title: Add button in a new row on datatable, getting undefined
body: <p>I have a javascript object, Im trying to add a new row to the datatable. One column is a field and the other column should contain a button.</p>
  
  <pre><code>var appendLastCategory = function() {
      var obj = {
          id: 'jh2i4h34ubi43',
          name: 'Lolo',
      };
      $('#categoriesList').DataTable().row.add({
          name: obj.name, //First column
          mRender: function() { //Second column
              return "&lt;a class='md-btn' onClick='deleteCategory(this, &amp;quot;" + obj.id + "&amp;quot;)'&gt;Delete&lt;/a&gt;";
          }
      }).draw();
  };
  </code></pre>
  
  <p>Then when I click in the "Delete" button, Im getting 'undefined' in the 'id' value. And I don't know why, because when I initialize the table filling it with the initial data and using the 'mRender' mostly the same way, it works.</p>
  
  <pre><code>var deleteCategory = function(element, id) {
      console.log(id);
      //Blah blah, all the code to delete on backend and remove the row
  };
  </code></pre>