title: jQuery Bootgrid search error
body: <p>I am appending data to a table from within an ajax callback.</p>
  
  <pre><code>// ajax
  ...
  success: function(data) {
   $("#some-table").bootgrid("append", data.rows);
  },
  ..
  </code></pre>
  
  <p>It works as intended except the search.</p>
  
  <p>Search works for a single letter but then throws this error on an additional characters rendering it unusable.</p>
  
  <pre><code>Uncaught TypeError: Cannot read property 'search' of null
  </code></pre>
  
  <p>Its coming from this function in the lib</p>
  
  <pre><code>function loadData()
      {
          var that = this;
  
          this.element._bgBusyAria(true).trigger("load" + namespace);
          showLoading.call(this);
  
          function containsPhrase(row)
          {
              var column,
                  searchPattern = new RegExp(that.searchPhrase, (that.options.caseSensitive) ? "g" : "gi");
  
              for (var i = 0; i &lt; that.columns.length; i++)
              {
                  column = that.columns[i];
                  if (column.searchable &amp;&amp; column.visible &amp;&amp;
                      column.converter.to(row[column.id]).search(searchPattern) &gt; -1) // this is where it breaks
                  {
                      return true;
                  }
              }
  
              return false;
          }
  </code></pre>