How to Select Element That Does Not have Specific Class

This selects the second LI element.

document.querySelector("li:not([class])")

or

document.querySelector("li:not(.completed):not(.selected)")

Example:

// select li which doesn't have a 'class' attribute...
console.log(document.querySelector("li:not([class])"))

// select li which doesn't have a '.completed' and a '.selected' class...
console.log(document.querySelector("li:not(.completed):not(.selected)"))

 <ul id="tasks">
    <li class="completed selected">One Task</li>
    <li>Two Task</li>
  </ul>

To select the <li> that has not completed nor selected class:

document.querySelector("li:not(.completed):not(.selected)");

Fiddle

http://jsfiddle.net/Z8djF/

You can try the :not() selector

var completeTask = document.querySelector("li:not(.completed):not(.selected)");

http://jsfiddle.net/UM3j5/

Try getting an array of the parent's children instead:

var completeTask = document.querySelector("#tasks").childNodes;

Then loop/search them as necessary.

document.querySelectorAll('[wf-body=details] input:not(.switch):not(.btn)').forEach(function(e){
    // do whatever you want. with 'e' as element :P
});