Grails Layout setting active class for current "page" (controller + action)

gistfile1.gsp

<nav class="navbar navbar-default" role="navigation">
    <div class="container-fluid">
        <div class="collapse navbar-collapse" id="bs-example-navbar-collapse-1">
            <ul class="nav navbar-nav">
                <li class="${controllerName == null ? 'active' : ''}">
                	<a href="${createLink(uri:'/')}">Home</a>
                </li>
                <li class="${controllerName == 'blog' ? 'active' : ''}">
                	<a href="${createLink(uri: '/blog')}">Blog</a>
                </li>
            </ul>
        </div>
    </div>
</nav>