Alternative Dancer Templating Engines

Dancer uses a simple model of interfacing with templating engines (based on Dancer::Template::Abstract) and makes it very easy to add support for new engines. Thanks to this, if you're not happy with the default simple engine or with Template Toolkit, there is now a dozen different alternatives to choose from. Let's take a look at some of them.

Dancer::Template::Tiny

Template::Tiny is a lightweight engine which reimplements a subset of Template Toolkit features. As the name implies, it aims to accomplish this with as little code as possible. If you're using just the basic functionality of Template Toolkit, you should be able to switch to Template::Tiny without any modifications to template files (and you can easily go back at any moment).

Dancer::Template::Tiny is going to replace Dancer::Template::Simple as the default templating engine in Dancer2.

Example template:

<html>
  <head>
    <title>Tiny Example</title>
    <link rel="stylesheet" href="[% request.uri_base %]/css/style.css" />
  </head>
  <body>
    <h1>Hello, World! This is Dancer [% dancer_version %]!</h1>
    <p>
      [% IF morning %]
        Good morning!
      [% ELSE %]
        Good afternoon!
      [% END %] 
    </p>
  </body>
</html>

Route handler:

use DateTime;
    
get '/hello' => sub {
    template 'hello', { morning => (localtime)[2] < 12, now => DateTime->now };
};

Dancer::Template::Tenjin

Tenjin is a very fast templating engine with implementations for many languages -- including, of course, Perl. Its great performance comes from the fact that it uses the underlying language's constructs to process templates, instead of defining its own templating language and having to parse it. Support for this engine in Dancer is provided by Dancer::Template::Tenjin.

Example template:

<html>
  <head>
    <title>Tenjin Example</title>
    <link rel="stylesheet" href="[== $request->uri_base =]/css/style.css" />
  </head>
  <body>
    <h1>Hello, World! This is Dancer [= $dancer_version =]!</h1>
    <p>
      <?pl if ((localtime)[2] < 12) { ?>
        Good morning!
      <?pl } else { ?>
        Good afternoon!
      <?pl } ?>
    </p>
    <p>
      Current time is: [== DateTime->now->hms =]
    </p>
  </body>
</html>

Route handler:

use DateTime;
    
get '/hello' => sub {
    template 'hello';
};

Dancer::Template::Haml

Haml, which stands for "HTML Abstraction Markup Language", brings a fresh, different approach to templating. It aims at making templates short, clean, and as easy to read as well-formatted source code. Dancer::Template::Haml is a wrapper around Text::Haml and lets you use Haml templates in Dancer applications.

Example template:

%html
  %head
    %title Haml Example
    %link(rel="stylesheet" href="#{$request->uri_base}/css/style.css")
  %body
    %h1 Hello, World! This is Dancer #{$dancer_version}!
    %p
      - if ((localtime)[2] < 12) {
        Good morning!
      - } else {
        Good afternoon!
      - } 
    %p Current time is: #{DateTime->now->hms}

Route handler:

use DateTime;
    
get '/hello' => sub {
    template 'hello';
};

More

There are many more interesting templating engines ready to be used with Dancer, such as Mason (provided by Dancer::Template::Mason) or Xslate (Dancer::Template::Xslate). Do a CPAN or MetaCPAN search for "dancer template" to get a list of all the available engines, and choose the one that suits you best. In the true spirit of Perl, there's more than one way to write a template!

Author

Michal Wojciechowski, <odyniec@odyniec.net>

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