How to create a simple Web application with CGI::Application Template::Toolkit and DBIx::Class Leonard Miller February 7, 2009

Who is this talk for? Need to write web applications Don’t want/cannot have a heavy framework Experienced Programmers. Know about CPAN, how to learn from CPAN’s documentation. Newer programmers that could use a new/better way to organize their code.

Why these three Modules? Separate out the code to MVC Pieces Each can be used/tested alone The modules themselves are easy to use and understand

Why not Catalyst? mod_perl/fastcgi: You don’t always have the access on the machine to get Catalyst to work. CGI::Application is a ‘lite’ framework, and as such is much smaller. Not as big and scary. Trivial to install in a local ~/lib dir

What is MVC MVC stands for Model-View-Controller

What is MVC MVC breaks the work into three parts Model - Short for database model. DBIx::Class does all the database work: inserts/queries. View - Template::Toolkit does all the view/html work. Controller - CGI::Application holds all the logic to glue the Model and the View together.

What is MVC Who has seen code like this: use DBI; my $sql = "select * from users"; my $dbh = DBI->connect( $ds, $un, $pw ); my $sth = $dbh->prepare($sql); $sth->execute(); print "Content-type: text/html\r\n\r\n"; while (my $h = $sth->fetchrow_hashref()) { print ”Name is:".$h->{'first_name'}." \n"; }

What is MVC Who has seen code like this: use DBI; my $sql = "select * from users"; my $dbh = DBI->connect( $ds, $un, $pw ); my $sth = $dbh->prepare($sql); $sth->execute(); print "Content-type: text/html\r\n\r\n"; while (my $h = $sth->fetchrow_hashref()) { print ”Name is:".$h->{'first_name'}." \n"; }

What is MVC Who has seen code like this: my $q = new CGI; if ($q-> param('first_name' eq ''){ print input_form(); } else{ my $sql = "insert into users..."; my $sth = $dbh->prepare($sql); $sth->execute(); print submission_form(); }

What is MVC Who has seen code like this: my $q = new CGI; if ($q-> param('first_name' eq ''){ print input_form(); } else{ my $sql = "insert into users..."; my $sth = $dbh->prepare($sql); $sth->execute(); print submission_form(); }

What is MVC Any questions regarding what MVC is?

CGI::Application A sample program: Helloworld.cgi <- config info HelloWorldCgiApp.pm <- controller Html files: <- View –header.html –body.html –footer.html DB/Main.pm <- Model –DB/Main/Users.pm –DB/Main/Artists.pm –DB/Main/CDs.pm

CGI::Application helloworld.cgi: use HelloWorldCgiApp; my $helloworld = HelloWorldCgiApp->new(); $helloworld->run();

CGI::Application helloworld.cgi (with config info): use HelloWorldCgiApp; my $helloworld = HelloWorldCgiApp->new ( PARAMS => { tt_config => { INCLUDE_PATH => ".", PRE_PROCESS => 'header.html', POST_PROCESS => 'footer.html', }, hw_string => "Hello world!", }, ); $helloworld->run();

CGI::Application helloworld.cgi (with config info): use lib “~/testdir”; use HelloWorldCgiApp; my $helloworld = HelloWorldCgiApp->new ( PARAMS => { tt_config => { INCLUDE_PATH => ".", PRE_PROCESS => ‘test/header.html', POST_PROCESS => ‘test/footer.html', }, hw_string => "Hello test world!", }, ); $helloworld->run();

CGI::Application HelloWorldCgiApp (continued): package HelloWorldCgiApp; use base 'CGI::Application'; use Template; sub setup { my $self = shift; $self->run_modes( 'mode1' => 'start’, 'mode2' => 'sec_page' ); $self->start_mode('mode1'); }

CGI::Application HelloWorldCgiApp (continued): package HelloWorldCgiApp; use base 'CGI::Application'; use Template; sub setup { my $self = shift; $self->run_modes( 'mode1' => 'start’, 'mode2' => 'sec_page' ); $self->start_mode('mode1'); } $q -> param (‘rm’);

CGI::Application HelloWorldCgiApp (continued): sub start { my $self = shift; my $tt_config = $self->param(‘tt_config’) my $tt = Template->new( $tt_config ); $tt->process('body.html', { hwstr => 'hi world!!!', }, \$html); return $html; }

CGI::Application HelloWorldCgiApp (continued): sub cgiapp_prerun { my ($self, $runmode) my $q = $self->query; #things you need to run every time #input validation etc. #logging }

DBIx::Class The mysql table: CREATE TABLE users ( user_id INT NOT NULL PRIMARY KEY AUTO_INCREMENT, first_name varchar(75) NOT NULL, last_name varchar(75) NOT NULL, country_code CHAR(2) NULL ); | user_id | first_name | last_name | country_code | | 1 | joe | user | US | | 2 | Steve | Jobs | US | | 3 | Bill | Gates | US | | 4 | Larry | Wall | US |

DBIx::Class DB/Main.pm package DB::Main; use base qw/DBIx::Class::Schema/; __PACKAGE__->load_classes(); 1;

DBIx::Class DB/Main/User.pm package DB::Main::User; use base qw/DBIx::Class/; __PACKAGE__-> load_components(qw/PK::Auto Core/); __PACKAGE__->table('users'); __PACKAGE__->add_columns(qw/ user_id first_name last_name country_code /); __PACKAGE__-> set_primary_key('user_id');

DBIx::Class Using the DBIx::Class Module HelloWorldCgiApp.pm: use DB::Main; my $schema = DB::Main-> connect('dbi:mysql:db','user', 'password'); = $schema->resultset('User')->all; my $users_rs = $schema->resultset('User'); my $user = $users_rs ->next; $tt->process('body.html', { users => ], user => $user, }, \$html);

DBIx::Class Using the Module – inserts: my $new_user = $schema-> resultset('User')->new({ last_name => $last_name, first_name => $first_name, }); $new_user->insert;

DBIx::Class Things that you still need to do: Verify your data -- this is good practice under any circumstances Open your database connection Error handling -- did the DB connection open? Did the sql succeed? Unlike some larger frameworks, CGI::Application will not do the error checking for you. It’s a lite framework, so you still need to do some work

Template::Toolkit Why use Template::Toolkit? –Common ‘look and feel’ templates. Easy to change for those people who are better at design than we are. –What type of data is It good for? arrays hashes scalars

Template::Toolkit Any html file is a TT file! Simplest usage for a scalar: [% var_name %]

Template::Toolkit Usage for an Array where users is an array: [% FOREACH item IN users %] [% item %] [% END %]

Template::Toolkit Usage where item is a hash: [% item.user_id %] [% item.first_name %] [% item.last_name %] [% item.country %]

Template::Toolkit Usage for an Array where users is an array of hashes (like an array of rows from a database): [% FOREACH item IN users %] [% item.user_id %] [% item.first_name %] [% item.last_name %] [% item.country %] [% END %]

Template::Toolkit Usage for an Array where users is an array of hashes (like an array of rows from a database): <input type=“hidden” name=“rm” value=“page_2” [% FOREACH item IN users %]... [% END %]

There’s more available CGI::Application::Plugin::AbstractCallback CGI::Application::Plugin::ActionDispatch CGI::Application::Plugin::ActionDispatch::Attributes CGI::Application::Plugin::AnyCGI CGI::Application::Plugin::AnyTemplate CGI::Application::Plugin::AnyTemplate::Base CGI::Application::Plugin::AnyTemplate::ComponentHandler CGI::Application::Plugin::AnyTemplate::Driver::HTMLTemplate CGI::Application::Plugin::AnyTemplate::Driver::HTMLTemplateExpr CGI::Application::Plugin::AnyTemplate::Driver::HTMLTemplatePluggable CGI::Application::Plugin::AnyTemplate::Driver::Petal CGI::Application::Plugin::AnyTemplate::Driver::TemplateToolkit CGI::Application::Plugin::Apache CGI::Application::Plugin::Apache2::Request CGI::Application::Plugin::Apache::Request CGI::Application::Plugin::Authentication CGI::Application::Plugin::Authentication::Driver CGI::Application::Plugin::Authentication::Driver::Authen::Simple CGI::Application::Plugin::Authentication::Driver::CDBI CGI::Application::Plugin::Authentication::Driver::DBI CGI::Application::Plugin::Authentication::Driver::DBIC CGI::Application::Plugin::Authentication::Driver::Dummy CGI::Application::Plugin::Authentication::Driver::Filter::crypt CGI::Application::Plugin::Authentication::Driver::Filter::lc CGI::Application::Plugin::Authentication::Driver::Filter::md5 CGI::Application::Plugin::Authentication::Driver::Filter::sha1 CGI::Application::Plugin::Authentication::Driver::Filter::strip CGI::Application::Plugin::Authentication::Driver::Filter::uc CGI::Application::Plugin::Authentication::Driver::Generic CGI::Application::Plugin::Authentication::Driver::HTPasswd CGI::Application::Plugin::Authentication::Store CGI::Application::Plugin::Authentication::Store::Cookie CGI::Application::Plugin::Authentication::Store::Session CGI::Application::Plugin::Authorization CGI::Application::Plugin::Authorization::Driver CGI::Application::Plugin::Authorization::Driver::DBI CGI::Application::Plugin::Authorization::Driver::Dummy CGI::Application::Plugin::Authorization::Driver::Generic CGI::Application::Plugin::Authorization::Driver::HTGroup CGI::Application::Plugin::Authorization::Driver::SimpleGroup CGI::Application::Plugin::AutoRunmode CGI::Application::Plugin::AutoRunmode::FileDelegate CGI::Application::Plugin::BREAD CGI::Application::Plugin::BrowserDetect CGI::Application::Plugin::CAPTCHA CGI::Application::Plugin::CHI CGI::Application::Plugin::Cache::Adaptive CGI::Application::Plugin::CaptureIO CGI::Application::Plugin::CompressGzip CGI::Application::Plugin::Config::Any CGI::Application::Plugin::Config::Context CGI::Application::Plugin::Config::General CGI::Application::Plugin::Config::IniFiles CGI::Application::Plugin::Config::Simple CGI::Application::Plugin::Config::YAML CGI::Application::Plugin::ConfigAuto CGI::Application::Plugin::DBH CGI::Application::Plugin::DBIProfile CGI::Application::Plugin::DBIProfile::Data CGI::Application::Plugin::DBIProfile::Graph::GDGraphInline CGI::Application::Plugin::DBIProfile::Graph::HTML CGI::Application::Plugin::DBIProfile::Graph::HTML::Horizontal CGI::Application::Plugin::DBIProfile::Graph::HTMLBarGraph CGI::Application::Plugin::DBIProfile::Graph::SVGTT CGI::Application::Plugin::DebugMessage CGI::Application::Plugin::DebugScreen CGI::Application::Plugin::DevPopup CGI::Application::Plugin::DevPopup::HTTPHeaders CGI::Application::Plugin::DevPopup::Log CGI::Application::Plugin::DevPopup::Timing CGI::Application::Plugin:: CGI::Application::Plugin::Eparam CGI::Application::Plugin::ErrorPage CGI::Application::Plugin::Feedback CGI::Application::Plugin::FillInForm CGI::Application::Plugin::Flash CGI::Application::Plugin::FormState CGI::Application::Plugin::FormValidator::Simple CGI::Application::Plugin::Forward CGI::Application::Plugin::HTCompiled CGI::Application::Plugin::HTDot CGI::Application::Plugin::HTMLPrototype CGI::Application::Plugin::HelpMan CGI::Application::Plugin::HtmlTidy CGI::Application::Plugin::I18N CGI::Application::Plugin::JSON CGI::Application::Plugin::LinkIntegrity CGI::Application::Plugin::LogDispatch CGI::Application::Plugin::Mason CGI::Application::Plugin::Menu CGI::Application::Plugin::MessageStack CGI::Application::Plugin::MetadataDB CGI::Application::Plugin::Output::XSV CGI::Application::Plugin::PageBuilder CGI::Application::Plugin::ParsePath CGI::Application::Plugin::Phrasebook CGI::Application::Plugin::ProtectCSRF CGI::Application::Plugin::RateLimit CGI::Application::Plugin::Redirect CGI::Application::Plugin::RequireSSL CGI::Application::Plugin::Routes CGI::Application::Plugin::RunmodeDeclare CGI::Application::Plugin::Session CGI::Application::Plugin::Stash CGI::Application::Plugin::Stream CGI::Application::Plugin::TT CGI::Application::Plugin::TT::LastModified CGI::Application::Plugin::TemplateRunner CGI::Application::Plugin::Thumbnail CGI::Application::Plugin::TmplInnerOuter CGI::Application::Plugin::ValidateRM CGI::Application::Plugin::View::HTML::Template CGI::Application::Plugin::ViewCode CGI::Application::Plugin::YAML

Questions?

Thank you Leonard Miller February 7th Frozen Perl 2009