Hi there!
Related to my other topic around the building of a Search Results Layout, I have implemented this custom hook into the Dynamic Content to add a custom field to return the current search query, allowing me to include the search term in the title of the page. My implementation is very basic, simply using get_search_query() and surrounding it with quote marks if it exists:
case 'search_query':
$s = get_search_query();
$result = ( '' != $s ) ? "\"$s\"" : '';
break;
I could see this being expanded to offer access to any query vars present in the url, but just grabbing the search query was the most obvious and useful one that I have come across so far.
I have been able to hook in via the child-theme files, but figured this extension might be valuable to others as well, hence the feature request!
Cheers,