title: Open Layers 3 Zoom map event handler
body: <p>I need to handle a zoom event in Open Layers 3.</p>
  
  <p>The following is my code:</p>
  
  <pre><code>map_object = new ol.Map({
  target: 'map',
  controls: controls_list,
  interactions: interactions_list,
  overlays: [overlay],
  layers: [OSM_raster, WFS_layer],
      view: view
  });
  
  
  map_object.on("Zoom", function() {
    console.log('Zooming...');
  });
  </code></pre>
  
  <p>This code runs with no errors and shows a map, but there is no output to the console, suggesting this function isn't firing.</p>
  
  <p>I have also tried:</p>
  
  <pre><code>map_object.on("drag", function() {
    console.log('Dragging...');
  });
  </code></pre>
  
  <p>And this too does nothing.</p>
  
  <p>Any help as to how to handle map control events in OL3 would be much appreciated (particularly zooming!).  Note I have tried 'zoom' as well as 'Zoom' for the type field of the on method.</p>