On: How a Clojure pet project turned into a full-blown...

[weavejester]

HTML isn't meant to handle presentation. Ideally, it's a way of marking up content to allow an arbitrary presentation layer to be laid on top.

I prefer generating HTML content through s-expressions. It's more flexible and concise than a templating library, and it forces you to bear in mind the separation of content and presentation. In turn, this makes it easier to unit-test the views, and to write automated integration tests.

For instance, if I were a designer writing a template, I have control over both the CSS and the HTML. This might tempt me to write the HTML around a particular design:

  <div class="post">
    <div class="small">
      <%= post.points %> points by <%= author.name %>
    </div>
  </div>

But if I am a programmer, without necessarily much knowledge of the presentation, I might be more careful to write more semantic HTML that's presentation-neutral.

  [:div.post {:id (str "post-" (:id post))}
    [:div.header
      [:span.points (:points post)]
      " points by "
      [:span.author (:name author)]]

Which has the useful side effect of making it easier to write tests:

  (is (= (css-select "#post-1 .author" (:body response))
         "Test User"))