Perl Dancer Template headers, footers

I'm learning Perl and using Dancer as a web framework. I've got two views (tt files) which should share the same navigation. So, it would be great to start learning how to manage templates for navigation and footers.

I've read the documentation for the Template Toolkit and I've done the following:

I've changed the config.yml file to:

#template: "simple"

template: "template_toolkit"
engines:
     template_toolkit:
     start_tag: '[%'
     end_tag:   '%]'

I've defined the templates in the .pm file:

package proyecto;
use Dancer ':syntax';

our $VERSION = '0.1';

get '/' => sub {
    template 'index';
};


get '/menu' => sub {
    template 'menu';
};

true;

There is a link in the index template directing the visitor to the menu template:

<li class="active">< a href="/menu">Menu <span class="sr-only"></span></a></li>

I would like to reuse the navigation code from index.tt into menu.tt, so I've wrapped the navigation code in index.tt with the following:

[% BLOCK navigation %]
#my nav code
[% END %]

To finally include that code in the menu.tt file, I've written the following (where the navigation code should be):

[% navigation = 'index.tt' %]
[% INCLUDE navigation %]

The files index.tt and menu.tt are located in the folder views. But it seems it's not that easy! =( Any suggestion on how to reuse code from one file to another which is located in the same directory?

Solution

This is what layouts are for. The idea is that content common to all pages (e.g. header, footer, navbar) goes in the layout and content specific to each page goes in templates called views. Views are called "partials" in other frameworks because they only contain the content for part of the page.

If you use the dancer command line utility to set up your application, the default layout is views/layouts/main.tt and looks something like this:

<!DOCTYPE html>
<html>
<head>
  <meta http-equiv="Content-type" content="text/html; charset=<% settings.charset %>" />
  <title>Foo</title>
  <link rel="stylesheet" href="<% request.uri_base %>/css/style.css" />
</head>
<body>
  <% content %>
  <div id="footer">
    Powered by <a href="http://perldancer.org/">Dancer</a> <% dancer_version %>
  </div>
</body>
</html>

The <% content %> section is replaced with the specified view when you call template 'view';. (In your case, you'll need to change <% and %> to [% and %] since you're using the Template Toolkit-style delimiters.)

For example, if views/index.tt is:

<h1>Hello, World!</h1>

calling template 'index'; in a route renders the following:

<!DOCTYPE html>
<html>
<head>
  <meta http-equiv="Content-type" content="text/html; charset=utf-8" />
  <title>Foo</title>
  <link rel="stylesheet" href="http://www.example.com/css/style.css" />
</head>
<body>
  <h1>Hello, World!</h1>
  <div id="footer">
    Powered by <a href="http://perldancer.org/">Dancer</a> 1.3202
  </div>
</body>
</html>

Note that there's already a footer section; you just have to add elements for a header and navbar.

If this is new development, you should really be using Dancer2 instead of Dancer (fortunately, layouts and views are the same in both).