CGI::Application Intro - Common usage

   customer.pl            product.pl                       order.pl
      |                      |                                |
      |                      |                                |
      v                      v                                v
 -----------------------------------------------------------------------
|                Base.pm   ( check_acl,  event_logging )                |
 -----------------------------------------------------------------------
                             |
                             |   Inherit check_acl, 
                             |  event_logging from Base.pm
                             v							
--------------------------------------------------------------------------		
  customer.pm                product.pm                      order.pm    |   
--------------------------------------------------------------------------  
      |                          |                              |  
      |	                         |                              |                                
      v                          v                              v
customer_related.pm           product._related.pm            order_related.pm
create/delete/edit customer   create/delete/edit product     create;/delete/edit order

CGI::Application Intro - Common usage

package MyApp::Base;
use base 'CGI::Application';

sub cgiapp_prerun { 
    my $self = shift;
    my $run_mode = shift;    
    # log action before it is executed
    $self->event_log("$user is executing $run_mode");
    
    # authorization - can user execute this runmode ?
    my $authorized  = 
          $self->check_permission_on_runmode( $user,  $run_mode );
    
    # user has no access, redirect to forbidden runmode
    $self->prerun_mode('forbidden') unless $authorized ;
}

# another example
our $TEMPLATE_OPTIONS = {
        INCLUDE_PATH => "$ENV{APP_ROOT}/templates",
    };
MyApp::Base->tt_config( TEMPLATE_OPTIONS => $TEMPLATE_OPTIONS );

CGI::Application Intro - useful methods

• prerun_run

• redirect planned runmode to other runmode.
• used in cgiapp_prerun only.
• user has no permission ? skip requested runmode and redirect to forbidden runmode.

• param() - setup your application properties and use it everywhere in your app.
• header_add - add cookie, type ( image, xls , pdf ... ).
• header_type - http 302 redirect etc

CGI::Application Intro - C::A plugins - CGI

• not really a plugin. CGI.pm is integrated with C::A




sub my_runmode {
	my $self = shift;
	# $query is the CGI object.
	$query = $self->query;  
    }

CGI::Application Intro - C::A plugins - TT

• CGI::Application::Plugin::TT - Template Toolkit plugin
• helps on separation of presentation and code.

    package MyApp::Product;
    sub list_products {
       my $self = shift;
       my $products = get_products();
       return $self->tt_process( "my.tmpl" , 
                       { products => $products } ); 
       # OR process template 
       # 'MyApp/Product/list_products.tmpl' 
       # return $self->tt_process( 
			{ products => $products } );
    }
    

CGI::Application Intro - C::A plugins - Stream

• CGI::Application::Plugin::Stream -Streaming file to browser

    use CGI::Application::Plugin::Stream (qw/stream_file/);
    sub excel_report {
        my $self = shift;
        $self->header_add( -type => 'application/x-sc',  
		 -attachment => "myfile.xls" );
        $self->stream_file("/path/to/myfile.xls");
    }
    

CGI::Application Intro - other C::A plugins

• CGI::Application::Plugin::ValidateRM - easy form validation
• CGI::Application::Plugin::LogDispatch - application logging
• CGI::Application::Plugin::Session - CGI::Session plugin

MyApp::EnvConfig

• contains only database info.



package MyApp::EnvConfig;

use strict;
use warnings;

our $DBName = 'dbi:Oracle:qa';
our $DBUser = 'user';
our $DBPass = 'password';
1;

• don't check this module into cvs ( thr .cvsignore )
• Production team creates it during first deployment

MyApp::Conf

• reads and access ini style config file
• MyApp::Conf

      package MyApp::Conf;
      use base 'YuSis::Conf';
      BEGIN { 
         __PACKAGE__->load_config( 
	               "$ENV{APP_ROOT}/conf/my.conf" ) 
      }

      1;    
      

• usages

        package MyApp::Product;
	use MyApp::Conf qw/MyConfig/;
	print MyConfig;
      

MyApp::DB

• provides easy access to DBI and DBIx::Simple handler
• DBIx::Simple is a thin layer around DBI to make query writing easier.
• example



package MyApp::DB::Product;
use base 'MyApp::DB';
	
sub list_products {
  my $self = shift;
  my $sql = q{ select id, name from product };
  my $products = 
       $self->dbh->selectcol_arrayref( $sql, 
                                  { Columns=>[1,2] });
  # or use a DBIx::Simple handler
  # my $products = 
  #   $self->db->query( $sql )->map;
  return $products; # { id => name. }
}	

YuSis::CAP::EventLogging

• a CGI::Application Plugin(CAP) for YuSis::EventLogging
• usage



package MyApp::Base;
use base 'CGI::Application';
use YuSis::CAP::EventLogging qw/elog elog_config/;

sub cgiapp_prerun {
  my $self = shift;
  $self->elog_config( 
                   { dbh  => MyApp::DB->dbh,
		    uname => $uname,
		   module_name => 'MyApp',
                     });			       
  $self->elog->log_event('log_in_ok') 
                if user_is_valid() ;
}

How to start a new project?

• decide a namespace for your app first.
• project_skeleton.pl creates the project directory structure and common modules.
• run project_skeleton.pl project_name
• see reference for download

Typical Application layout would be

• MyApp/lib/MyApp/Controller_1.pm
• MyApp/lib/MyApp/Controller_2.pm
• MyApp/lib/MyApp/DB/Model_1.pm
• MyApp/lib/MyApp/DB/Model_2.pm

Module Management

• CPAN modules (Pure perl / XS module )
• In house modules
• Krang Build System (see reference for a extration of the built system i did)

modules, plugins, and tools are great

• less code
• fewer bug
• code reuse
• rapid development
• and also...

modules, plugins, and tools are great

• less stress!!


no... that is not my baby :-)

things are still on the plate

• coding standard
• Perl Tidy
• Perl::Critic
• mod_perl

References

• C::A Wiki http://www.cgi-app.org/
• project_skeleton and module build tools
• Articles
• Using CGI::Application http://www.perl.com/lpt/a/549
• Rapid Website Development with CGI::Application http://www.perl.com/lpt/a/984
• Sample C::A web apps
• Smolder http://sourceforge.net/projects/smolder/
• Krang http://krang.sf.net