ecohack example by andrewxhill

index.html

<!DOCTYPE html>
<html>
  <head>
    <title>Animals | CartoDB.js</title>
    <meta name="viewport" content="initial-scale=1.0, user-scalable=no" />
    <meta http-equiv="content-type" content="text/html; charset=UTF-8"/>
    <link rel="shortcut icon" href="//cartodb.com/assets/favicon.ico" />
    <style>
      html, body, #map {
        height: 100%;
        padding: 0;
        margin: 0;
      }

      #layer_selector {
        position: absolute;
        top: 20px;
        right: 20px;
        padding: 0;
      }

      #layer_selector ul {
        padding: 0; margin: 0;
        list-style-type: none;
      }

      #layer_selector li {
        border-bottom: 1px solid #999;
        padding: 15px 30px;
        font-family: "Helvetica", Arial;
        font-size: 13px;
        color: #444;
        cursor: auto;
      }

      #layer_selector li:hover {
        background-color: #F0F0F0;
        cursor: pointer;
      }

      #layer_selector li.selected {
        background-color: #EEE;
      }
    </style>

    <link rel="stylesheet" href="//libs.cartocdn.com/cartodb.js/v3/themes/css/cartodb.css" />
    <!--[if lte IE 8]>
        <link rel="stylesheet" href="//libs.cartocdn.com/cartodb.js/v3/themes/css/cartodb.ie.css" />
    <![endif]-->

    <script type="sql/html" id="sql_template">
    </script>
  </head>
  <body>
    <div id="map"></div>
    <div id="layer_selector" class="cartodb-infobox">
      <ul id="selector">
        <li id="all" class="selected">All</li>
      </ul>
    </div>

    <!-- include cartodb.js library -->
    <script src="//libs.cartocdn.com/cartodb.js/v3/cartodb.js"></script>

    <script>
      var queries = {}, selectedFilter;
      // create layer selector
      function createFilter(layers) {

        var $options = $('#layer_selector li');
        $options.click(function(e) {
          // get the area of the selected layer
          var $li = $(e.target);
          var query = $li.attr('id');
          if(selectedFilter != query ){
            // change the style in the layer to update the map
            // console.log("SELECT ST_MakeLine(the_geom_webmercator) the_geom_webmercator FROM ("+queries[query]+") k")
            layers[1].getSubLayer(0).setSQL("SELECT ST_MakeLine(the_geom_webmercator) the_geom_webmercator FROM ("+queries[query]+") k");
            layers[1].getSubLayer(1).setSQL(queries[query]);
            layers[2].setSQL(queries[query]);
            selectedFilter = query;
          }
        });
      }

      function main() {


        // get the currently selected style
        selectedFilter = $('li.selected').attr('id');

        queries["all"] = "SELECT * FROM animals";

        var sql = new cartodb.SQL({ user: 'seatheanimals' });
        sql.execute("SELECT type, count(*) AS c FROM all_animals WHERE type IS NOT NULL GROUP BY type ORDER BY c DESC")
           .done(function(data){
            for (i in data.rows){
              $('#selector').append(
                $('<li></li>').attr('id', data.rows[i].type).html(data.rows[i].type + ' (' + data.rows[i].c+ ')')
              );
              queries[data.rows[i].type] = "SELECT * FROM animals WHERE id IN (SELECT id FROM all_animals WHERE type = '"+data.rows[i].type+"')";
            }
           })

        cartodb.createVis('map', '//seatheanimals.cartodb.com/api/v2/viz/7ee4a392-6dbd-11e4-b416-0e018d66dc29/viz.json')
        .done(function(vis, layers) {
          // layer 0 is the base layer, layer 1 is cartodb layer
          // console.log(layers)
          createFilter(layers);
        })
        .error(function(err) {
          console.log(err);
        });
      }

      window.onload = main;
    </script>
  </body>
</html>