NAME

       CGI::Application::Plugin::ErrorPage - A simple error page plugin for CGI::Application

SYNOPSIS

         use CGI::Application::Plugin::ErrorPage 'error';

         sub my_run_mode {
           my $self = shift;

           eval { .... };

           if ($@) {
               # Send the gory details to the log for the developers
               warn "$@";

               # Send a comprehensible message to the users
               return $self->error(
                   title => "Technical Failure',
                   msg   => "There was a techical failure during the operation.",
               );
           }

         }

DESCRIPTION

       This plugin provides a shortcut for the common need of returning a simple error message to
       the user.

       You are encouraged to provide a template file so that the error messages can be presented
       with a design consistent with the rest of your application.

       A simple design is provided below to get to you started.

   A better default error page.
       If you don't install an AUTOLOAD run mode in the normal way in "setup", this plugin will
       automatically install a reasonable default at the "prerun" stage, which returns an error
       page like this:

         return $c->error(
             title => 'The requested page was not found.',
             msg => "(The page tried was: ".$c->get_current_runmode.")"
         );

   Relation to error_mode()
       CGI::Application includes "error_mode()" to provide custom handling when the application
       dies.  This error() routine provides a shortcut for displaying error messages to the user.
       So, they both have a place on their own, and it could make sense to use them together. In
       your 'error_mode' routine, you might call error() to return a message to the user:

           $self->error( title => 'Technical Failure', msg => 'There was a technical failure' );

   Suggested Uses
       Some common cases for returning error messages to the user include:

         * "Technical Failure" - The software failed unexpectedly
         * "Insufficient Information" - some required query parameter was missing
         * "Request Not Understood" - Some value we received in the query just didn't make sense.

   Silliness
         [22:36] <rjbs> Techno Failure.  We were cruising along and rocking out while fulfilling your request, but then the music stopped and we sort of got distracted.
         [22:36] <rjbs> Tek Failure.  Too busy reading Shatner novels to respond to your request.

METHODS

   error()
               return $self->error(
                   title => "Technical Failure',
                   msg   => "There was a techical failure during the operation",
               );

       Nothing fancy, just a shortcut to load a template meant to display errors. I've used it
       for the past several years, and it's been very handy to always have around on projects to
       quickly write error handling code.

       It tries to load a template file named 'error.html' to display the error page.

       If you want to use a different location, I recommend putting something like this in your
       base class, so you only have to provide your error template location once.

        # In this case, intentionally *don't* import 'error' to avoid a "redefined" warning.
        use CGI::Application::Plugin::ErrorPage;
        sub error {
             my $c = shift;
             return $c->CGI::Application::Plugin::ErrorPage::error(
                 tmpl => $self->cfg('ROOT_URI').'/path/to/my/alternate/error/file.html',
                 @_,
             );
        }

       This module intentionally ignores any "tmpl_path()" set by application, since this is
       usually an indication of where the intended file is located, not the error template.  This
       exceptional handling of the "tmpl_path()" is one of the only value added bits of logic
       that this plugin adds. The rest of it is primarily a simple recommendation for error page
       handling wrapped up as a module.

       If you don't want this behavior, it's simple enough just to roll your own error() page
       method and skip using this plugin. Here's the simple essential code:

           use Params::Validate ':all';
           sub error {
               my $self  = shift;
               my %p = validate(@_, { title => SCALAR, msg => SCALAR });
               my $t = $self->load_tmpl;
               $t->param( title => $p{title}, msg => $p{msg} );
               return $t->output;
           }

   Example error.html
       Here's a very basic example of an "error.html" file to get you started.

        <!DOCTYPE html
                PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
                 "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
        <html xmlns="http://www.w3.org/1999/xhtml" lang="en-US" xml:lang="en-US">
        <head>
        <title><!-- tmpl_var title escape=HTML --></title>
        <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
        </head>
        <body>
        <h1><!-- tmpl_var title escape=HTML--></h1>
        <p><!-- tmpl_var msg escape=HTML --></p>
        </body>
        </html>

       We manage site-wide designs with Dreamweaver and keep a basic 'error.html' that uses a
       generic Dreamweaver 'page.dwt' template with standard EditableRegion names. That way, we
       can copy this error.html into a new Dreamweaver-managed project and have the new design
       applied to it easily through Dreamweaver.

SUPPORT

       Ask for help on the CGI::Application mailing list. Report bugs and wishes through the
       rt.cpan.org bug tracker.

AUTHOR

           Mark Stosberg
           CPAN ID: MARKSTOS
           mark@summersault.com

COPYRIGHT

       This program is free software; you can redistribute it and/or modify it under the same
       terms as Perl itself.

       The full text of the license can be found in the LICENSE file included with this module.

SEE ALSO

       perl(1).