Clojure, Enlive: how to use negation when using multi-step for selector?

Question

I'm using Enlive for Clojure. I'm trying to get span tags with class "title" within li tags, within a specific div tag.

<div class="main">
    <li><span class="title">wanted</span></li>
    <li><span class="title">wanted</span></li>
    <li class="dummy"><span class="title">NOT wanted</span></li>
</div>

But, I want to exclude span tags within li tags that have class name "dummy". The code below works as expected:

(html/select (html/select src [:div.main]) [[:li (html/but 
:li.dummy)] :span.title])

The question is how to make this work with just one selection call. I wasn't able to use 'but' negation with multiple steps and ended up using nested 2 select calls.

Can anybody put these into one single select expression?

Answer 1

My guess is that the selector you came up with was exactly the right one.

The reason why it didn’t match is rather that your HTML is not well-formed – remember that the default TagSoup parser tries to sanitise your input. In your fragment you have list items outside of a list context, and so TagSoup closes the wrapping <div> early.

You must wrap your list items in a list, for example <ol>:

<div class="main">
    <ol>
        <li><span class="title">wanted</span></li>
        <li><span class="title">wanted</span></li>
        <li class="dummy"><span class="title">NOT wanted</span></li>
    </ol>
</div>

Then the following selector should do it:

(html/select src [:div.main [:li (html/but :.dummy)] :span.title])