#!/usr/bin/env perl
use Mojolicious::Lite;
use utf8;

my @entries = ();

get '/' => sub {
    my $self = shift;
    $self->stash(
        entries => \@entries
    );
    $self->render('index');
};

post '/post' => sub {
    my $self = shift;
    my $entry = $self->param('body');
    push @entries, $entry;
    $self->stash(body => $entry);
    $self->redirect_to('/');
};

app->start;
__DATA__

@@ index.html.ep
% layout 'default';
% title '入力フォーム';
%= form_for '/post' => method => 'POST' => begin
  %= text_field 'body'
  %= submit_button '投稿する'
% end
% for my $entry (@{$entries}) {
    <p><%= $entry %></p>
% }

@@ layouts/default.html.ep
<!DOCTYPE html>
<html>
  <head><title><%= title %></title></head>
  <body><%= content %></body>
</html>