3 Catalyst::Manual::Tutorial::Intro - Catalyst Tutorial - Part 1: Introduction
8 This is B<Part 1 of 10> for the Catalyst tutorial.
10 L<Tutorial Overview|Catalyst::Manual::Tutorial>
20 L<Catalyst Basics|Catalyst::Manual::Tutorial::CatalystBasics>
24 L<More Catalyst Basics|Catalyst::Manual::Tutorial::MoreCatalystBasics>
28 L<Basic CRUD|Catalyst::Manual::Tutorial::BasicCRUD>
32 L<Authentication|Catalyst::Manual::Tutorial::Authentication>
36 L<Authorization|Catalyst::Manual::Tutorial::Authorization>
40 L<Debugging|Catalyst::Manual::Tutorial::Debugging>
44 L<Testing|Catalyst::Manual::Tutorial::Testing>
48 L<Advanced CRUD|Catalyst::Manual::Tutorial::AdvancedCRUD>
52 L<Appendices|Catalyst::Manual::Tutorial::Appendices>
59 This tutorial provides a multi-part introduction to the Catalyst web
60 framework. It seeks to provide a rapid overview of many of its most
61 commonly used features. The focus is on the real-world best practices
62 required in the construction of nearly all Catalyst applications.
64 Although the primary target of the tutorial is users new to the Catalyst
65 framework, experienced users may wish to review specific sections (for
66 example, how to use DBIC for their model classes, how to add
67 authentication and authorization to an existing application, or form
70 You can obtain the code for all the tutorial examples from the
71 catalyst subversion repository by issuing the command:
73 svn co http://dev.catalyst.perl.org/repos/Catalyst/trunk/examples/Tutorial/ CatalystTutorial
75 This will download the most recent tarball for each part of the
76 tutorial into the CatalystTutorial directory on your machine.
78 B<These reference implementations are provided so that when you follow
79 the tutorial, you can use the code from the subversion repository to
80 ensure that your system is set up correctly, and that you have not
81 inadvertently made any typographic errors, or accidentally skipped
82 part of the tutorial.>
84 B<NOTE: You can use any Perl-supported OS and environment to run
85 Catalyst.> It should make little or no difference to Catalyst's
86 operation, B<but this tutorial has been written using the Debian 5
87 live CD> because that represents a quick and easy for most people to
88 try out Catalyst with virtually zero setup time and hassles. Also,
89 the tutorial has been tested to work correctly with the versions of
90 Catalyst and all the supporting modules in Debian 5 (see "VERSIONS
91 AND CONVENTIONS USED IN THIS TUTORIAL" below for the specific versions
92 for some of the key modules), so B<if you think you might be running
93 into an issue related to versions> (for example, a module changed its
94 behavior in a newer version or a bug was introduced), B<it might be
95 worth giving Debian 5 a try>. See the "CATALYST INSTALLATION"
96 section below for more information.
98 If you're reading this manual online, you can download the example
99 program and all the necessary dependencies to your local machine by
100 installing the C<Task::Catalyst::Tutorial> distribution from CPAN:
102 cpan Task::Catalyst::Tutorial
104 This will also test to make sure the dependencies are working. If you
105 have trouble installing these, please ask for help on the #catalyst
106 IRC channel, or the Catalyst mailing list.
108 Subjects covered by the tutorial include:
114 A simple application that lists and adds books.
118 The use of L<DBIx::Class|DBIx::Class> (DBIC) for the model (including
119 some of the more advanced techniques you will probably want to use in
124 How to write CRUD (Create, Read, Update, and Delete) operations in
129 Authentication ("auth").
133 Role-based authorization ("authz").
137 Attempts to provide an example showing current (5.7XXX) Catalyst
138 practices. For example, the use of
139 L<Catalyst::Action::RenderView|Catalyst::Action::RenderView>,
140 DBIC, L<Catalyst::Plugin::ConfigLoader|Catalyst::Plugin::ConfigLoader>
141 with C<myapp.conf>, the use of C<lib/MyApp/Controller/Root.pm>
142 vs. C<lib/MyApp.pm>, etc.
146 The use of Template Toolkit (TT).
150 Useful techniques for troubleshooting and debugging Catalyst
155 The use of SQLite as a database (with code also provided for MySQL and
160 The use of L<HTML::FormFu|HTML::FormFu> for automated form processing
165 This tutorial makes the learning process its main priority. For
166 example, the level of comments in the code found here would likely be
167 considered excessive in a "normal project." Because of their contextual
168 value, this tutorial will generally favor inline comments over a
169 separate discussion in the text. It also deliberately tries to
170 demonstrate multiple approaches to various features (in general, you
171 should try to be as consistent as possible with your own production
174 Furthermore, this tutorial tries to minimize the number of controllers,
175 models, TT templates, and database tables. Although this does result in
176 things being a bit contrived at times, the concepts should be applicable
177 to more complex environments. More complete and complicated example
178 applications can be found in the C<examples> area of the Catalyst
179 Subversion repository at
180 L<http://dev.catalyst.perl.org/repos/Catalyst/trunk/examples/>.
183 =head1 VERSIONS AND CONVENTIONS USED IN THIS TUTORIAL
185 This tutorial was built using the following resources. Please note that
186 you may need to make adjustments for different environments and
201 Catalyst::Devel v1.08
211 The plugins used in this tutorial all have sufficiently stable APIs that
212 you shouldn't need to worry about versions. However, there could be
213 cases where the tutorial is affected by what version of plugins you
214 use. This tutorial has been tested against the following set of plugins:
220 Catalyst::Plugin::Authentication -- v0.10006
224 Catalyst::Plugin::Authorization::Roles -- v0.05
228 Catalyst::Plugin::ConfigLoader -- v0.20
232 Catalyst::Plugin::Session -- v0.19
236 Catalyst::Plugin::Session::State::Cookie -- v0.09
240 Catalyst::Plugin::Session::Store::FastMmap -- v0.05
244 Catalyst::Plugin::StackTrace -- v0.08
248 Catalyst::Plugin::Static::Simple -- v0.20
254 B<NOTE:> You can check the versions you have installed with the
257 perl -ME<lt>mod_nameE<gt> -e '"print $E<lt>mod_nameE<gt>::VERSION\n"'
260 perl -MCatalyst::Plugin::StackTrace -e 'print "$Catalyst::Plugin::StackTrace::VERSION\n"'
262 Since the web browser is being used on the same box where Perl and the
263 Catalyst development server is running, the URL of
264 C<http://localhost:3000> will be used (the Catalyst development server
265 defaults to port 3000). If you are running Perl on a different box than
266 where your web browser is located (or using a different port number via
267 the C<-p> I<port_number> option to the development server), then you
268 will need to update the URL you use accordingly.
272 Depending on the web browser you are using, you might need to hit
273 C<Shift+Reload> or C<Ctrl+Reload> to pull a fresh page when testing
274 your application at various points (see
275 L<http://en.wikipedia.org/wiki/Bypass_your_cache> for a comprehensive
276 list of options for each browser). Also, the C<-k> keepalive option
277 to the development server can be necessary with some browsers
278 (especially Internet Explorer).
283 =head1 CATALYST INSTALLATION
285 Although Catalyst installation has been a challenge in the past, the
286 good news is that there are a growing number of options to eliminate
287 (or at least dramatically simplify) this concern. Although a
288 compelling strength of Catalyst is that it makes use of many of the
289 modules in the vast repository that is CPAN, this can complicate the
290 installation process if you approach it in the wrong way. Consider
291 the following suggestions on the most common ways to get started with
292 a Catalyst development environment:
300 The Debian 5 live CD represents a great way for newcomers to
301 experiment with Catalyst. As a "live CD," you can simple boot from
302 the CD, run a few commands, and in a matter of minutes you should have
303 a fully function environment in which do this tutorial. B<The tutorial
304 was fully tested to work under Debian 5. Although it SHOULD work
305 under any Catalyst installation method you might choose, it can be
306 hard to guarantee this.>
312 Download one of the ISO files from
313 L<http://cdimage.debian.org/cdimage/release/current-live/i386/iso-cd/>.
314 You can pick any one of the live CD variations will work, but
315 you may wish to consider the following points:
321 "C<debian-live-500-i386-rescue.iso>" is probably the best all-around
322 option for most people because it includes many extra tools such as
323 the GCC compiler, therefore saving RAM (every package you need to
324 install when running from live CD consumes memory because RAM disk is
325 being used in lieu of real disk space). When initially booting under
326 this image, you may see some cryptic warning messages having to do
327 with various diagnostic tools it tries to load or enable, but you
328 should be able to safely ignore these.
332 "C<debian-live-500-i386-standard.iso>" is a great option because of
333 its compact size, but you will probably need approximately 1 GB of RAM
334 in the computer where you will run the tutorial. Because the
335 "standard" live CD comes with with a minimal set of tools, we will
336 have to install extra packages (such as the GCC compiler), all of
337 which will require RAM when running from a live CD.
341 The other ISO images include different flavors of X-Windows desktop
342 managers. You can select one of these if you don't mind the larger
343 download size and prefer a graphical environment. Be aware that these
344 disks do not come with the extra tools found on the "rescue" image, so
345 you will need adequate RAM to be able to install them just as you
346 would under the "standard" image. B<Use one of the "graphical" ISO
347 images if you want a graphical web browser on the same machine as
348 where you will run the tutorial.> (If you are using one of the non-
349 graphical images discussed above, you can still use a graphical web
350 browser from another machine and point it to your Catalyst development
361 Select "C<Live>" from the initial boot menu.
365 Once the system has booted to a "C<user@debian:~$>" prompt, enter the
366 following command to add the more current "unstable" package
369 sudo vi /etc/apt/sources.list
371 Add the following line to the bottom of this file:
373 deb http://ftp.us.debian.org/debian/ unstable main
375 If you are not familiar with VI, you can move to the bottom of this
376 file and press the "o" key to insert a new line and type the line
377 above. Then press the "Esc" key followed by a colon (":"), the
378 letters "wq" and then the "Enter" key. The rest of the tutorial will
379 assume that you know how to use some editor that is available from the
380 Linux command-line environment.
387 sudo aptitude -y install sqlite3 libdbd-sqlite3-perl libcatalyst-perl \
388 libcatalyst-modules-perl libconfig-general-perl libsql-translator-perl \
389 libdatetime-perl libdatetime-format-mysql-perl libio-all-perl \
390 libperl6-junction-perl
392 Let it install (normally about a 30-second operaton) and you are
395 If you are using an image other than the "rescue" ISO, you will also need
396 to run the following command to install additional packages:
398 sudo aptitude -y install gcc make libc6-dev
400 If you are running from the Live CD, you probably also want to free up
401 some RAM disk space with the following:
405 NOTE: While the instructions above mention the Live CD because that
406 makes it easy for people new to Linux, you can obviously pick a
407 different Debian ISO image and install it to your hard drive.
408 Although there are many different ways to download and install Debian,
409 the "netinst" ISO image (such as "C<debian-500-i386-netinst.iso>"
410 represents a great option because it keeps your initial download small
411 (but still let's you install anything you want "over the network").
413 Here are some tips if you are running from a live CD and are running
414 out of disk space (which really means you are running out of RAM):
420 Always run "C<aptitude clean>" after you install new packages to
421 delete the original .deb files (the files installed B<by> the .deb
422 package B<will> remain available, just the .deb package itself is
427 If you are installing modules from CPAN, you can free up some space
428 with "C<rm -rf /root/.cpan/*>".
432 If necessary, you can remove the cached package information with the
433 command "C<rm -f /var/lib/apt/lists/*>". You can later pull this
434 information again via the command "C<aptitude update>".
438 You can save a small amount of space by commenting out the lines in
439 C</etc/apt/sources.list> that reference "deb-src" and
440 "security.debian.org". If you have already done an "C<aptitude
441 update>" with these repositories enabled, you can use the tip in the
442 previous bullet to free the space up (and then do another "C<aptitude
447 Although you can free up space by removing packages you installed
448 since you last booted (check out "C<aptitude remove _pkg_name>"),
449 don't bother trying to remove packages already available at the time
450 of boot. Instead of freeing up space, it will actual I<consume> some
451 space. (The live CD uses these "burn in" packages right from the CD
452 disk vs. first loading them on the virtual RAM disk. However, if you
453 remove them, the system has to update various files, something that
454 I<does> consume some space on the virtual RAM disk.)
464 Ubuntu is an extremely popular offshoot of Debian. It provides
465 cutting edge versions of many common tools, application and libraries
466 in an easy-to-run live CD configuration (and because a single download
467 option can be used for both live CD and install-to-disk usage, it
468 keeps your download options nice and simple). As with Debian 5, you
469 should be able to generate a fully function Catalyst environment in a
470 matter of minutes. Here are quick instructions on how to use Ubuntu
471 to prepare for the tutorial:
477 Download the Ubuntu Desktop edition and boot from the CD and/or image
478 file, select your language, and then "Try Ubuntu without any changes
483 Open a terminal session (click "Applications" in the upper-left
484 corner, then "Accessories," then "Terminal").
488 Add the 'universe' repositories:
490 sudo gedit /etc/apt/sources.list
492 And remove the comments from the lines under the comments about the
493 'universe' repositories.
500 sudo aptitude install libdbd-sqlite3-perl libcatalyst-perl libcatalyst-modules-perl libconfig-general-perl
502 Accept all of the dependencies. Done.
504 If you are running from the Live CD, you probably also want to free up
505 some disk space with the following:
509 NOTE: While the instructions above mention the live CD because that
510 makes it easy for people new to Linux, you can obviously also use one
511 of the options to install Ubuntu on your drive.
517 Matt Trout's C<cat-install>
519 Available at L<http://www.shadowcatsystems.co.uk/static/cat-install>,
520 C<cat-install> can be a fairly painless way to get Catalyst up and
521 running. Just download the script from the link above and type C<perl
522 cat-install>. Depending on the speed of your Internet connection and
523 your computer, it will probably take 30 to 60 minutes to install because
524 it downloads, makes, compiles, and tests every module. But this is an
525 excellent way to automate the installation of all the latest modules
526 used by Catalyst from CPAN.
539 The 2008 Advent Day 4 entry has more information on using OpenBSD
540 packages to quickly build a system:
541 L<http://www.catalystframework.org/calendar/2008/4>.
545 NetBSD Package Collection on Solaris
547 The 2008 Advent Day 15 entry has more information on using C<pkgsrc> and
548 NetBSD packages on Solaris:
549 L<http://www.catalystframework.org/calendar/2008/15>.
555 You can get more information at
556 L<http://www.catalystframework.org/calendar/2008/7>
557 or L<Perl::Dist::CatInABox|Perl::Dist::CatInABox>.
561 Frank Speiser's Amazon EC2 Catalyst SDK
563 There are currently two flavors of publicly available Amazon Machine
564 Images (AMI) that include all the elements you'd need to begin
565 developing in a fully functional Catalyst environment within minutes.
566 See L<Catalyst::Manual::Installation|Catalyst::Manual::Installation>
573 For additional information and recommendations on Catalyst installation,
575 L<Catalyst::Manual::Installation|Catalyst::Manual::Installation>.
580 This tutorial will primarily focus on SQLite because of its simplicity
581 of installation and use; however, modifications in the script required
582 to support MySQL and PostgreSQL will be presented in Appendix.
584 B<Note:> One of the advantages of the MVC design patterns is that
585 applications become much more database independent. As such, you will
586 notice that only the C<.sql> files used to initialize the database
587 change between database systems: the Catalyst code generally remains the
591 =head1 WHERE TO GET WORKING CODE
593 Each part of the tutorial has complete code available as a tarball in
594 the main Catalyst Subversion repository (see the note at the beginning
595 of each part for the appropriate svn command to use).
597 B<NOTE:> You can run the test cases for the final code through Part 8
598 with the following commands:
600 sudo cpan Catalyst::Model::DBIC::Schema Time::Warp DBICx::TestDatabase \
601 DBIx::Class::DynamicDefault DBIx::Class::TimeStamp
602 wget http://dev.catalyst.perl.org/repos/Catalyst/trunk/examples/Tutorial/MyApp_Part8.tgz
603 tar zxvf MyApp_Part8.tgz
605 CATALYST_DEBUG=0 prove --lib lib t
607 If you wish to include the L<HTML::FormFu|HTML::FormFu> section in
608 your tests, substitute C<MyApp_Part9_FormFu.tgz> for
609 C<MyApp_Part8.tgz> in the URL above. However, you will also need to
610 run the following additional commands:
612 sudo aptitude -y install libhtml-formfu-perl libmoose-perl \
613 libregexp-assemble-perl libhtml-formfu-model-dbic-perl
615 sudo cpan Catalyst::Component::InstancePerContext Catalyst::Controller::HTML::FormFu
617 You can also fire up the application under the development server that is conveniently
618 built in to Catalyst. Just issue this command from the C<MyApp> directory where you
619 ran the test suite above:
621 script/myapp_server.pl
623 And the application will start. You can try out the application by
624 pulling up C<http://localhost:3000> in your web browser (as mentioned
625 earlier, change C<localhost> to a different IP address or DNS name if
626 you are running your web browser and your Catalyst development on
627 different boxes). We will obviously see more about how to use the
628 application as we go through the remaining parts of the tutorial, but
629 for now you can log in using the username "test01" and a password of
635 Kennedy Clark, C<hkclark@gmail.com>
637 Please report any errors, issues or suggestions to the author. The
638 most recent version of the Catalyst Tutorial can be found at
639 L<http://dev.catalyst.perl.org/repos/Catalyst/Catalyst-Manual/5.70/trunk/lib/Catalyst/Manual/Tutorial/>.
641 Copyright 2006-2008, Kennedy Clark, under Creative Commons License
642 (L<http://creativecommons.org/licenses/by-sa/3.0/us/>).