3 Catalyst::Manual::Tutorial::01_Intro - Catalyst Tutorial - Chapter 1: Introduction
8 This is B<Chapter 1 of 10> for the Catalyst tutorial.
10 L<Tutorial Overview|Catalyst::Manual::Tutorial>
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>
32 L<Authentication|Catalyst::Manual::Tutorial::05_Authentication>
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 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 chapter 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 way 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 (5.8XXX) 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 v1.10
209 Template Toolkit v2.20
215 The plugins used in this tutorial all have sufficiently stable APIs that
216 you shouldn't need to worry about versions. However, there could be
217 cases where the tutorial is affected by what version of plugins you
218 use. This tutorial has been tested against the following set of plugins:
224 Catalyst::Plugin::Authentication -- v0.10011
228 Catalyst::Plugin::Authorization::Roles -- v0.07
232 Catalyst::Plugin::ConfigLoader -- v0.22
236 Catalyst::Plugin::Session -- v0.20
240 Catalyst::Plugin::Session::State::Cookie -- v0.10
244 Catalyst::Plugin::Session::Store::FastMmap -- v0.07
248 Catalyst::Plugin::StackTrace -- v0.09
252 Catalyst::Plugin::Static::Simple -- v0.21
258 B<NOTE:> You can check the versions you have installed with the
261 perl -M<_mod_name_> -e '"print $<_mod_name_>::VERSION\n"'
264 perl -MCatalyst::Plugin::StackTrace -e 'print "$Catalyst::Plugin::StackTrace::VERSION\n"'
266 Since the web browser is being used on the same box where Perl and the
267 Catalyst development server is running, the URL of
268 C<http://localhost:3000> will be used (the Catalyst development server
269 defaults to port 3000). If you are running Perl on a different box than
270 where your web browser is located (or using a different port number via
271 the C<-p> I<port_number> option to the development server), then you
272 will need to update the URL you use accordingly.
276 Depending on the web browser you are using, you might need to hit
277 C<Shift+Reload> or C<Ctrl+Reload> to pull a fresh page when testing
278 your application at various points (see
279 L<http://en.wikipedia.org/wiki/Bypass_your_cache> for a comprehensive
280 list of options for each browser). Also, the C<-k> keepalive option
281 to the development server can be necessary with some browsers
282 (especially Internet Explorer).
287 =head1 CATALYST INSTALLATION
289 Although Catalyst installation has been a challenge in the past, the
290 good news is that there are a growing number of options to eliminate
291 (or at least dramatically simplify) this concern. Although a
292 compelling strength of Catalyst is that it makes use of many of the
293 modules in the vast repository that is CPAN, this can complicate the
294 installation process if you approach it in the wrong way. Consider
295 the following suggestions on the most common ways to get started with
296 a Catalyst development environment:
304 The Debian 5 live CD represents a great way for newcomers to
305 experiment with Catalyst. As a "live CD," you can simple boot from
306 the CD, run a few commands, and in a matter of minutes you should have
307 a fully function environment in which do this tutorial. B<The tutorial
308 was fully tested to work under Debian 5. Although it SHOULD work
309 under any Catalyst installation method you might choose, it can be
310 hard to guarantee this.>
316 Download one of the ISO files from
317 L<http://cdimage.debian.org/cdimage/release/current-live/i386/iso-cd/>.
318 You can pick any one of the live CD variations will work, but
319 you may wish to consider the following points:
325 "C<debian-live-500-i386-rescue.iso>" is probably the best all-around
326 option for most people because it includes many extra tools such as
327 the GCC compiler, therefore saving RAM (every package you need to
328 install when running from live CD consumes memory because RAM disk is
329 being used in lieu of real disk space). When initially booting under
330 this image, you may see some cryptic warning messages having to do
331 with various diagnostic tools it tries to load or enable, but you
332 should be able to safely ignore these.
336 "C<debian-live-500-i386-standard.iso>" is a great option because of
337 its compact size, but you will probably need approximately 1 GB of RAM
338 in the computer where you will run the tutorial. Because the
339 "standard" live CD comes with with a minimal set of tools, we will
340 have to install extra packages (such as the GCC compiler), all of
341 which will require RAM when running from a live CD.
345 The other ISO images include different flavors of X-Windows desktop
346 managers. You can select one of these if you don't mind the larger
347 download size and prefer a graphical environment. Be aware that these
348 disks do not come with the extra tools found on the "rescue" image, so
349 you will need adequate RAM to be able to install them just as you
350 would under the "standard" image. B<Use one of the "graphical" ISO
351 images if you want a graphical web browser on the same machine as
352 where you will run the tutorial.> (If you are using one of the non-
353 graphical images discussed above, you can still use a graphical web
354 browser from another machine and point it to your Catalyst development
365 Select "C<Live>" from the initial boot menu.
369 Once the system has booted to a "C<user@debian:~$>" prompt, enter the
370 following command to add the more current "unstable" package
373 sudo vi /etc/apt/sources.list
375 Add the following line to the bottom of this file:
377 deb http://ftp.us.debian.org/debian/ unstable main
379 If you are not familiar with VI, you can move to the bottom of this
380 file and press the "o" key to insert a new line and type the line
381 above. Then press the "Esc" key followed by a colon (":"), the
382 letters "wq" and then the "Enter" key. The rest of the tutorial will
383 assume that you know how to use some editor that is available from the
384 Linux command-line environment.
391 sudo aptitude -y install sqlite3 libdbd-sqlite3-perl libcatalyst-perl \
392 libcatalyst-modules-perl libconfig-general-perl libsql-translator-perl \
393 libdatetime-perl libdatetime-format-mysql-perl libio-all-perl \
394 libperl6-junction-perl libmoosex-emulate-class-accessor-fast-perl \
395 libdbix-class-timestamp-perl
397 Let it install (normally about a 30-second operaton) and you are done.
398 (Note the '\' above. Depending on your environment, you might be able
399 to cut and paste the text as shown or need to remove the '\'
400 characters to that the command is all on a single line.)
402 If you are using an image other than the "rescue" ISO, you will also need
403 to run the following command to install additional packages:
405 sudo aptitude -y install gcc make libc6-dev
407 If you are running from the Live CD, you probably also want to free up
408 some RAM disk space with the following:
412 NOTE: While the instructions above mention the Live CD because that
413 makes it easy for people new to Linux, you can obviously pick a
414 different Debian ISO image and install it to your hard drive.
415 Although there are many different ways to download and install Debian,
416 the "netinst" ISO image (such as "C<debian-500-i386-netinst.iso>"
417 represents a great option because it keeps your initial download small
418 (but still let's you install anything you want "over the network").
420 Here are some tips if you are running from a live CD and are running
421 out of disk space (which really means you are running out of RAM):
427 Always run "C<aptitude clean>" after you install new packages to
428 delete the original .deb files (the files installed B<by> the .deb
429 package B<will> remain available, just the .deb package itself is
434 If you are installing modules from CPAN, you can free up some space
435 with "C<rm -rf /root/.cpan/*>".
439 If necessary, you can remove the cached package information with the
440 command "C<rm -f /var/lib/apt/lists/*>". You can later pull this
441 information again via the command "C<aptitude update>".
445 You can save a small amount of space by commenting out the lines in
446 C</etc/apt/sources.list> that reference "deb-src" and
447 "security.debian.org". If you have already done an "C<aptitude
448 update>" with these repositories enabled, you can use the tip in the
449 previous bullet to free the space up (and then do another "C<aptitude
454 Although you can free up space by removing packages you installed
455 since you last booted (check out "C<aptitude remove _pkg_name>"),
456 don't bother trying to remove packages already available at the time
457 of boot. Instead of freeing up space, it will actual I<consume> some
458 space. (The live CD uses these "burn in" packages right from the CD
459 disk vs. first loading them on the virtual RAM disk. However, if you
460 remove them, the system has to update various files, something that
461 I<does> consume some space on the virtual RAM disk.)
471 Ubuntu is an extremely popular offshoot of Debian. It provides
472 cutting edge versions of many common tools, application and libraries
473 in an easy-to-run live CD configuration (and because a single download
474 option can be used for both live CD and install-to-disk usage, it
475 keeps your download options nice and simple). As with Debian 5, you
476 should be able to generate a fully function Catalyst environment in a
477 matter of minutes. Here are quick instructions on how to use Ubuntu
478 to prepare for the tutorial:
484 Download the Ubuntu Desktop edition and boot from the CD and/or image
485 file, select your language, and then "Try Ubuntu without any changes
490 Open a terminal session (click "Applications" in the upper-left
491 corner, then "Accessories," then "Terminal").
495 Add the 'universe' repositories:
497 sudo gedit /etc/apt/sources.list
499 And remove the comments from the lines under the comments about the
500 'universe' repositories.
507 sudo aptitude install libdbd-sqlite3-perl libcatalyst-perl libcatalyst-modules-perl libconfig-general-perl
509 Accept all of the dependencies. Done.
511 If you are running from the Live CD, you probably also want to free up
512 some disk space with the following:
516 NOTE: While the instructions above mention the live CD because that
517 makes it easy for people new to Linux, you can obviously also use one
518 of the options to install Ubuntu on your drive.
524 Matt Trout's C<cat-install>
526 Available at L<http://www.shadowcat.co.uk/static/cat-install>,
527 C<cat-install> can be a fairly painless way to get Catalyst up and
528 running. Just download the script from the link above and type C<perl
529 cat-install>. Depending on the speed of your Internet connection and
530 your computer, it will probably take 30 to 60 minutes to install because
531 it downloads, makes, compiles, and tests every module. But this is an
532 excellent way to automate the installation of all the latest modules
533 used by Catalyst from CPAN.
546 The 2008 Advent Day 4 entry has more information on using OpenBSD
547 packages to quickly build a system:
548 L<http://www.catalystframework.org/calendar/2008/4>.
552 NetBSD Package Collection on Solaris
554 The 2008 Advent Day 15 entry has more information on using C<pkgsrc> and
555 NetBSD packages on Solaris:
556 L<http://www.catalystframework.org/calendar/2008/15>.
562 You can get more information at
563 L<http://www.catalystframework.org/calendar/2008/7>
564 or L<Perl::Dist::CatInABox|Perl::Dist::CatInABox>.
568 Frank Speiser's Amazon EC2 Catalyst SDK
570 There are currently two flavors of publicly available Amazon Machine
571 Images (AMI) that include all the elements you'd need to begin
572 developing in a fully functional Catalyst environment within minutes.
573 See L<Catalyst::Manual::Installation|Catalyst::Manual::Installation>
580 For additional information and recommendations on Catalyst installation,
582 L<Catalyst::Manual::Installation|Catalyst::Manual::Installation>.
587 This tutorial will primarily focus on SQLite because of its simplicity
588 of installation and use; however, modifications in the script required
589 to support MySQL and PostgreSQL will be presented in Appendix.
591 B<Note:> One of the advantages of the MVC design patterns is that
592 applications become much more database independent. As such, you will
593 notice that only the C<.sql> files used to initialize the database
594 change between database systems: the Catalyst code generally remains the
598 =head1 WHERE TO GET WORKING CODE
600 Each chapter of the tutorial has complete code available as a tarball in
601 the main Catalyst Subversion repository (see the note at the beginning
602 of each part for the appropriate svn command to use).
604 B<NOTE:> You can run the test cases for the final code through Chapter 8
605 with the following commands:
607 sudo cpan Catalyst::Model::DBIC::Schema Time::Warp DBICx::TestDatabase \
608 DBIx::Class::DynamicDefault DBIx::Class::EncodedColumn
609 wget http://dev.catalyst.perl.org/repos/Catalyst/trunk/examples/Tutorial/MyApp_Chapter8.tgz
610 tar zxvf MyApp_Chapter8.tgz
612 CATALYST_DEBUG=0 prove --lib lib t
614 If you wish to include the L<HTML::FormFu|HTML::FormFu> section in
615 your tests, substitute C<MyApp_Chapter9_FormFu.tgz> for
616 C<MyApp_Chapter8.tgz> in the URL above. However, you will also need to
617 run the following additional commands:
619 sudo aptitude -y install libhtml-formfu-perl libmoose-perl \
620 libregexp-assemble-perl libhtml-formfu-model-dbic-perl
622 sudo cpan Catalyst::Component::InstancePerContext Catalyst::Controller::HTML::FormFu
624 You can also fire up the application under the development server that is conveniently
625 built in to Catalyst. Just issue this command from the C<MyApp> directory where you
626 ran the test suite above:
628 script/myapp_server.pl
630 And the application will start. You can try out the application by
631 pulling up C<http://localhost:3000> in your web browser (as mentioned
632 earlier, change C<localhost> to a different IP address or DNS name if
633 you are running your web browser and your Catalyst development on
634 different boxes). We will obviously see more about how to use the
635 application as we go through the remaining chapters of the tutorial, but
636 for now you can log in using the username "test01" and a password of
642 Kennedy Clark, C<hkclark@gmail.com>
644 Please report any errors, issues or suggestions to the author. The
645 most recent version of the Catalyst Tutorial can be found at
646 L<http://dev.catalyst.perl.org/repos/Catalyst/Catalyst-Manual/5.80/trunk/lib/Catalyst/Manual/Tutorial/>.
648 Copyright 2006-2008, Kennedy Clark, under Creative Commons License
649 (L<http://creativecommons.org/licenses/by-sa/3.0/us/>).