Perl_and_Catalyst.Josh_Poritz

							Perl and Catalyst: The Chemistry
  Just Couldn’t be Any Better.




               Josh Poritz
Why do people complain about perl?

  $;=pop;{$.=         perl           -e'map\
   0;map{$;%$_        {map{print       chr }/\d\
   or$.||=$_}2            {3}/gx      }join q{},\
   ..sqrt$;;;+             split/\s/sx,q(0741171151\
   $.||die$;-j               16032097110111116104101\
   .$/;warn$..                    114 032    080 10 1\
   $/;$;/=$.;n                    114 108    032 104 \
   until+redo}                    09 70        99 10\
                                  7   1        0   1\
 Given a positive                 1     1    4     0\
                                  4       4 )      ;'
 integer argument,
 display all of its           print “Just Another Perl
 prime factors.               Hacker”
But in the case of a web app…

   Time-to-market often takes precedent over
    systematic engineering approach
    –   CRUD/Search/Validation system in just 188 lines of code
   Grabs input from eclectic sources: web
    forms, database, external services, etc.
    Natural result: text processing dominates
    application logic.
   Platform independence of client & server
    systems loom essential
TMTOWTDI: The bedrock of perl

   “There’s More Than One Way To Do It”
    (pronounced TimToady)
   Language doesn’t tell the programmer how to
    program.
   Write programs the way your brain concocts
    them; minimal translation needed.
   Opposite of Zen of Python: “There should be
    one – and preferably only one – obvious
    away to do it.”
TMTOWTDI: Enter Catalyst

                                                     Template
             DBIx::Class
                                                      Toolkit




             MODEL                                   VIEW

                                                                HTML::
 Net::LDAP                 Plucene          Mason
                                                                Mason




                      CONTROLLER: Catalyst plugins
DRY, DRY, DRY – how many times do I
need to tell you?
Robust handling of URLs

/songs/list/byAlbum?title=love
     package MusicApp::Controller::Songs;

     sub list : Local {
           my ($self, $c, $ord) = @_;
           my $title =
                 $c->req->params->{title};
           ...
           $c->stash->{template} =
                 ‘songs/list.tt2’;
     }
Of course, there are plenty of wrong
ways to write perl code…

http://www.youtube.com/watch?v=KyLqUf4cdwc