A mentee asked me over the week­end if there was a way with­in a Mojolicious web appli­ca­tion to store the routes sep­a­rate­ly from the main appli­ca­tion class. Here’s one way. These instruc­tions assume you’re using Perl 5.34 and Mojolicious 9.19 (the lat­est as of this writ­ing) via the ter­mi­nal com­mand line on a Linux, Unix, or macOS sys­tem; make the appro­pri­ate changes if this does­n’t apply to you.

First, if you haven’t already, cre­ate your Mojolicious app at your shell prompt:

$ mojo generate app Local::RouteDemo
  [mkdir] /Users/mgardner/Projects/blog/local_route_demo/script
  [write] /Users/mgardner/Projects/blog/local_route_demo/script/local_route_demo
  [chmod] /Users/mgardner/Projects/blog/local_route_demo/script/local_route_demo 744
  [mkdir] /Users/mgardner/Projects/blog/local_route_demo/lib/Local
  [write] /Users/mgardner/Projects/blog/local_route_demo/lib/Local/RouteDemo.pm
  [exist] /Users/mgardner/Projects/blog/local_route_demo
  [write] /Users/mgardner/Projects/blog/local_route_demo/local-route_demo.yml
  [mkdir] /Users/mgardner/Projects/blog/local_route_demo/lib/Local/RouteDemo/Controller
  [write] /Users/mgardner/Projects/blog/local_route_demo/lib/Local/RouteDemo/Controller/Example.pm
  [mkdir] /Users/mgardner/Projects/blog/local_route_demo/t
  [write] /Users/mgardner/Projects/blog/local_route_demo/t/basic.t
  [mkdir] /Users/mgardner/Projects/blog/local_route_demo/public
  [write] /Users/mgardner/Projects/blog/local_route_demo/public/index.html
  [mkdir] /Users/mgardner/Projects/blog/local_route_demo/templates/layouts
  [write] /Users/mgardner/Projects/blog/local_route_demo/templates/layouts/default.html.ep
  [mkdir] /Users/mgardner/Projects/blog/local_route_demo/templates/example
  [write] /Users/mgardner/Projects/blog/local_route_demo/templates/example/welcome.html.ep
$ cd local_route_demo

Create a new Perl mod­ule in your edi­tor for stor­ing your routes. Here we’re using Local::RouteDemo::Routes:

$ touch lib/Local/RouteDemo/Routes.pm
$ $EDITOR lib/Local/RouteDemo/Routes.pm

Make the mod­ule with a func­tion that will cre­ate the routes you want, giv­en a Mojolicious::Routes object. Here we’re just bring­ing over the default route cre­at­ed when we cre­at­ed our app:

package Local::RouteDemo::Routes;
use strict;
use warnings qw(all -experimental::signatures);
use feature 'signatures';
use Exporter 'import';
our @EXPORT_OK = qw(make_routes);

sub make_routes ($router) {
    $router->get('/')->to('Example#welcome');
    # add more routes here

    return;
}

1;

Adjust the appli­ca­tion class to load your new Routes mod­ule and call its export­ed function:

package Local::RouteDemo;
use Mojo::Base 'Mojolicious', -signatures;
use Local::RouteDemo::Routes 'make_routes';

# This method will run once at server start
sub startup ($self) {

    # Load configuration from config file
    my $config = $self->plugin('NotYAMLConfig');

    # Configure the application
    $self->secrets($config->{secrets});

    # Make routes
    make_routes($self->routes);

    return;
}

1;

Finally, run your tests and/​or man­u­al­ly test your routes to be sure every­thing works OK:

$ prove -vlr t
t/basic.t .. [2021-06-07 12:21:55.36917] [58779] [debug] [elVGykGVWlOt] GET "/"
[2021-06-07 12:21:55.36972] [58779] [debug] [elVGykGVWlOt] Routing to controller "Local::RouteDemo::Controller::Example" and action "welcome"
[2021-06-07 12:21:55.37137] [58779] [debug] [elVGykGVWlOt] Rendering template "example/welcome.html.ep"
[2021-06-07 12:21:55.37343] [58779] [debug] [elVGykGVWlOt] Rendering template "layouts/default.html.ep"
[2021-06-07 12:21:55.37495] [58779] [debug] [elVGykGVWlOt] 200 OK (0.005772s, 173.250/s)

ok 1 - GET /
ok 2 - 200 OK
ok 3 - content is similar
1..3
ok
All tests successful.
Files=1, Tests=3,  1 wallclock secs ( 0.02 usr  0.01 sys +  0.38 cusr  0.11 csys =  0.52 CPU)
Result: PASS
$ script/local_route_demo get /
[2021-06-07 12:22:29.55930] [58889] [debug] [f3YoaFhkwJ42] GET "/"
[2021-06-07 12:22:29.55990] [58889] [debug] [f3YoaFhkwJ42] Routing to controller "Local::RouteDemo::Controller::Example" and action "welcome"
[2021-06-07 12:22:29.56059] [58889] [debug] [f3YoaFhkwJ42] Rendering template "example/welcome.html.ep"
[2021-06-07 12:22:29.56269] [58889] [debug] [f3YoaFhkwJ42] Rendering template "layouts/default.html.ep"
[2021-06-07 12:22:29.56432] [58889] [debug] [f3YoaFhkwJ42] 200 OK (0.005004s, 199.840/s)
<!DOCTYPE html>
<html>
  <head><title>Welcome</title></head>
  <body><h2>Welcome to the Mojolicious real-time web framework!</h2>
<p>
  This page was generated from the template "templates/example/welcome.html.ep"
  and the layout "templates/layouts/default.html.ep",
  <a href="/">click here</a> to reload the page or
  <a href="/index.html">here</a> to move forward to a static page.
</p>
</body>
</html>

You can find a git repos­i­to­ry of this work on GitHub, and here’s a com­mit of all the changes made to the default Mojolicious appli­ca­tion so you can see the differences.

Update

Joel Berger from the Mojolicious project told me at The Perl and Raku Conference that it would be more idiomat­ic to use a Mojolicious plu­g­in rather than a plain mod­ule with an export, so here you go:

lib/Local/RouteDemo.pm:

package Local::RouteDemo;
use Mojo::Base 'Mojolicious', -signatures;

# This method will run once at server start
sub startup ($self) {

    # Load configuration from config file
    my $config = $self->plugin('NotYAMLConfig');

    # Configure the application
    $self->secrets($config->{secrets});

    # Add routes from plugin
    $self->plugin('Local::RouteDemo::Plugin::Routes');

    return;
}

1;

lib/Local/RouteDemo/Plugin/Routes.pm:

package Local::RouteDemo::Plugin::Routes;
use Mojo::Base 'Mojolicious::Plugin', -signatures;

sub register ($self, $app, $conf) {
    my $r = $app->routes;

    $r->get('/')->to('Example#welcome');
    # add more routes here

    return;
}

1;