noob q: external modules

[EdwardsMike]

Hi! I am fairly new to Mojolicious and am working on an app that will accept an uploaded file and display some details about that file. I have already written a module to parse these files and I believe I should have it under lib/MyApp/Model, but where to I put the "use" declaration (I assume in the main package under lib) and then do I need to declare a "helper" to use a command from the module?

[ghandmann]

Hi there and welcome to Mojolicious. ;)

To help you with this, it basically boils down to two options:

1. If you are using the "single file app" where the entire app lives in just one file. Then you simply have to add your use My::Module to the top and start using your module.

2. When you are using the "fully fledged MVC setup" with multiple files for Views, Models and Controllers you need to add the use My::Module to the file that actually wants to use it. This could be a Controller. But it also could be a Model or a View.

It may make sense to register a helper for your module, if you need to access it from multiple locations in your app or if it depends on configuration values. Because a helper my access many usefull objects like the "Mojolicious::Plugin::Config"-Instance.

[ghandmann]

You are right, the lib folder of your "project" should be added to @INC be default. Therefore you can place your custom Modules there and load them via use MyModule;.

If you place a module under lib/MyApp/Model/MyModule.pm then your module has to declare a matching package name like package MyApp::Model::MyModule; and you have to use it accordingly with use MyApp::Model::MyModule.

[Grinnz]

See the examples at the end of https://metacpan.org/pod/Mojolicious::Guides::Cookbook#Making-your-application-installable describing how to have your application load relative lib directories properly, or use https://metacpan.org/pod/lib::relative, or add the absolute path in PERL5LIB in your application's environment before starting it.

[EdwardsMike]

Yeah, I thought I had it set up right, but I still get an error "Undefined subroutine &MailDatEditor::Controller::App::maildat_report" even though I am explicitly use-ing it (see below). Permissions are all fine. If I call the module as part of @inc (where it also lives), it works (sorta).

package MailDatEditor::Controller::App;
use Mojo::Base 'Mojolicious::Controller', -signatures;
use MailDatEditor::Model::MAILDAT qw( maildat_report ); # <- works if called as "use EGA::MAILDAT" since that's in @INC

# This action will render a template
sub upload ( $self ) {

  # Render template "app/upload.html.ep" with message
  $self->render( msg => 'MAIL.DAT Uploader' );
}

sub display( $self ) {
    my $file	= $self->param( 'md_file' );
    my $MAILDAT	= maildat_report( $file );
    $self->render( report => $MAILDAT );
 }
1;

[Grinnz]

For use MailDatEditor::Model::MAILDAT qw( maildat_report ); to import a usable function maildat_report, there must be a module at MailDatEditor/Model/MAILDAT.pm within one of the directories added to your lib paths, which starts with package MailDatEditor::Model::MAILDAT;, and which includes sub maildat_report, use Exporter 'import';, and our @EXPORT_OK = 'maildat_report';, or similar.

[EdwardsMike]

THAT was the problem! I had simply copied my module from /usr/local/... to the Model dir. Changing the package line is what I was missing. Thank you for your help!