render_exeption() and render_not_found() example.

app.pl

#!/usr/bin/env perl
use Mojolicious::Lite;

get '/divide/:dividend/by/:divisor' => sub {
  my $self = shift;
  my $dividend = $self->param('dividend');
  my $divisor  = $self->param('divisor');

  return $self->render_not_found 
    unless $dividend =~ /^\d+$/ && $divisor =~ /^\d+$/;

  return $self->render_exception('Divide by zero') if $divisor == 0;
  
  $self->render_text( $dividend / $divisor );
};

app->start;