HAML: RoR's new templating engine

Saturday, September 16

I’m typing this from an internet cafe in London right now. One pound for one hour’s worth of internet access is a great deal.

So, I was holding off on writing about HAML until it was officially unveiled at RailsConf Europe where it’s creator and I were graciously flown by our employer, Unspace Interactive. Now that the conference is over, it’s time to spread the word.

HAML is a new templating engine for Rails that enables you to write truly beautiful templates. Created by one of my esteemed collegues, Hampton Catlin, I’m proud to say that I played a minor role in its evolution: I refactored the codebase, added some tests, and wrote the rdoc. The real credit goes to Hampton, of course. I’m merely a supplicant and a votary. But I’m the only HAML commiter besides Hampton, which makes me better than you.

HAML in action

Let’s take a breif look at HAML in action:

%html
  %head
    %title HAML Demo
  %body
    #container
      .content
        %p Stop. HAML time

That’s it. No annoying tags to close, no need to specify the tag name when all we want is a div, and best of all, the # and . characters mimic those of CSS. Here’s the output:

<html>
  <head>
    <title>HAML Demo</title>
  </head>
  <body>
    <div id='container'>
      <div class='content'>
        <p>Stop. HAML time</p>
      </div>
    </div>
  </body>
</html>

Now that your mind has been completely blown, you should download HAML and try it for yourself.

Resources for your reading pleasure

Installation as a Rails plugin

HAML is available as a Rails plugin. To install it, type the following from the root of your Rails project:

./script/plugin install svn://hamptoncatlin.com/haml/trunk

Once installed, you can start creating templates with the .haml extension.

PS: I have yet to mention Unspace on this blog. Thankfully, I work there now. With Hampton, Pete, Ryan, Anthony, and John. More about that soon, swear to god.

Comments

Leave a response

  1. rubylicious – September 16, 2006 @ 12:30 PM

    I’ve looked through tons of templatesystems through the years and I have to say that this looks really fresh.. is there support comming for multiple rubylines for loops etc?

  2. Packagethief – September 17, 2006 @ 05:04 AM

    The jury is still out on whether or not we’ll add support for blocks and loops, but multiple lines might be a possibility in the near future. A few people have submitted patches; we’ll look more closely at them when we get back from London.

    We’re also going to be adding the ability to use HAML as a straight-up engine (sans Rails project) so you can require it in your Ruby programs and go to town.