title: Using Variable to DataTables Server-Side Column value Formatter
body: <p>I want to pass PHP function on each cell of DataTables via Server-side Formatter, but PHP Function is dynamic. Here is example code:</p>
  
  <pre><code>$func_apply = $_GET['function_name']; // trim | strip_tags | md5 | ucwords
  
  $columns[] = array(
  'db'        =&gt; $field,
  'dt'        =&gt; '3',
  'formatter' =&gt; function( $d, $row ) {
                  return $func_apply($d);
              }
  );
  </code></pre>
  
  <p>But this way I am getting PHP error Undefined variable: $func_apply
  And if I put global $func_apply; within anonymous function then it gives Fatal error: Function name must be a string in ...</p>