title: Hiding markers using LeafletSlider?
body: <p>I am showing a temporal range of refugee camps on my map by using the <a href="https://github.com/dwilhelm89/LeafletSlider" rel="nofollow">LeafletSlider plugin</a>. The camps appear on the map based on an attribute in my GEOJSON object called <code>DATE_START</code>. As you can see in my <strong><a href="http://jsfiddle.net/doss1/sn02sna3/" rel="nofollow">JSFIDDLE</a></strong>, the slider works good. </p>
  
  <p>As I am scrubbing the timeline , I want to remove the markers that have a <code>DATE_CLOSED</code> property depending on the date of the current timeline scrub and the date of the <code>DATE_CLOSED</code> property. </p>
  
  <p><strong>It looks like this timeslider plugin only shows markers. Does anyone know how to hide the markers after it date has closed?</strong></p>
  
  <blockquote>
    <p>Sample data:</p>
  </blockquote>
  
  <pre><code>var camps = {"type":"FeatureCollection","features":[{"type":"Feature","properties":{"STATUS":"UNOCCUPIED","DATE_START":"2015-06-23","DATE_CLOSED":"2016-01-23"},"geometry":{"type":"Point","coordinates":[64.6875,34.97600151317591]}},{"type":"Feature","properties":{"STATUS":"OCCUPIED","DATE_START":"2014-01-21","DATE_CLOSED":"2015-05-25"},"geometry":{"type":"Point","coordinates":[65.335693359375,36.26199220445664]}},{"type":"Feature","properties":{"STATUS":"UNOCCUPIED","DATE_START":"2015-09-13","DATE_CLOSED":""},"geometry":{"type":"Point","coordinates":[67.587890625,35.969115075774845]}}]};
  </code></pre>
  
  <blockquote>
    <p>Code:</p>
  </blockquote>
  
  <pre><code>var map = L.map('map', {
  center: [33.67406853374198, 66.9287109375],
  zoom: 7
  }).addLayer(new L.TileLayer("http://{s}.tile.openstreetmap.org/{z}/{x}/{y}.png"));
  
  
  //Create a marker layer (in the example done via a GeoJSON FeatureCollection)
  var testlayer = L.geoJson(camps, {
  onEachFeature: function(feature, layer) {
      layer.bindPopup(feature.properties.DATE_START);
      }
  });
  
  var sliderControl = L.control.sliderControl({
  position: "topright",
  layer: testlayer,
  timeAttribute: 'DATE_START'
  });
  
  //Make sure to add the slider to the map ;-)
  map.addControl(sliderControl);
  
  sliderControl.options.markers.sort(function(a, b) {
  return (a.feature.properties.DATE_START &gt; b.feature.properties.DATE_START);
  });
  
  //And initialize the slider
  sliderControl.startSlider();
  
  $('#slider-timestamp').html(options.markers[ui.value].feature.properties.DATE_START.substr(0, 10));
  </code></pre>