HTML needed for loader:

The loader itself:

    
      <div id="loader-one" class="loader-container" style="display: none;">
        <div class="loader"></div>
      </div>
    
  

A sample button to activate it:

    
      <button class="btn btn-primary compare-submit">Toggle Loader</button>
    
  

A sample button logic that uses a global tekFn object:

    
      // == Event Listener ==
      $('button.compare-submit').on("click", showHideLoader);
      // == Actions ===
      function showHideLoader() {
        var $loader = $('#loader-one');
        (!$loader.hasClass('active')) ?
          window.tekFn.loader('show','#loader-one')+$loader.addClass('active') : 
          window.tekFn.loader('hide','#loader-one')+$loader.removeClass('active');
      }
    
  

Toggle Loader