugin::Session> for additional
3533daff 828=head2 Switch To Flash-To-Stash
830Although the a use of flash above is certainly an improvement over the
831C<status_msg> we employed in Part 4 of the tutorial, the C<status_msg
832|| Catalyst.flash.status_msg> statement is a little ugly. A nice
833alternative is to use the C<flash_to_stash> feature that automatically
834copies the content of flash to stash. This makes your code controller
835and template code work regardless of where it was directly access, a
836forward, or a redirect. To enable C<flash_to_stash>, you can either
837set the value in C<lib/> by changing the default
838C<__PACKAGE__-E<gt>config> setting to something like:
840 __PACKAGE__->config(
841 name => 'MyApp',
842 session => {flash_to_stash => 1}
843 );
845B<or> add the following to C<myapp.yml>:
847 session:
848 flash_to_stash: 1
850The C<__PACKAGE__-E<gt>config> option is probably preferable here
851since it's not something you will want to change at runtime without it
852possibly breaking some of your code.
854Then edit C<root/lib/site/layout> and change the C<status_msg> line
855to look like the following:
857 <span class="message">[% status_msg %]</span>
859Restart the development server and go to
860L<http://localhost:3000/books/list> in your browser. Delete another
861of the "Test" books you added in the previous step. Flash should still
862maintain the status message across the redirect even though you are no
863longer explicitly accessing C<Catalyst.flash>.
d442cc9f 865
866=head1 AUTHOR
868Kennedy Clark, C<>
870Please report any errors, issues or suggestions to the author. The
871most recent version of the Catalyst Tutorial can be found at
d712b826 872L<>.
d442cc9f 873
874Copyright 2006, Kennedy Clark, under Creative Commons License