Angular 1.5 component attribute presence
<p>I'm refactoring some angular directives to angular 1.5-style components.</p>

<p>Some of my directives have behavior that depends on a certain attribute being present, so without the attribute having a specific boolean value. With my directives, I accomplish this using the link function:</p>

<pre><code>link: function(scope,elem,attrs, controller){
      controller.sortable = attrs.hasOwnProperty('sortable');
    },
</code></pre>

<p>How would I do this with the angular 1.5-style component syntax?</p>

<p>One thing I could do is add a binding, but then I'd need to specify the boolean value. I'd like to keep my templates as-is.</p>