Hi,

You can't directly put PHP into the field, but you can use jQuery to apply values generated by PHP. For example, put into Properties->Custom Classes "php-checkbox1" for a checkbox (without ""), "php-text1" for a text field, then add a Code Block (Source) type Javasript position Header with something like:

$(function() { // on page structure loaded

  var phpYesNo = <?php echo $variable ? 'true' : 'false'; ?>; // transform to true or false
  var phpText = <?php echo $variableText; ?>; // text value - write as is

  $('.php-checkbox1  input').prop('checked', phpYesNo);
  $('.php-text1  input').val(phpText);

});

It allows a lot of manual intervention in case of need, so for a professional nearly all is possible.